PEDOLOGIE Edité avec l'aide financière de la Fondation Universitaire

et du Ministère de l'Education nationale et de la Culture française et du Ministère de l'Education nationale et de la Culture néerlandaise

Uitgegeven met de financiële steun van de Universitaire Stichting en van het Ministerie van Nationale Opvoeding en Nederlandse Cultuur

en van het Ministerie van Nationale Opvoeding en Franse Cultuur

Bulletin de la Société BeIge de Pédologie

Bulletin van de Belgische Bodemkundige Vereniging

1981

XXXI, 2

Comité de rédaction Redactiecomité

A. Cottenie, J. D'Hoore, G. Hanotiaux, A. Herbillon, T. Jacobs, A. Noirfalise, G. Scheys, C. Sys,

R. Tavernier, M. Van Ruymbeke, W. Verheye.

PRESIDENT D'HONNEUR ERE-VOORZITTER

J. Baeyens

SECRETAIRES GENERAL HONORAIRES ERE-SECRET ARISSEN -G ENERAAL

R. Tavemier J. Ameryckx C. Sys

ANClENS PRESIDENTS OUD-VOORZITTERS

V. Van Straelen t F. Jurion t L. De Leenheer G. Manil t A. Van den Hende G. Scheys L. Sine t A. Cottenie G. Hanotiaux M. De Boodt A. Herbillon P. Avril J. D'Hoore M. Van Ruymbeke

(1950-1953 ) (1954-1955 ) ( 19 56-1 957) ( 1 9 5 8-1 9 59 ) (1960-1961) (1962-1963) (1964-1965 ) (1966-1967) (1968-1969) ( 1 970-1 9 71 ) (1972-1973 ) (1974-1975) (1976-1977) (1978-1979 )

_ .. "._- -1 • TA E1 ~

PEDOLOGIE, XXXI, 2, p. 147-168,4 tab., 1 fig., Ghent 1981.

THE FAO AGRO-ECOLOGICAL ZONE APPROACH TO DETERMINATION OF LAND POTENTlAL

G. M. HIGGINS A.H. KASSAM

INTRODUCTION

The abUity of land to produce crops is limited and the limits to pro­duction are set by climate and soU conditions, and by the use and management applied to the land. Accordingly, knowledge on land resource endowment and its potential is an essential prerequisite to planning of optimum land use and subsequent sound 'long term' agri-cultural development. .

In particular, for planning optimum land use, answers are needed to the following questions : - is there sufficient land to meet future food needs ? - where are the potential arabie areas and what is their extent ? - for which crops are they suitable and what is the range of their

potential ? - which level of technology is required under these various circum­

stances? - what is the risk of degradation and what measures are required to

minimize this risk ? - where can maximum returns from increased inputs be obtained and

on what crops ? - what levels of investment are needed to obtain these returns ? - what are the limitations to production increases ? - where should research efforts be concentrated ?

Attempts to answer such questions have engaged the minds of men for many years but even appraisals of the extents of arabie lands vary

Higgins G. M. & A. H. Kassam - Respectively Project Coordinator and Consultant Soil Resources, Management and Conservation Service, Land and Water Develop­ment Division, F.A.O., Rome, Italy.

147

widely (DudaI1978). Additionally, such estimates do not take into account differences in production potential when it is calculated for : a) different crops (with widely differing climatic and soil requirements, e.g. pearl millet and white potato) and b) different levels of inputs and technology (e.g. subsistence cultivation and commercial production) . Such factors must be taken into account to arrive at realistic estimates of agricultural production potentials.

Aware of these facts FAO initiated, in September 1976, a study of potentialland use by agro-ecological zones to obtain a first approxima­tion of the production potential of the world 's land resources, and so provide the physical data base necessary for planning future agricultur­al development. Initially the project dealt with rainfed production potential, at two levels of inputs, for eleven crops in developing countries (FAO 1978a, 1978b and FAO 1980b).

The present paper outlines the methodology used in the study, details the climatic and soil inventories used and illustrates results through consideration of the potential for wheat and cassava produc­tion.

METHODOLOGY

The study is based on the 1:5 million FAO/Unesco Soil Map of the World (FAO, 1969-80) on which is superimposed a specially created climatic inventory characterizing temperature and moisture regimes rnatched to crop requirements. It is confined to the rainfed production potential of specific crops under two levels of inputs and uses most of the land evaluation principles and concepts developed over the last ten years by the FAO and Dutch inter-disciplinary land evaluation groups (FAO, 1976). In essence the methodology comprises: i. selection and definition of land utilization types (crop and produce,

production type, input level); ii. division of the crops of the study into groups based on differences

in their photosynthesis pathways and the response of photosynthesis to temperature and radiation, and compilation of a crop adaptability inventory including crop phenological climatic requirements;

iii. assemblage of information on the soil requirements of the crops, at each of the two levels of inputs envisaged;

iv. compilation of a quantitative climatic inventory (1:5 million scale) based on major climates (characterizing temperature differences) and lengths of growing periods (characterizing time available when water and tem perature permit crop growth) from station data on climate and water balance;

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v. computer assemblage of a soil inventory, by countries, from the FAO/Unesco Soil Map of the World;

vi. overlay of the climatic inventory on the soil map and area measure­ment of resultant climate/soil units;

vii. computer calculation (from v and vi) of country extents of soil units (by slope class, texture class and phase) by major climates and growing period zones (30 day intervals ) ;

viii. matching of the climatic inventory (iv) with the crop groups (ii) and, where the climatic requirements of the crop groups are met, calculation of biomass and constraint-free individual crop yields by growing period zones;

ix. matching of the soil requirements of crops (iii) with the soil units, slope classes, texture classes and phases of the soil map, by rating soillimitations at each of the two levels of inputs;

x. compilation and rating of the various agro-climatic constraints to crop production occurring in the various major climates and growing period zones;

xi. application of the agro-climatic constraints (x) to the constraint­free crop yields (viii) to derive anticipated (agro-climatically attain­able) crop yields, by growing period zones;

xii. agro-climatic suitability classification of each growing period zone according to anticipated crop yields (xi);

xiii. computer application of the soillimitation ratings on the agro­climatic suitability ·classification of each growing period zone accord­ing to the soil composition of the zone, to; arrive at the land suit­ability classification i.e. extents of land variously suited to the pro­duction of the crop at each level of inputs.

Details of the climatic, soil and land inventories (steps iv, v and vi) usedïn the study are presented in the following sections.

THE CLIMATIC INVENTORY

The usefulness of a climatic inventory, for predicting agro-climatic suitability for crop growth, is dependent on how far the climatic re­quirements of crops can be matched with the climatic parameters used in the inventory. Therefore, data on the climatic requirements of crops is an essential prerequisite to the compilation of any climatic inventory to be used for assessment of agro-climatic crop suitab ility .

To aid the compilation of such data on climatic requirements, crops can be classified lnto climatic adaptability groups acc·órding to their fairly distinct photosynthesis characteristics (Kassam, 1980a). Because photosynthesis is temperature dependent, prevailing temperature con-

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ditions determine which crop groups can be grown and which cannot and thus this climatic parameter is an essential component of any climatic inventory for crop suitability. Four such temperature related erop groups have been formulated (Kassam, Kowal & Sarraf, 1977) for F AO's assessments of land potential, namely : - " Group I crops, e.g. spring wheat, winter wheat, highland phaseolus

bean, winter potato, winter badey, with a C3 photosynthesis path­way, with an optimum temperature for maximum photosynthesis of lS-200 C and adapted to operate under moderately cool and cool conditions (mean daily temperature S-200 C).

- Group 11 crops, e.g. soybean, cotton, sweet potato, cassava, ground­nut, paddy rice, with a C3 photosynthesis pathway, with an optimum temperature for maximum photosynthesis of 2S-300 C and adapted to operate under warm conditions (mean daily temperature >200 C).

- Group 111 crops, e.g. pead millet, lowland sorghum, lowland màize, sugarcane, with a C4 photosynthesis pathway, with an optimum temperature for maximum photosynthesis of 30-3SOC and adapted ' to operate under warm conditions (mean daily temperature >200 C).

- Group IV crops, e.g. highland sorghum, highland maize, with a C4 photosynthesis pathway, with an optimum temperature for phöto­synthesis of 20-300 C and adapted to operate under moderately cool conditions (mean daily temperature lS-200 C) .

Prevailing temperature threshold values of at least 50, 150 and 200C are therefore of paramount importance in climatic inventories intend­ed for assessment of crop suitability.

Providing that temperature requirements are met, the degree of success in the growth of a crop is largely dependent on how well its optimum length of growth cycle fits with the period when water is available for growth. Curtailment of the growth cycle is naturally re­flected by decreased yield and the same is true for enforced extended growth cycles. Accordingly, under rainfed conditions, the time when water. is available for crop growth is also of vital importance for any assessment of cr op suitability. If this (with radiation and temperature data) is known, climatically potential crop yields, in suitable prevailing temperature regimes, can be quantified. Subsequent application of cr op specific agro-climatic constraints (e.g. rainfall variability, pests and diseases) as related to various environmental conditions, allows quantification of agro-climatically obtainable yields.

Recognizing these facts, the climatic inventory created by the FAO study of necessity characterizes both heat and moisture conditions. This was achieved through the concept of the length of growing period,

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being defined as the duration (in days) when both water and tempera­ture permit crop growth. A moisture supply from rainfall of half, or more than half, potential evapotranspiration has been considered to permit crop growth. Mean daily temperatures greater than 50 C have been considered as being conduc ive to growth.

Quantification of the heat attributes during the growing period is achieved by classifying major climates defining the actual temperature regime during the growing period as shown intable 1 (FAO, 1980 b). Each of the 14 major climates recognized in the study is thus defined. The temperature thresholds used in these definitions accord with those differentiating the four major crop groups previously described and therefore allow matching of the temperature requirements of the crops with the temperature parameters used in the climatic inventory. In this way the crops which can be considered as 'possible' for growth in the different major climates are distinguished, as shown in the ultimate column of table 1.

Quantification of moisture conditions in the growing period is based on a water balance model comparing precipitation (P) with potential evapo~ranspiration (PET).

The data utilized for the calculation of the water balance and for further climate-related calculations, comprises meteorological station records where extended data on rainfall, maximum and minimum temperatures, vapour pressure, wind speed and sunshine duration is available on a monthly and yearly basis (Frère, 1976). In areas where data are incomplete, interpolation from other observed or estimated climatic elements is carried out and compared with data obtained from neighbouring stations.

The following main concepts, definitions and methodologies are employed in the model (FAO, 1978a).

a. Beginning of growing period. The beginning of the growing period is taken as the time when precipitation equals half-potential evapo­transpiration (P= 0.5 PET).

This premise takes into account the fact that the anlount of moist­ure required to sustain growth of germinating crops is much below the full rate of evapotranspiration and during crop emergence it approxim­ates to about 0.5 PET. Therefore, the amount of precipitation that is equal to (or greater than) 0.5 PET has been considered as being sufficient to meet the water requirements of establishing crops, and consequently, in the model, the time when P = 0.5 PET is taken as the beginning of the growing period.

b. Humid period. A normal growing period is defined as one with a period when there is an excess of precipitation over potential evapo-

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Table 1

Characteristics of major climates

Climate Major climates during 24-hr Mean Suitable for growing period temperature consideration

(Oq regime (during the NO Descriptive name during the growing period)

growing period for crop group

Tropics 1 Warm tropics More than 20 II and lil All months with monthly

2 mean temperatures, Moderately cool tropics 15 - 20 I and IV

corrected to sea level, 3 Cool tropics SIlO - 15 I above 18°C

Cold tropics Less than 5 Not suitable 4

Sub-tropics 5 Warmlmoderately cool More than 20 II and III One or more months with sub-tropics (summer monthly mean tempera- rainfall) tures, corrected to sea

6 Warmlmoderately cool 15 - 20 I and IV level, below 18°C but all months above 50 C

sub-tropics (summer rainfall)

7 Warm sub-tropics More than 20 II and III (summer rainfall)

8 Moderately cool sub- 15 - 20 I and IV tropics (summer rain'-fall)

9 Cool sub-tropics 5/10 - 15 I (summer rainfall)

10 Cold sub-tropics Less than 5 Not suitable (summer rainfall)

11 Cool sub-tropics 5/10-20 1 (winter rainfáll)

12 Cold sub-tropics Less than 5 Not suitable (winter rainfall)

Temperate 13 Cool temperate SilO - 20 I One or more months with

14 Cold temperate Less than 5 Not suitable monthly mean tempera-tures, corrected to sea level, below 50 C

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transpiration, i.e. a humid period. Such é). period not only meets the . full evapotranspiration demands of crops with a complete or maximul1l canopy cover, but also replenishes the moisture deficit of the soil profile.

c. End oof growing period. During the 'post humid' period, precipi­tation is again less than potential evapotranspiration and crops begin to draw upon water stored in the soil. Subsequently, the frequency and amount of precipitation decreases sharply and rainfall deficit in­creases. This results in a marked alteration of the environment and triggers pronounced changes in physiological responses of crops. Under such conditions, and in the absence of soil moisture reserves, crops are forced to mature when precipitation is equal to or less than 0.5 PET. The time wher P = 0.5 PET in the 'post humid' period is taken as the end of rains and rainy season. However, the growing period for most crops continues beyond the rainy season and, to a greater or lesser extent, crops of ten mature on moisture reserves stored in the soil profue. Soil moisture storage must therefore be considered in defining the length of the growing period. However, the amount of soil moisture stored in the soil profile, and available to a crop, varies with the depth of the profile, the soil's physical characteristics, the rooting pattern of the crop and other factors. Furthermore, changes in soil moisture reserve lead to changes in the actual evapotranspira­tion rate.

lil the model, a general figure of 100 mm storage water has been assumed as being available to crops. Accordingly, the time taken to evapotranspire this 100 mm of storage water (or less if 100 mm excess precipitation is not available in the humid period) has been added to the duration of the rainy season, to set the end of the growing period. The choice of 100 mm is based on evidence which indicates that annual crops can utilize stored soil moisture in the range of 75-125 mm, by the time of harvest. Where storage water is likely to be less than 100 mm due to soil characteristics (e.g. shallow soil depth), this is taken into account °in the soil ratings used in computation of the !and suitability as described in the Land Inventory Section.

in addition to normal growing periods, as defined above, three other types of water available growing periods have been recognized and inventoried, namely : - All year round humid growing period. The average monthly precipit­

ation, for every month of the year, exceeds the full rate of the average monthly potential evapotranspiration. Two subidivisions are recognized namely (a) areas with a rainfall deficit in some part of the year (365- days) and (b) are as with no rainfall deficit for any period in the year (365+ days).

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- Intermediate growing period. Throughout the year, the average monthly precipitation does not exeeed the fuil rate of the average monthly potential evapotranspiration, but it does exeeed half the potential evapotranspiration.

- All year round dry period. The ave rage monthly precipitation for every month of the year is lower than half the average monthly potential evapotranspiration.

when the length of growing period is determined by both moisture and temperature eonstraints, the model first quantifies the periods when water is available for erop growth. SubsequentIy, in appropriate areas, these values are redueed by the period of time when erop growth is limited by temperature.

In locations where sueh periods of time are equal (or greater than) the water available periods, the areas are designated as having no grow­ing period (0 Cold) (i.e. major climates 4, 10, 12 and 14, table 1). In loeations where the low tem perature periods only partIy restriet growth, appropriate reduetions are applied to the ealeulated water available periods to arrive at the growing periods, i.e. the period during whieh temperatures lower than 50 C oeeur is subtraeted from the ealeulated water availability period, to arrive at a growing period when both water and temperature permit erop growth. As illustrated, this period ean show a diseontinuity.

150 days

Beginning

-_. ~ ~ i-

End

90 days I

water availability period = 150 days

period with mean temperatures below 50 C = 30 days

growing period = t'20 days

The compilation of the area inventory of lengths and types of growing periods, by the major climates reeognized, is undertaken on the 1:5 million FAO/Unesco Soil Map of the world by : 1. plotting the individual station values of the temperature regime

during the growing period and the length (in days) of the growing period;

ii. identifying areas with similar major climates and delineating these regions;

üi. eonstrueting isolines of growing periods with values of 0, 75, 90,

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Table 2

Extents (million ha) of major climates and grouped lengths of growing period zones in the developing world

Growing period zones(days) 365+ 1270-3651180-270175-180 11-75 I p I Totals

Tropics Warm 212.8 1 305.5 968.0 805.9 486.6 301.4 40802 Cool 3.1 68.6 76.6 88.0 22.6 18.8 277.7 Cold - - - - - 36.8 36.8

Suh-tropics Warm - 14.0 157.1 130.8 107.7 310.6 720.2 slimmer rainfall) Cool 5.8 51.0 37.9 50.5 27.0 23.2 195.4

Cold - - - - - 36.1 36.1

Suh-tropics Cool 3.5 5.3 41.8 120.6 136.7 748.3 1 056.3 (winter rainfall) Cold - - - - - 138.2 138.2

Temperate Cool - - - 13.9 46.4 6.7 67.0 Cold - - - - - 21.0 21.0

Totals 225.2 1444.4 1 281.4 1 209.7 827.0 1 641.1 6 628.8

120,150,180,210,240,270,300,330,365- and 365+ days de­lineating length of growing period zones of 0-74 days, 75-89 days, 90:-119 days, etc.

Where station data are limited, altitude data, rainfall information and land use maps provide guidance for the map compilations.

A summarized inventory of major climates and lengths of growing period zones, in the Developing World, is presented in table 2.

THE SOIL INVENTORY

The FAO/Unesco Soil Map of the World (FAO,1969-80) is used as the base for the study, not only for provision of essential soil, slope, texture and phase data but also as the physical map base of the land inventory. Certain attributes of the map are particularly pertinent to the land inventory and are accordingly described.

The legend of the Soil Map of the World comprises 106 different soil units (26 major soil units).

The mapping units employed on the maps are associations of soli units and are usually composed of a dominant soil and of associated soils. Each of the latter occupies at least 20 percent of the area of a mapping unit. Important soils which cover less than 20 percent of the area of a mapping unit are added (dealt with) as inclusions. While the composition and ex tent of each soil association is given on the reverse of each respective map sheet and in the explanatory texts of

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the map, areas covered byeach soil unit are not available. The follow­ing relative distribution of dominant soils, associated soils and inclu­sions is used to determine are as of individual soil units, according to the composition of the soil association in respect of the number of associated soils and the number of inclusions.

Table 3

Examples of relative distribution of dominant soil, associated soil(s) and inc1usion(s), expressed in percentage of the area of the mapping units, according to the com­position of the mapping unit

Dominant soil Associated soil(s) Inc1usion(s)

Percentage of area Number Percentage of area Number Percentage of area

100 0 0 0 0 70 1 30 0 60 1 30 1 10 60 2 20 + 20 0 0 50 2 20 + 20 1 10 30 3 20 + 20 + 30 1 10 50 1 30 2 10 + 10 40 1 30 3 10 + 10 + 10 50 1 30 4 5+5+5+5 40 2 20 + 20 2 10 + 10 30 2 20 + 20 3 10 + 10 + 10 30 3 20 + 20 + 20 2 5+5 25 3 20 + 20 + 20 3 5+5+5 24 3 20 + 20 + 20 4 4+4+4+4

The mapping unit symbol of the soil associations, also provides in­formation on : (a) slope class (level/rolling/mountainous)

(b) texture class (coarse/medium/fine), and (c) phase (if present).

In achieving the transformation of extents of mapping units into extents of individual soil units, the following rules are applied, to­gether with the mapping unit composition rules, to allocate appropriate texture and slope classes, and phase distribution, to all constituent soils. 1. The texture class description (i.e. 1,2, or 3) applies to the dominant

soil of the mapping unit. Where two texture classes are indicated they each apply to 50 percent of the dominant soil unit. Dominant soils of mapping units where texture is not described, and all associated and included soils, are considered as medium textured (i.e. texture 2), with certain specific soil unit exceptions.

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ii. The slope class description (i.e. a, b or c) applies to the dominant soil of the mapping unit. Where two slope classes are indicated, they each apply to 50 percent of the dominant soil unit. Dominant soils of mapping units where slope is not described and all associated and included soils, are allocated soil unit specific slope classes.

iü. Where only major soil units are designated e.g. undifferentiated Cambisols (B), it is assumed that the unit consists of the first in­dividual soil unit listed under the major unit heading; i.e. in the case of Cambisols the applicable soil unit would be Eutric Cambisols (Be).

ivo The phase designation, when present, applies to the dominant soil in the mapping unit, all associated soils and inclusions being consider­ed unaffected.

THELANDINVENTORY

Superimposition of the climatic inventory on the Soil Map of the World allows the creation of unique zones within which soil and climatic conditions are known and quantified (Higgins and Kassam 1980). Af ter compilation, area measurement of each soil mapping unit is effected as it occurs in each length of growing period, in each major clim.ate and in each country.

This measurement is effected by á. 2 mm (1 00 km 2) grid count correct­ed for reported areas of countries' land masses. The data are used as follows to create the land inventory of extents of soil units, broken down by slope and texture class and phase (where present) as they occur in each length of growing period zone, in each major climate and in each country.

The first stage of the computer program records the extent an4 ·com­position of each map ping unit according to the listings given in the appropriate texts of the Soil Map of the World. These data are then sorted by countries and outprinted in the form of "turn around" documents for entry of the are as of each mapping unit by length of growing period zone and major climate as obtained from the grid co.unt.

The second stage of the program converts th is basic data input into extents of all individual soil units in each mapping unit, brok en down by slope and texture class and phase (where present), as they occur in each length of growing period zone and in each major climate at the country level.

The third and fin al stage of the land inventory sorts the component soil units of each mapping unit to provide total extents of each soil unit, categorized by texture class, slope class and phase (where present)

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as they occur in each major climate and in each length of growing period zone on a country basis.

Such is the land inventory available from the FAO study.

THE LAND SUITABILITY CLASSIFICATION

Comparison of the described attributes of land with crop require­ments provides an assessment of the suitability of land for the produc­tion of each crop of the study i.e. the crop specific land suitability classification.

Inherent in th is comparison is the generation of: a. an agro-climatic suitability classification, giving potential agronomic­

ally attainable crop yields in each length of growing period zone in each major climate suited to the growth of the crop and

b. a system of soil ratings showing how well the conditions of each soil unit match the soil requirements of each crop.

while it is not within the scope of the present paper to describe the synthesis of these items (full details in FAO, 197 8a) an understanding of their form is necessary as a pre-requisite to the description of the land classification system.

The agro-climatic suitability classification used in the study is derived in three steps, namely : (1) matching of the attributes of the major clinlates with the crop

adaptability groups. to determine which crops qualify for further consideration in the different major climates;

(2) calculation of net biomass and constraint-free yield potentialof all qualifying (in suitable major climates) crops in respect of the effect of the prevailing temperature and radiation regimes on crop photosynthesis and growth in the various lengths of growing period zones; and

(3) amendment of the constraint-free potential yields by reduction ratings reflecting yield losses th at occur due to agro-climatic con­straints, e.g. pests, diseases and weeds, according to their severity for each cropin each length of growing period zone and for each level of inputs.

The resulting agro-climatic suitability classification provides quantit­ative data on potential crop yields, with two levels of inputs circum­stances, in each length of growing period zone in eaeh major climate suited to the growth of the erop. Four suitability classes are employed, namely : very suitable, suitable, marginally suitable and not suitable.

The basis of these classes is a comparison of attainable erop yields in the different lengths of growing period zones, in terms of percent-

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ages of maximum attainable. If the yield of a crop fr om a particular zone is 80 percent or more of the maximum attainable, that zone is assessed as agro-climatically 'very suitable' (VS) for that crop. Zones with yields of 40 to less than 80 percent are classified as 'suitable' (S); 20 to less than 40 percent as 'marginally suitable' (MS); and less than 20 percent as 'not suitable' (N).

The system of soil ratings employed by the project shows the suit­ability of the soils inventoried for crop production and was compiled by matching the crops' soil requirements with the properties of the soil units. This resulted in the rating of all soil units for the production of the crop at two levels of inputs. The soil requirements for wheat and cassava (and other crops) are detailed in FAO (197 8a) and Sys and Riquier (1980). Modifications to the soil unit ratings, according to any significant limitations imposed by slope, texture and phase con­ditions, are also described in detail in the same volume.

The ratings are based on how far the soil conditions of a soil unit meet the crop requirements under a specified level of inputs. The appraisal is effected in three basic classes for each input level, i.e. very suitable or suitable (Sl), marginally suitable (S2) and unsuitable (N) . A rating of S 1 indicates that there are no, or only minor, soillimita­tions to the growth of the crop, provided climatic conditions are suit­able. The rating S2 indicates that soillimitations are such that they will adversely affect the growth of the crop but not to the extent of making the land unsuitable. A rating of N is given when the soillimit­ations are so severe that crop production is not possible or, at best, very limited.

Both the agro-climatic suitability classification and the soil ratings are necessary to arrive at the results of the study, namely the land suitability classification. This classification takes account of all the inventoried attributes of land and compares them with crop require­ments, to give an easily understood picture of the suitability of land for the production of the crop. F our land suitability classes are employed, each linked to anticipated yields for the two levels of in­puts considered. For each level of input, the land suitability classes (as for the agro-climatic suitability classes) are: very suitable - 80 percent or more of the maximum attainable yield; suitable - 40 to less than 80 percent of the maximum attainable yield; marginally suitable - 20 to less than 40 percent of the maximum; and not suitable - less than 20 percent.

The study thus provides concise data on the extents of land various­ly suited to the production of the crops of the assessment, under two

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levels of inputs, and the produetion potentialof these areas. In essenee, the suitability classifieation has been eompiled by

modifying the eomputed extents of lands in the four agro-climatie suitability classes by the ratings of the various soils inventoried in those areas, i.e. knowing the area of eaeh growing period zone, its agro­climatie suitability and the extent and degree of soillimitations to erop produetion, it is possible to eompute the areas of lands various-ly suited to the erop at eaeh of the two levels of inputs.

This is aehieved by applying the program illustrated in Fig. 1. Firstly the erop's photosynthesis and growth temperature require­ments are eompared with the prevailing temperature eonditions of eaeh major climate. If they do not aeeord, all the growing period zones in that major climate are classified as not suitable. If the tem perature eonditions of a major climate do aeeord with the erop's photosynthesis and growth temperature requirements, all the growing period zones in that major climate are eonsidered for further suitability assessment.

This further assessment, exeept for areas of Fluvisois, eomprises applieation of the agro-climatie suitability classifieation to the eom­puted areas of the various growing period zones. Thus, if a partieular growing period zone is agro-climatieally 'very suitable' (VS) for the produetion of the erop, then all areas of this growing period zone are classified, in the first instanee, as 'very suitable' from the agro-climatie viewpoint. If half the areas of a growing period zone are agro-climatie­ally 'very suitable' (VS) and half 'suitable' (S), then half of the extent of that growing period zone is eomputed as 'very suitable' and half as 'suitable' .

The next step is an appraisal of the soil units present in eaeh grow­ing period zone. The rating of the soil units, for the erop and level of inputs under eonsideration, is applied to the eomputed area of the growing period zone oeeu pied by eaeh soil unit (agro-eeologieal zone). This appraisal is undertaken on the basis of the soil ratings previously deseribed and leads to appropriate modifications of the agro-climatic suitability assessment. Subsequently, the ratings for different soil phases, soil slope and texture classes are applied eonseeutively to arrive at the finalland suitability appraisal for the erop, under one of the two levels of inputs.

An exeeption to this general methodology for the land suitability assessment is neeessary to deal with the particular eireumstanees of Fluvisols. The rules governing suitability on these soils are summarized in figure 1.

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Total extent

Major climate rules

All crops (except rice and cassava) : apply 55 percent 'suitable' for alllengths of growing period zones. For cassava : apply 20 percent as 'suitable' in alllengths of growing period zones in range of 240 to 120 days; remainder should be

Soil unit 'J' classified as 100 percent 'not suitable'. ~---------t For rice : apply 25 percent as 'suitable' in alllengths of growing

Length of growing period rules

Soil/phase rules

Slope rules

Fluvisols period zones except those in range of less than 75 days and more than 330 days which should be classified as 100 percent 'not suit­able'.

Symbols S1 = No change S2 = Decrease by one class N = Not suitable

Slope '~' lands: nl? change. Slope 'b' lands: (Low inputs) one-third 'not suitable'; one-

"" - third decrease by one class; one-third no change. {High in­puts) two-thirds 'not suitable'; one-third no change. Slope 'c' lands: 85 percent 'not suitable', 15 percent apply 'b' slope rules.

Texture '1?: decrease by one class except for some specified soil units which remain unchanged. Texture '2 & 3': no change.

(*) These tables and section numbers refer to material in FAO (1978a).

Fig. 1.

Agro-ecological Zone Data Base - Schematic Outline of the Land Suitability Assessment Program.

The methodology developed is scale neutral and can be applied to specific sites provided soil and climatic inputs are sufficiently quantit­ative for the scale of the investigation.

Results and conclusions

The results of the study are assessments of the extents of land (000 ha) variously suited to the rainfed production of each erop, by major climates and by lengths of growing period zones. Anticipated yields, from the four land suitability classes employed, are also given to enable calculation of production potentials by the two levels of inputs assumed in the assessment.

In the present paper such results are illustrated by the following summary data on the suitability of the lands in Africa for the produc­tion of rainfed cassava and wheat. In the computations, no account is taken of cultivation on residual moisture, fallow period requirements or of non-arable land requirements.

Table 4

Extents (000 ha) of land 'suitabie' to the production of rainfed cassava and wheat ' in Africa

Land Cla'ssification Very Suitable Marginally Not Suitable Suitable Suitable

a) Cassava Levels of inputs - high Extents (000 ha) 90035 148 289 137 547 2635459 Potential yields (t/ha) (1) 13.6-10.9 10.9-5.4 5.4-2.7 2.7-0.0 Total 'suitable' land 375871-

f- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --

Levels of inputs - low Extents (000 ha) - 37425 362498 2611407 Potential yields (t/ha) (1) 3.4-2.7 2.7-1.4 1.4-0.7 0.7-0.0 Total 'suitable' land 399923 -

b) Whéat Levels of inputs - high Extents (000 ha) 9716 17 397 8909 2975 308 Potential yields (t/ha) (2) 5.6-4.5 4.5-2.2 2.2-1.1 1.1-0.0 Total 'suitable' land 36022-

~--------------------------------------------

Levels of inputs - low Extents (000 ha) Potential yields (t/ha) (2) Total 'suitable' land

(1) Dry weight of tuber. (2) Dry weight of grain.

7332 1.4-1.1

16585 13771 2973642 1.1-0.6 0.6-0.3 0.3-0.0

37688-

Total

3011 330

r-------

3011 330

3011 330

-------

3011 330

162

In addition to providing data on the extent, location and potential of arable are as (question 2 and 3 of the introduction), the results of the study also furnish a basis for much of the information necessary to answer the questions postulated as pre-requisites to sound planning of optimum land use.

The question 'is there sufficient land to meet future food needs' ? can be answered by computing optimum calorie production from suit­able crops in each agro-ecological zone and comparing th is production with the calorie requirements of present and future populations in the zones. Such comparisons reveal critical areas where land resources are insufficient to meet the food needs of the populations presently (or projected to be) living on them. A study of this nature is already being carried out (FAO,1980a).

Other questions, suggested as necessary for planning purposes, can also be answered by the data generated by the study.

Areas giving maximum productivity returns from increased levels of inputs are located in areas of maximum suitability (very suitable) for each crop under consideration. In the case of rainfed cassava, the regions of maximum suitability are located in the 240-329 days lengths of growing period zones, where increases in productivity of the order of 8.2-10.2 t/ha (dry weight) may be expected through application of high levels of inputs. Equivalent increased inputs in less suitable areas, such as the 90-119 days length of growing period zone, are postulated to result in smaller productivity increments, i.e. 2.0-3.0 t/ha dry weight, because of moisture limitations.

Additionally, from the data generated by the study, limitations to production, and research priorities, can be identified together with the locations and extent to which they apply. Limitations to produc­tion, such as salinity, low infiltration rates, high phosphorus fixation, low water holding capacity, susceptibility to waterlogging, high rainfall variability, can be inferred from the soil units, major climates and lengths of growing periods used in the study. Perusal of soil unit/m.ajor climate/length of growing period extents reveals the total areas suffer­ing from such production limitations and allows formulation of re­search priorities to overcome them and so meet the most important needs of the region as a whoie.

The requirement for adequate land resource inventories (climate and soil), to meet such basic information needs of planners and research workers, is clear. It is hoped however that the present paper also em phasizes the necessity for an inter-disciplinary approach in such work, for resource inventories which cannot be matched to crop re-

163

quirements are of little use to planners. Equally important is the re­quirement to take all attributes of land (ineluding socio-economic circumstances) into account in determining land potential.

The descrihed methodology, applied by F AO's agro-ecological zone study, is one such study. It is scale neutral in concept. More detailed inputs, particularly on elimate (historical records) and soil, are how­ever necessary to achieve such studies at the project and nationallevel.

Some major needs which have emerged from the study are : - to define very clearly the land utilization types which will he con­

sidered, e.g. rainfed or irrigated cropping land; - to identify elearly and to record the characteristics of the cultivars

in the land utilization types being assessed, e.g. length of growth cyele, frost susceptibility;

- to take into account site specific interactive effects in lengths of growing period computations e.g. contrihution of snow melt, shedd­ing or receiving nature of site;

- to adjust (upgrade & downgrade) length of growing period computa­tions by soil and according to crop being assessed and, if necessary, carry over into dry-season temperature regimes, e.g. wheat on Vertisols in India;

- to take torrent watered . conditions into account, e.g. water sp reading from torrent flooding in Vemen;

- to effect separate and detailed climatic inventories in areas with contrasting temperature regimes, e.g. humid sub-tropics with two markedly contrasting seasons;

- to consider non-agricultural use requirements, e.g. national parks, built-on areas , and rest-period requirements.

LITERATURE

Dudal R., (1978) . Land resources for agricultural development. Proc. 11 th International congres of soil science. Vol. 2. Edmonton, Alberta : 314-340.

Food and Agriculture Organization of the United Nations, (1976). A framework for land evaluation. Soils Bulletin No. 32. Rome. 72 p.

Food and Agriculture Organization of the United Nations, (1969-1980). Soil Map of the World. Vois. I-X. Unesco, Paris.

Food and Agriculture Organization of the United Nations, (1978a). Report on the agro-ecological zones project, Vol. I : Methodology and results for Africa. World soil resources report No. 48/1. Rome. 158 p.

164

Food and Agriculture Organization of the United Nations, (197 8b). Report on the agro-ecological zones project, Vol. II : Results for Southwest Asia. World soil resources report No. 48/2. Rome. 28 p.

F ood and Agriculture Organization of the United Nations, (1979). Agriculture : Towards 2000. FAO twen tie th session conference document C 79/24. Rome. 257 p.

Food and Agriculture Organization of the United Nations, (1980a). Report on the second .FAO/UNFPA expert consultation on land resources for populations of the future. Rome. 369 p.

Food and Agriculture Organization of the United Nations, (1980b). Report on the agro-ecological zones project. Vol. IV : Results for Southeast Asia. World soil resources report No. 48/4. Rome. 59 p.

Frère M., (1976). Data held as agroclimatological summaries by Plant Production and Protection Division, Food and Agriculture organization of the United Nations, Rome.

Higgins G. M. & Kassam A. H., (1980). Ihe agro-ecological zone land inventory. Report on the second FAO/UNFPA expert consultation on land resources for populations of the future, Food and Agriculture Organization of the United Nations, Rome: 353-369.

Kassarn A. H., (1980a). Agro-climatic suitability and yields of rainfed crops of winter badey, upland rice, groundnut, sugarcane, banana/plantain, and oU palm. Report on the second FAO/UNFPA expert consultation on land resources for populations of the future, Food and Agriculture Organization of the United Nations, Rome: 97-121.

Kassarn A. H., (1980b). Multiple eropping and rainfed erop productivity in Africa. Report on the second .FAO/UNFPA expert consultation on land resources for populations of the future, Food and Agriculture Organization of the United Nations, Rome: 123-145.

Kassam A. H., Kowal J., & Sarraf S., (1977). Climatic adaptability of crops. Consultants' report, agro-ecological zones project. AGLS, Food and Agriculture Organization of the United Nations, Rome.

Sys C. & Riquier J., (1980). Ratings of FAO/Unesco soil units for specific erop production. Report on the second FAO/UNFPA expert consultation on land resources for populations of the future, Food and Agriculture Organization of the United Na­tions, Rome: 55-87.

Summary

The methodology used by FAO, to as se ss the potentialof the developing world's resources for the rainfed production of specific crops, is described and

165

the results are illustrated by consideration of the potentials for wheat and cassava production in Africa. The stud y is based on the 1: 5 million F AO/U nesco Soil Map of the World, upon which is superimposed a specially created climatic invent­ory matched to the climatic requirements of crops.

As an aid to the compilation of data on climatic requirements, crops are frrstly classified into climatic adaptability groups according to their photosynthesis and phenological characteristics. If temperature requirements for photosynthesis are met, the production potentialof a crop is then largely dependent on how weU its optimum growth cycle fits with the period when water is available for growth and development. Accordingly, the climatic inventory created by the study takes into account both heat (major climates) and moisture conditions (lengths of grow­ing periods) from which agronomically attainable potential crop yields are com­puted and classified. A total of 14 major climates and 211engths of growing period zones (30 day intervals) are inventoried.

Measurement of the unique soil/ climate units, resulting from the overlay of the climatic inventory on the soil map, provides quantification of the extents of each soil unit, sub-divided by slope class, texture class and phase (where present), as they occur in each major climate and in each length of growing period. The extents of these units (agro-ecological zones) are computed on a country by country basis.

Application of specific soil, slope, texture and phase constraints, to the agronomically attainable potential crop yield classification, provide the land suit­ability classification, i.e. the extents of lands variously suited to the production of each crop. Four land suitability classes are employed; very suitable, suitable, marginally suitable and not suitable with yield ranges for each of the 11 crops and two levels of inputs assessed.

The methodology, which uses most of the land evaluation principles and con­cepts developed by the FAO and Dutch inter-disciplinary land evaluation groups over the past ten years, is scale neutral and can be applied to any sized area with appropriate soil and climatic data inputs.

L'approche FAO pour la détermination du potentiel des terres par zones agro­écologiques

Résumé

La méthodologie utilisée par la FAO pour l'évaluation du potentiel de produc­tion pluviale des ressources en terres des pays en développement pour des cultures déterminées est décrite et illustrée par les résultats relatifs aux productions potentielles de froment et de manioc en Afrique. L'étude est basée sur la carte mondiale des sols (FAO/Unesco) à l'échelle du 1:5 000 000 sur laquelle on a surimposé un inventaire climatique spécialement créé en tenant compte des ex i­gences climatiques des cultures.

Pour faciliter la compilation des données sur leurs exigences climatiques, les cultures sont d'abord classées en groupes d'adaptabilité climatique suivant leurs caractéristiques de photosynthèse et de phénologie. Lorsque les exigences relatives à la température pour la photosynthèse sont satisfaites, la production potentielle d 'une culture dépend largement de la synchronisation entre son cycle

166

optimum de croissance et la période durant laquelle l'humidité du sol permet la croissance. C'est pourquoi, l'inventaire climatique créé pour cette étude tient compte de la température (dimats principaux) et des conditions d'humidité (du­rée de la période de croissance) et a été utilisé comme base de calcul et de dassifi­cation des rendements potentiels qui peuvent être atteints. Un total de 14 dimats prlncipaux et 21 durées de période de croissance (intervalles de 30 jours) sont inventoriés.

La mesure de la surface de chacune des unités so1/ dimat résultant de la surim­position de l'inventaire climatique sur la carte des sols permet de quantifier les surfaces de chaque unité pédologique subdivisée par dasse de pente, dasse de texture et par phase (si présenté) dans chaque climat principal et pour chaque durée de période de croissance. Les superficies de ces unités (zones agro-écolo­giques) sont calculées par pays.

L'introduction de limitations relatives aux caractéristiques des sols, à la pente, la texture et la phase, dans la classification des rendements potentiels agronomi­quement possibles conduit à la classification de l'aptitude des terres, et fournit les superficies de terres d'aptitudes différentes pour la production de chaque cul­ture. On utilise quatre classes d'aptitude (très apte, apte. marginalement apte et inapte) basées sur l'évaluation de la gamme des rendements de chacune des cul­tures à deux niveaux d'inputs.

La méthodologie utilise la plupart des principes et concepts d'évaluation éta­blis par la FAO et un groupe interdisciplinaire hollandais, au cours des dix der­nières années. Cette méthodologie est indépendante de l'échelle des études et peut être utilisée pour toute superficie ou existent des informations appropriées sur les sols et Ie dimat.

De FAO-benadering voor de bepaling van het bodempotentieel via agro-ecologische zones.

Samenvatting

De methodologie toegepast door de FAO om het produktievermogen te bepa­len voor specifieke niet geïrrigeerde gewassen in de gronden van de ontwikkelings­landen wordt beschreven en géillustreerd aan de hand van de resultaten bereikt voor tarwe en maniok in Afrika. De studie is gebaseerd op de FAO-UNESCO bo­demkaart van de wereld (schaal 1/5.000.000), gecombineerd met de klimaatsin­ventaris waarin de vereisten van de gewassen zijn opgenomen.

Om de compilatie van de gegevens over deze klimaatsvereisten te vergemakke­lijken werden de kulturen eerst onderverdeeld in groepen in funktie van hun fotosynthetische en fenologische eigenschappen. Ais aan de temperatuursvereis­ten voor de fotosynthese is voldaan is het produktiepotentieel van een gewas in grote mate afhankelijk van het synchroon verloop tussen de optimale groeicyClus en de periode met voldoende grondvochtigheid. Om die redenen houdt de kli­maatsinventaris die voor deze studie is gemaakt zowel rekening met de tempera­tuur (hoofdklimaten) als met de vochtomstandigheden (duur van de groeiperiode). Tevens kan deze inventaris gebruikt worden als berekenings- en dassificatiebasis voor de mogelijk te bereiken potentiële opbrengsten. In totaal werden aldus 14 hoofdklimaten en 21 in duur verschillende groeiseizoenen (met 30 dagen interv·al)

167

geïnventariseerd. De opmeting van de oppervlakte van elk van deze bodem/klimaatseenheden -

bepaald op grond van een combinatie van de klimaatsinventaris en de bodemkaart -laat toe het belang van elke bodemeenheid te kwantificeren. Daarnaast kan te­vens een onderverdeling gemaakt worden in textuur- en hellingklassen of eventueel in fasen binnen elk hoofdklimaat en voor om het even welk lang groeiseizoen (met 30 dagen interval). De oppervlaktes van deze eenheden (agro-ecologische zones) worden berekend per land.

De invoering van bodem-, helling-, textuur- of faselimitaties met het oog op de classificatie van de potentiële landbouwopbrengsten laat toe de oppervlaktes te evalueren van de gronden met verschillende produktiecapaciteit voor elk gewas. Vier geschiktheidsklassen zijn gebruikt (zeer geschikt, geschikt, marginaal ge­schikt, en ongeschikt) waarbij rekening werd gehouden met de mogelijke opbreng­sten voor elk van de 11 gewassen verbouwd op twee kultuurniveau's.

Deze methode past grotendeels de principes en het concept toe die werden opgesteld door de F AD en de Nederlandse interdisciplinaire werkgroep gedurende de voorbije tien jaar. Ze is daarenboven niet gebonden aan de schaal van de stu­dies en kan gebruikt worden voor elk gebied waar voldoende bodem- en klimaats­gegevens beschikbaar zijn.

168

PEDOLOGIE, XXXI, 2, p. 169-190,12 tab., 9 fig. Ghent, 1981

EV ALUATION OF SOIL AND LANDSCAPE CRITE­RIA WITH RESPECT TO LAND-USE POTENTlALS IN EUROPE.

C.SYS

1. Introduction

The working party on Soil Classification and Survey of the Europ­ean Commission on Agriculture held its ninth and last session in Ghent in September 1973. It was then officially dissolved in accordance with a decision of the Executive Committee which considered that the main task of the Working Party, i.e. the compilation of the Soil Map of Europe, was practically completed and decided that any new activities should be carried out through ad hoc Working Parties.

Accordingly, it was recommended that an ad hoc Consultation of experts would meet in 1975 in order to develop methods and criteria adapted to European conditions.

At present a soil map of the European Community is in compila­tion. This map makes available a series of information. We may assume that this· information, together with the existing climatic data, could be used for a practical evaluation of the factors of the physical environ­ment. I do not yet use the term "Land Evaluation" because land eva­luation implies not only a systematic interpretation of the physical factors, but also a socio-economic analysis of the environment. Such an overall evaluation is required as background information in agri­cultural, industrial and urban extension planning.

Under European conditions, such interpretations are most likely to be made in view of an intensive use of the land; they will further help in environmental conservation.

In the next future it is necessary to study the possibilities for the introduction of uniform standards for physicalland evaluation in the different countries of the conlmunity and to examine how far the principles outlined in the "FAO Framework for Land Evaluation"

Sys C. - Prof. Tropical Soils and Land evaluation, State University Ghent, Krijgs­laan 271, 9000 Ghent, Belgium.

169

could be used or adapted to European conditions.

2. General evaluation or evaluation for a specific use

At present most systems of land evaluation deal with interpretative classifications. They present an evaluation in different categories, each corresponding to a certain level of detail. At each level the interpreta­tion differs in precision, objectives, requirements and assumptions. These successive steps may help the user in a better understanding of the system.

The "FAO Framework for Land Evaluation" made a difference between actual and potential suitability classifications. Actual suit­ability classification is related to the present condition of the land and is based on direct observations; potential suitability classification re­flects a future situation, af ter the land has been changed by major land improvements.

Most land classification systems used in Europe are set up for agri­cultural use with a moderate to high level of management. Most of ten improvements at acceptable costs are included. This means that these classifications are actual.

Looking to the main structure and objectives of different land classification systems a subdivision into two main groups can be made.

A first group includes systems of general appraisal not related to a specific use. The USDA-system of land capability classification is the most typical example of this group. However, notwithstanding the general appraisal approach, the preferential utilization type and land­use is reflected in the classes. Classes 1 to 4 have a preferen tial use for arabie land; class 5 for pasture; classes 6-7-8 for pasture and/or forest.

Exam pIes of classification systems in Europe derived from the USDA scheme but adapted to local conditions are the Land Use Capability Classification of England, Wales and Scotland (Bibby & Mackney, 1969), the Land Evaluation of Ireland (Gardiner, 1974) and the Land Capability System of Portugal (Carvalho Cardoso, 1968).

The second approach is to achieve an eValuation for specific use. The land classification in Western Germany (Bödenschätzung) (Roth­kegel, 1952; Reichel, 1973) makes an evaluation for selected land, grassland, horticulture, vineyards, etc. A regionalland suitability classific~tion developped in France (dept Oise) (Begon et Remy, not published) makes an evaluation for arabie land with 4 local crops : sugar heets, maize, small grains and potatoes.

Also the "FAO Framework for Land Evaluation" recommends an

170

evaluation system for specific use; from there the definition of the concept "land utilization type" defined by the crop(s) and the manage­ment.

3. Quantitative or qualitative evaluation

A distinction is made between qualitative and quantitative classific­ations. Quantitative systems are reserved to inform the user that the interpretative groupings are defined in precise numerical economic terms. Classifications which do not meet this requirement would be described as qualitative, although they may be based on varying amounts of quantitative data on yields and required inputs.

The choice between a qualitative and quantitative evaluation will depend on the level of generalization and on the availability of data related to the socio-economic aspects.

A qualitative approach appears to be the only practical method when interpretation of small-scale maps is concerned. At this high level of generalization it is difficult torgeneralize the results of economic investigations often obtained at farm level.

The diversity in product ion costs may indeed greatly depend from farm to farm and is particularly related to the size and the structure of the farm (farming system). In this respect an analysis of the cost price of wheat in North Belgium was made in the 1960's, as the inputs dep end mostlyon the size of the farm. The farms were divided into three categories (Sys, 1969) (tables 1-2). - large farms, more than 40 ha : dominance of arabie land and less

than 15 % of the surface is under grassland, fully mechanized; - medium farms, 20-40 ha : in general 20-25 % of the surface is under

grassland, partially mechanized; - small farms, 8-20 ha : 25-45 % is under grassland, dominance of

family labour and animal (horse) traction.

The difference in cost price between non drained and artificially drained land is due to the amortization and maintenance of the drain­age system.

Suitable orders and classes could be defined in economic terms as follows.

Order S : suitable, giving a production of more than 35 % of the optimal yield and providing a net benefit : - class SI : yield above 90 % of optimal yield; net benefit more than

75 % of optimal; - class S2 : yield 60 to 90 % of optimal yield; net benefit between

25 and 75 % of optimal;

171

Table 1

On-farm cost price of wheat in northern Belgium (C. Sys, 1969)

Size of farm Cost price in kg of wheat per ha

non drained land artificially drained land

Large 2812 3021 Medium 3074 3282 Small 3650 3830

Table 2

Hours of labour and farmpower per ha on different size farms

Size of farm Hours of labour/ha Percent of

Family labour Paid labour Horse power Tractor production costs

Large 8.5 18 0 18.5 31 Medium 26 28 18 12 39 Small 160 18 95 4 48

Table 3

Relative importance of different inputs with regard to farm size

Type of input Relative inputs in percent of production costs

Large farm Medium farm Small farm

Drained Non Drained Non Drained Non drained drained drained

Labour and farmpower: 31 32.9 39 42 48 51.2

F ertilizers 9.4 14.9 13 13.7 10.9 11.5

Seed 10.6 11.4 9.8 10.4 8.6 8.8 Amortization investment 14.1 14.8 9.9 10.2 8.1 8.5

Amortization of drainage 6.9 - 6.3 - 5.4 -

Rent 24 26 22 23.7 19 20

172

- class S3 : yield 35 to 60 % of optimal yield; net benefit less than 25 % of optimal.

Order N : non suitable, giving a production of less than 35 % of op­timal yield and providing no net benefit : - class NI : N-land that can be improved; - class N2 : N-land that cannot be improved.

This quantitative classification can be applied successfully for individual crops, within a farm unit as is illustrated in table 4.

Table 4

Evaluation of soil types for wheat on three representative farms in Northern Belgium

Farm Soil Yield Percent of Net Percent of Land location series (1) kg/ha optimal benefit optimal class

yield kg/ha benefit

Langemark Lee 4762 79 1688 58 S2 Ldedr 4886 81 1604 58 S2 Lepdr 4150 69 868 32 S2 Pee 4066 67 992 34 S2 Eep 3375 56 301 10 S3

Ingooigem Sbe 3850 64 200 9 S3 Sec 4290 72 640 27 S2 Pee 4732 79 1082 46 S2 Ldedr 5058 84 1198 55 S2

Gottem Sba 3850 64 200 9 S3 Pba 4965 82 1 315 56 S2 Pee 5225 87 1 575 67 S2

(1) Soil series classifieation aeeording to the Belgian system (R. Tavernier et al., 1960)

When eomparing different farms, difficulties may arise in the inter­pretation for a single erop. Moreover, in the ease of a mixed farm with a complex strueture, where part or all of the produce is valorized through cattle-breeding, the interpretation becomes very difficuit and has to be based on estimates.

The same soils, situated on the same farms were further evaluated aeeording to a qualitative system and a land indice was ealculated aceording to therequirements of table 5.

For this qualitative evaluation the classes were defined in terms of intensity and number of limitations as follows.

Order S : suitable land : land units with only moderate, sligh t or no

173

Table 5

Evaluation of physicalland characteristics for wheat in Northern Belgium

Land characteristics Range in the degree of the limitation

0 1 2 3 4

TOPOGRAPHY (t) 0-2 2-8 8-16 16-30 30+ (slope %) (100) (95 ) (80) (50) (30)

CHARACTERISTICS AT THE ORIGIN OF WETNESS LIMITATIONS (w) Drainage 1) well moderate imperfect po or gr. w. very poor

(100) (90) (80) (45) (dr.60) (20) (dr. 85) poor excessive

pseudogley (20) (50) (dr. 70)

2) imperfect moderate weIl (100) (90) (70) id. as 1)

Flooding no - - slight others (100) (50) (20)

CHARACTERISTICS WITH REGARD TO PHYSICAL SOILS CONDITIONS (s)

Texture 3 A (95) L (85) P (75) S (60) -

ECaCOJ ( 100) E (80) Z (45) Stoniness -5% 5-15% 15-40 40-80 +80

(100) (90) (80) (60) (25) Depth (cm) +120 80-120 50-80 20-50 -20

(100) (90) (75) (55 ) (30)

CHARACTERISTICS WITH REGARD TO FERTILITY NOT EASIL Y CORRECTED(f)

Profile development non podzols podzols - - -

(100) (85) Base saturation all soils are high, so not evaluated Organic matter (%) +1.5 1-1.5 0.8-1 -0.8 -

(0-15 cm)

1) Drainage : medium- and fine-textured soils (textural symbols L, A, E, U) 2) Drainage: coarse-textured soils (textural symbols P, S, Z) 3) Texture : according to Belgian classification

limitations and no more than one severe limitation that, however, does not exclude the use of the land; suitability index more than 25 : - class SI: land units without or with only 3-4 slight limitations;

land coefficient +75; - class S2 : land units with more than 3-4 slight limitations and no

more than 2 moderate limitations; land coefficient from 50 to 75; - class S3 : land units with more than 2 mcderate limitations and/or

one severe limitation that, however, does not exclude the use of the land; land coefficient from 25 to 50.

174

I--" -....J U1

Table 6

Evaluation of soil types for wheat aeeording to physiealland conditions

Situation Soil T opo- Charaeteristics at Charaeteristics with regard Charaeterlsties with Land Land of farm series graphy origin of wetness to physical soil conditions regard to natural fertility eoeffi- class

(t) (w) (s) (f) cient

Drainage Flooding Texture Depth Stonin. ProfIle Base Org. devel. saturat. matter

Langemark Lee 0(100) 1(90) 0(100) 1(85) 0(100) 0(100) 0(100) 0(100) 0(100) 77 Si Ldedr 0(100) 2(85) 0(100) 1(85) 0(100) 0(100) 0(100) 0(100) 0(100) 72 S2w Lepdr 0(100) 2(60) 0(100) 1(85) 0(100) 0(100) 0(100) 0(100) 0(100) 51 S2 Pee 0(100' 1(90) 0(100) 2(75) 0(100) 0(100) 0(100) 0(100) 0(100) 68 S2s Eep 0(100) 3(45) 0(100) 2(80) 0(100) 0(100) 0(100) 0(100) 0(100) 36 S3w

Ingooigem Sbe 0(100) 2(70) 0(100) 3(60) 0(100) 0(100) 0(100) 0(100) 0(100) 42 S3s Sec 0(100) 1(90) 0(100) 2(60) 0(100) 0(100) 0(100) 0(100) 0(100) 54 S2s Pee 0(100) 1(90) 0(100) 2(75) 0(100) 0(100) 0(100) 0(100) 0(100) 68 S2s Ldedr 0(100) 2(85) 0(100) 1(85) 0(100) 0(100) 0(100) 0(100) 0(100) 72 S2w

Gottem Sba 0(100) 2(70) 0(200) 3(60) 0(100) 0(100) 0(100) 0(100) 0(100) 42 S3s Pba 0(100) 2(70) 0(100) 2(75) 0(100) 0(100) 0(100) 0(100) 0(100) 53 S2s

L _________ Pee __ 0(100) 1(90) 0(100) 2(75) 0(100) 0(100) __ ~_POO) _0~~~_O(100) _~~ ___ ~2s __

Y Kg/ha Fig. 1. 5000

Relation hetween the soil 4.750 indice (x) and main yield

(y) for Langemark 4500

4250

LOOO Y : .22785316.32496.

, : 0.9020

3.750

3.500

3250

3~ lIJ 45 50 S5 60 65 70 75 80-

y Kg/ha Fig. 2. 1700

1600 Relation hetween the soil 1500 indice (x) and net henefit 1400

(y) for Langemark 1300

1200

1100

Kloo

900 y: . 858 7148 • 32 167x

800 r : 09502

700

600

500

LOO

300

--rs t.O 45 sa 55 60 65 ia 7'5 80'

Y Kg/ha Fig. 3. 5100

Relation between the soil 5000

indice (x) and main yield 4900

1.800 (y) for Ingooigem

4700

4600

L500

411J0

4300 Y' 2239.4541. 38.0111

, • 0.9907

420

4100

IIJOO

:J9OO

3100

3700 50 55 65 10.

176

Kg/ha

900

~o

700

600

500

400

)JO

200 50

Y Kg/ha 525

5000

4750

4500

4250

3750

40 45 50

Y Kg/ha

1600

1400

1200

1000

800

600

400

200

40 4S 50

Y' -1177.4619.33.177.

r = 0 .9991

ss 60

'Y = 1797.780 .Sl .l7&.

r • 0.9156

65

Soil coetllcilnt 55 eo 65.

,. -1852.292 .53376.

r. 0.9156

a.

70.

Fig. 4.

Relation between. the soil indice (x) and net benefit (y) for Ingooigem.

Fig. 5.

Relation between the soil indice (x) and main yield (y) for Gottem.

Fig. 6. Relation between the soil indice (x) and net benefit (y) for Gottem.

177

Kg/ho Fig. 7. 5200 Relation between the soil 5100 indice (x) and yield (y) 5000 from different farms 4900

4800

4700

4600

4soa

4400

4300 y : 3715.6528 • 15 943 x

4200 r : 0.6439

4100

4:lOO

3900

30 lIJ SO 60 70 80 90.

Y Kg/ ha Fig.8.

3

2800 Relation between the soil

2600 indice (x) and net benefit

2400 (y) from different farms

2200

2000

ISOO

1600

1400

1200

1000 Y : 31 6741 • 22 171.

800 r : Q.634S

600

400

30 40 SO 60 70 80 90 x

Y KIl/1>a Fig. 9. 2100 Relation between the soil 1900 indice (x) and net benefit

1700 (y) from farms with a similar management.

1500

1300

Y : -632 .7886 • 30.716.

\100 f. (l.8785

900

700

500

300

30 40 50 60 70 80 90.

178

Order N : unsuitable land : land units with one or more severe limit­ations which exclude the use of the land or with one or more very severe limitations; soil coefficient Ie ss than 25 : - class NI : land units with severe or very severe limitations that can

be corrected; - class N2 : land units with severe or very severe limitations that can­

not be corrected.

The soil series mentionned in table 4 were evaluated quantitatively in table 6. Comparison of tables 4 and 6 indicated that at the end of the exercise there was a comparable classification of the land units.

Studying the relation between qualitative and quantitative classific­ation Sys (1974) pointed out th at the land indice calculated from soil characteristics was highly correlated with the yields and net benefits at farm level (fig. 1 to 6). If all farms,each of them with their particular structure, were studied together the overall correlation was poor (fig. 7 -8). However a regroupment of farms according to farm size classes revealed again a better correlation between the soil indice and the yields (fig. 9);

From these informations we could assume th at a quantitative evaluation finds its best application at farm level. The relation studied between land characteristics and economic factors can however be generalized to support the qualitative evaluation at a more generalized level.

Qualitative evaluation, with socio-economic conditions in mind, will probably be the most common form of evaluation. It has to be based on the interpretation of land characteristics or land qualities.

4. Land characteristics or land qualities

Land characteristics are measurable properties of the physical environment directly related to land use. The land characteristics made available af ter a soil survey (and therefore to be used for evaluation) are: - climate (c) - topography (t) - wetness (w) :

- drainage - flooding

- physical soil characteristics : - texture (including stoniness) - soil depth - depth and intensity of acid sulphate layer

179

- calcium carbonate content - gypsum content

- fertility characteristics not readily to be corrected : - cation exchange capacity of the day fraction as an expression of

the weathering stage - base saturation - organic matter content

- salinity and alkalinity - salinity status - alkalinity status.

As land characteristics have to be considered in terms of limited interpretations because of their specific interaction there is a clear tendency to replace the characteristics by land qualities particularly when the extra soil resources are considered.

Land qualities are measurable, calculable or estimable attributes, representing the immediate requirements of the land utilization types. They are in fact practical consequences of land characteristics.

At the highest level of generalization three "comprehensive land qualities" have been suggested, each with a distinct influence on the suitability of land for a specific use; they are : - gross productivity (yield of produce and other benefits), - required recurrent (management) inputs, - non-recurrent (improvement) inputs, wh ere relevant.

Each of these "high level comprehensive qualities" is the result of the interaction of less complex single land qualities of which the most important are:

Internal qualities : - water availability - oxygen availability - availability of foothold for roots - nutrients availability - absence of salinity and alkalinity.

External qualities: - correct tem perature regime - resistance against erosion - ability for lay-out for farm planning - workability.

A more detailed list of land qualities, related to a specific use has been made by Brinkham & Smith (1973).

The major land quality "available water" for example is related to

180

1--0> 00 1--0>

Table 7

Relation between land characteristics and land qualities

Internal qualities Characteristics

Climate Water availability -.;;:;;;::::::~=--=----====================-;Topography

Oxigen availability

Wetness - drainage - flooding

External qualities

Correct temperature regime Resistance against erosion

Ability for lay-out of farmplan Physical soil characteristics - texture/structure / - stoniness ======================Workability

Availability of foothold for roots ,/ ====------ - depth - CaC03 status - gypsum status

Nutrients availability Fertility characteristics ~- apparent CEC ---------==== - base s~turation

- orgaruc matter Absence of salinity and alkalinity . Salinity and alkalinity

the following characteristics : - dirnatic characteristics

- arnount of precipitation - evapotranspiration

- soil characteristics - water retention capacity

b'l' } both related to texture and structure

- permea 1 lty - depth of the soil - nature of day minerals - drainage, induding position of groundwater.

The relation between texture and available soil water is known in general terms. Available water expressed in cm. of water per meter of soil may vary from 5 cm. for a sand to 20 cm. for a day loam, silty day loam and silty day.

Permeability is very rapid for sand (+ 12 cm,fhour) but is slow for fine-textured soils (0.1-0.5 cm,fhour); massive days have permeabilities of even less than 0.1 cm.

Soils with allophane may have a high water retention but because a great part of that water is retained at high tensions they may have only few available water even for fine textures. As su eh some fine­textured soils on volcanic ash present an available water content of 0.7 to 1 inch per foot of soil, where texture should predict a content of 1.6-2 inches.

It is dear th at the depth of the soil over an indurated horizon will not only determine the availability of foothold for roots but also the amount of water that a soil can store.

For a same textural dass the available water is also related to day mineralogy. Soils dominated by 2/1 days, particularly smectites, have a higher water storage capacity than soils with kaolinitic days and iron oxides.

I t is suggested to determine available water according to the rela­tion:

W.A. = (ETc-D)100 ETc

WA = water availability in percent ETc = erop evapotranspiration D = deficit of water comparing ETc and effective rainfall.

The qualitiy of "nutrient availability" depends, for so far natural fertility is concerned, mainly on following land characteristics : - cation exchange capacity . - base saturation - organic matter content.

182

These characteristics are normally furnished by the analytical data provided to define the physico-chemical properties of the soil series.

Expressed in more chemical terms of nitrogen, phosphorus, bases and even trace elements, the quality "availability of nutrients" has for a long time been the main concern of soil fertility specialists. F or an optimal evaluation the different nutrition levels should be established for the different nutrients and for the speciflc land utilization types. In the present conditions this information is mostly not available and one can only refer to the physico-chemical characteristics reflecting the natural fertility as indicated above.

The "availability of oxygen for plant roots" is related to soil structural conditions and to excess of water.

Lack of structural stability of the topsoil may re sult in a very low macro-porosity, particularly in irrigated farming, leading to condi­tions of poor aeration af ter irrigation or after a heavy rain in rainfed agriculture.

Excess water drives the air from the soil pores and leads to a lack of oxygen. This can best be evaluated by a determination of the degree of excessive wetness.

The land quality "availability of foothold for roots" can be evaluated with regard to the characteristics soil depth and excess water (drain­age). Deep well drained soils have no limitations for this quality; shallow or very poorly drained soils have severe limitations.

The conditions for germination are determined by the availability of water at the time of sowing and by the structure of the topsoil. This topsoil structure depends in most cases on the soil structure in relation to tillage operations and is often determined by the water con ten t at tillage.

Salinization and alkalinization are in fact land characteristics and there is abundant literature on the influence of salinization and alkal­inization of soils in relation to plant growth. The interpretation of these characteristics is one of the main concerns in judging actual and potentialland uses and possible improvements in the more arid and semi-arid regions.

Soil toxicity or extreme acidity are properties mainly occurring in troJ?ical regions where Al and Mn toxicity may occur; Mn levels of more than 200 ppm. are common on highly weathered soils on basic rocks. Extreme acid conditions may appear af ter drainage of potential­ly acid sulphate soils.

The other physicalland qualities are related to external soilland characteristics (climate, topography, flooding).

183

According to the available data an evaluation based on character­istics or qualities has to be selected.

5. Interpretation of present land-use as a parameter for land evaluation

Sys (1969, 1975) has drawn the attention on the relation between preferential use of the soil by the farmer and its suitability for a specific erop.

This is illustrated for wheat in tables 8 and 9.

Table 8

Distribution of the wheat growing area in function of soil texture in N-Belgium

Texture (1) Distribution of textural class (%)

% wheat per textural class

Clay 2.72 13.22 Loam 24.55 29.43 Sand loam 22.58 24.15 Light sandy loam 26.56 18.76 Loamy sand 11.67 18.57

(1) According to Belgian textural diagramme (R. Tavernier et al. 1960).

Table 9

Distribution of the wheat growing area in relation to drainage classes on the fine and medium textured soils in N-Belgium

Drainage class Distribution of the % wheat per drainage class ( %) drainage class

Well drained 2.38 32.82 Moderately weil drained 35.33 26.73 Imperfectly drained ( artificiall y drained) 44.19 25.34 Poorly drained (artificial drainage) 18.10 3.82

Other soil characteristics were studied for several crops and it was found that in an old cultivated landscape, preferentialland-use reflects the experience of the farmers and could help in selecting correct ratings for the individual soil characteristics.

6. Advantage of the study of erop requirements

Evaluation is difficult and remains empirie if we do not know the

184

Table 10

Climatic erop requirements for sugar eane

Land eharaeteristies

CLIMATE (c) Mean day temp.

germination stage (o~)

Mean day temp. for tillage stage (oC)

Mean day temp. veget. stage (oC)

t:, (*) maturation stage

Radiation, sunshine (hours/year)

Mean annual n/N

Relative humidity % in: vegetat. stage maturation stage

Rainfall (mm) in 10 days period

t:, = T max. - T min. Tmean

o

26-30

27

25-27

+0.5

+2,200

+0.50

+70 -60

+70

Degree of limitation

1 2

30-32 32-34 26-24 24-20

28-30 30-32 26-24 24-20

25-23 23-22 27-30 30-32

0.45 0.40

1,800- 1,800-2,200 1,400

0.4-0.5 0.3-0.4

70-60 60-50 60-70 +70

60-70 50-60

3 4.

34-35 +35 20-16 -16

32-35 +35 20-16 -16

22-20 -20 32-35 +35

0.35 -0.35

1,400- -1,200 1,200

0.25-0.3 -0.25

-50

-50

requirements of the crops. Therefore it is most likely to study, for each land utilization type the requirements in terms of land character­istics or land qualities.

Optimal and marginal conditions have to be suggested. However the relative evaluation can be realized in several degrees of limitation (limitation levels). For our purpose we use a five level scale, where the "severe" level is used when the property is very marginal. These different levels in the degree of limitation are defined as follows : - no limitations (0) : the characteristic (quality) is optimal for plant

growth; - slight limitation (1) : the characteristic (quality) is nearly optimal,

and affects productivity for not more than 20 percent with regard to optimal yield;

- moderate limitation (2) : the characteristic (quality) has a moderate

185

Table 11

Landscape and soil crop requirements for sugar cane

Land characteristics Degree of limitation

0 1 2 3 4

TOPOGRAPHY (t) (1) 0-1 1-2 2-4 4-6 +6 (2) 1-3 0-1 8-12 12-16 +16

3-8 (3) 0-3 3-8 8-16 16-25 +25

WETNESS (w) Flooding Fo F1 F2 F3,F4 Drainage (4) good moderate imperfect po or, poor

aeric typic very poor..

(5) imperfect moderate good poor poor aeric typic

very po or

PHYSICAL SOIL CHARACTERISTICS (s) Texture/ CL, SiCL, SC, L, SCL, SL, LSf, LSc,Sf Sm,Sc

structure Si, SiL, C+60s Cm, SiCm SiCs, C-60, s, Co

Surface stoniness (2) -3% any 3-15% .. G-S 3-15% R 15-40% R +40% R 3-15 % g 15-40% g 15-40% G-S 40-75% G-S +75% G-S

40-75% g +75% g (3) -3% R 3-15 % R 15-40% R 40-75% R +75% R

-15% G-S 15-40% G-S 40-75% G-S +75% G-S -40% g 40-75 % g +75%g

Subsoil stoniness +15% at 15-40% 40-75% any depth within within

50 cm 50 cm -15-40% 40-75% between between 50-80 cm 50-80 cm 40-75% between 80-120 cm

Depth (cm) +120 cm 80-120 50-80 25,.50 -25 CaC03 (%) (6) 0-12 12-25 25-35 35-50 +50 Gypsum (%) (6) 0-3 3-6 6-12 12-20 +20

186

FERTILITY CHARACTERISTICS (f) Apparent CEC

+24 16-24 -16 subsoil (meq/100 g)

Base saturation B +50 (--charge~

~ B any --+

( %) A . .. 80 A 50-80 A 35-50 Organic

carbon (7) '1-2.5 1.5-2.5 (% C, 0-15 cm)

(8) +1.5 1-1.5 (9) +0.8 004-0.8

SALINITY AND ALKALINITY (n) Conductivity . (mmhqs/cl}l) 0-2 2-5 Na-saturation 0-5 5-10

(1) Irrigated agriculture (2) Mechanized farming

1.0-1.5

0.6-1 -004

5-8 10:'15

(3) Low level of management without mechanization ( 4) Fine and medium textured soils ( 5) Coarse textured soils (LS - S - S L ) \1) Kaolinite materials (8) Non kaolinite, non calcareous materials (9) Calcareous materials.

-16 ( +charge)

A-35

-1.0

-0.6

8-10 15-20

+10 +20

influence on yield decrease; however, henefit can still he made and use of the land remains profitahle;

- severe limitation (3) : the characteristic (quality) has such an in­fluence on productivity th at the use hecomes marginal;

- very severe (4) : such limitations will not only decrease the yield helow the profitahle level hut may even totally inhihit the use of the land.

The erop requirements, as wen for climate, landscape and soil can he represented in a scheme, illustrated for sugar cane in tahles 10, 11 and 12.

7. Conclusions

The choice of a methodology in land evaluation requires an answer on the questions formulated ahove.

when a choice has heen made hetween the different alternatives it hecomes possihle to develop a working method and to suggest de fini­tions of classes and sub-classes formulated (1) in economie terms when a quantitative evaluation is selected or (2) according to the numher and intensity of limitations of characteristics or qualities when a qualitative evaluation has to he done.

187

f-l 00 00

Table :12

Crop requirements for sugar cane under mechanized plantation farming without irrigation

Land qualities Range in degree of intensity of lirnitations

0 1 2 3 4 no slight moderate severe very severe

Water availability- +90 80-90 65-80 55-65 -55 % of annual ET c (100) (90) (75) (55) (40)

r------------------------------------------- ----------------------------------Oxygen weU drained moderately irnperfectly poorly drained poorly drained availability macroporos. drained and drained and macroporos. and/ or

+25% macroporos. macroporos. +10% macroporos. (100) +20% +15% or better drained -10%

or weU drained or better drained and macroporos. (45) and macroporos. and macroporos. 10-15 % 20-25% 15-20% (60) (90) (75)

r -------------- ---------------------------------------------------------------Nutrients pH:6.6-7 7-8.5 8.5-9 +9 -4 availability 6-6.5 5.2-6 4.0-5.2

or. matter: +3% 1.5-3 0.8-1.5 -0.8 Ca:+10 5-10 2.5-5 -2.5 K:+0.85 0.5-0.85 0.3-0.5 -0.3 P205:+20 ppm 12-20 6-12 -6 CEC:+16 12-16 8-12 4-8 -4 (100) (90) (75) (55) (45)

r -----------------------------------------------------------------------------Availability foot- +100 80-100 50-80 25-50 -25 hold for roots (cm) (100) (90) (75) (50) (30)

r-----------------------------------------------------------------------------Workability very good good moderate poor very bad

(100) (90) (75) (50) (25) ~-----------------------------------------------------------------------------

Ability for lay-out +500 ha 300-500 ha 100-300 ha 50-100 ha -50 ha by farm plan (100) (90) (80) (60) (40)

REFERENCES

Bibby & Makney, (1969). Land use capability classification. The Soil Survey Technical Monograph, n° 1.

Carvalho Cardoso, (1968). Soil Survey and land-use planning in Portugal. Transact. 9th Int. Gongr. Soil Sci. Australia, IV, 261-269.

FAO, (1976). A framework for land evaluation. Soils Bull. 32, FAO, Rome, 120 p.

Gardiner M. J., (1974). Land evaluation studies in Ireland, in Approaches to Land Classification. Soils Bull. 22, FAO, Rome: 96-102.

Reichel H., (1973). Uberprüfung der Ergebnissen der Reichsbodemschätzung auf ihren ökonomischen Aussagewert unter heutigen Produktionsbedingungen. Hohenheim.

Rothkegel W., (1952). Landwirtschaftliche Schätzungslehre. Stuttgart.

Sys C., (1969). Bijdrage tot de studie van bodemgeschiktheid voor tarwe. Centrum voor Bodemkartering, Gent, 24 p.

Sys c., (1975). Guidelines for the interpretation of landproperties for some generalland utiliza­tion types. Soils Bulletin 29 - Land evaluation in Europe, FAO, Rome: 107-118.

Sys C., (1978). The outlook for the practical application of land evaluation in developed countries. World Soil Resources Report n° 49, FAO, Rome: 97-111.

Tavernier R., Marechal R. & Ameryckx J., (1960). Bodemkartering en bodemklassificatie in België. Monografie van bodem en water in België. Ministerie van Landbouw, National Comité van de FAO, 55 p.

Summary

The systems of land evaluation can be subdivided into two main groups : systems of general appraisal and systems where evaluation is done for a specific use. A choice has to be made between both.

A comparative study of quantitative and qualitative evaluation for wheat is illustrated for Belgium. This indicates good relationships at farm level; however poor correlation between soil indice at one hand, yield and net benefit at the other hand are noted when management type present too many variation.

Attention is drawn on the fact that a choice should be made between an evalua-

189

tion according to land characteristics or an evaluation based on land qualities. The study of land-use as a parameter for land evaluation is illustrated. It is further stated th at the basic work should be oriented on the study of cr op

requirements to be expressed in terms of land characteristics and/or lane! qualities.

Evaluatie van bodemkundige en topografische kenmerken in verband met het bodemgebruikspotentieel in Europa

Samenvatting

De landevaluatiesystemen kunnen in twee groepen onderverdeeld worden : algemene evaluatie en evaluatie voor een specifiek gebruikstype. Bij de aanvang van een studie dient in verband hiermee een keuze gemaakt te worden.

Een vergelijkende studie tussen kwalitatieve en kwantitatieve evaluatie toont aan dat een duidelijke correlatie bestaat tussen beiden op het niveau van het be­drijf. Deze correlatie is onbeduidend wanneer men hierbij verschillende bedrijfs­typen betrekt; maar ze wordt terug duidelijk wanneer bedrijven met verwante bedrijfsstruktuur vergeleken worden.

De aandacht wordt gevestigd op het feit dat een keuze dient gemaakt te wor­den tussen een interpretatie van landkenmerken of landkwaliteiten.

Men illustreert de waarde van de studie van het bodemgebruik als bodemge­schiktheidsparameter .

Verder blijkt dat de studie van de behoeften van de verschillende gewassen de basis vormt voor landevaluatie.

Evaluation des critères pédologiques et topographiques en relation avec Ie potentiel d'utilisation des terres en Europe

Résumé

Les systèmes d'évaluation des terres peuvent être subdivisés en deux groupes : les systèmes d'évaluation générale et les systèmes ou l'évaluation est faite pour un usage bien déterminé. Lors de l'application un choix s'impose entre ces deux systèmes.

Une étude comparative entre l'évaluation quantitative et qualitative est donnée pour la culture du froment en Belgique. eeci indique des relations étroites au niveau de la ferme; cependant cette correlation devient insignifiante, si les mé­thodes culturales sont très variables; d~autre part elle se manifeste de nouveau si on considère les fermes qui appartiennent à un type d'exploitation comparable.

On attire l'attention sur Ie fait qu'un choix doit être fait entre une evaluation basée sur des caractéristiques ou une évaluation basée sur des qualités.

L'étude de l'utilisation des terres comme paramètre d'évaluation est illustrée. On attire l'attention sur l'importance de l'étude des exigences culturales comme

base d'évaluation.

190

PEDOLOGIE, XXXI, 2, p. 191-206, Ghent,1981

L'AGROMETEOROLOGIE, DOMAlNES, OB]ECTIFS ET MOYENS

N. GERBIER

Document de synthèse établi par Ie Groupe de Travail Permanent de la Commission Agriculture du Conseil Supérieur de la Météorologie.

1. DEFINITION ET DOMAINES DE L'AGROMETEOROLOGIE

1.1. Définition

L'agrométéorologie peut être considérée comme l'ensemble des moyens scientifiques et techniques permettant, par l'exploitation de données à la fois agronomiques et météorologiques, de procurer à l'exploitant agricole, des éléments utiles pour une meilleure gestion de son exploitation.

Sa mise en oeuvre comporte deux aspects essentiels : - la prise de conscience par les responsables de l' Agriculture à tous les

niveaux de l'impact des facteurs climatiques sur la production.; - l'utilisation rationnelle de la connaissance des facteurs climatiques

lors de la prise de décision.

C'est grace à la recherche et au développement que Ie premier as­pect pourra être traité alors que Ie deuxième débouche sur les applica­tions pratiques en vue d'une part de minimiser les effets nocifs du climat ou au contraire d'en accentuer les incidences bénéfiques et d'au­tre part d'optimiser les interventions culturales et les équipements.

L'action de l'agrométéorologie s'étend des couches du sol suscep­tibles d'influencer Ie développement et la croissance des végétaux les mieux enracinés, aux niveaux moyens de l'atmosphère ou peuvent être entrainés les spores, pollens et insectes.

N. Gerbier - Direction de la Météorologie Nationale, 2 Av. Rapp 75340 Paris Cedex 07, France.

191

1.2. Domaines

Les principaux domaines d'application de l'agrométérologie peuvent être classés en 7 rubriques :

i) Orientation régionale de l'agriculture Les données agroclimatiques constituent un facteur essentiel pour

l'estimation de la potentialité agricole d'une région en fonction des sites et des types de production (zonage pédoclimatique). Ces in forma­tions peuvent contribuer à l'introduction de productions agricoles nouvelles, de méthodes culturales et d'équipements mieux adaptés aux circonstances atmosphériques, en particulier dans Ie domaine drainage - irrigation. Elles peuvent conduire également à exprimer des besoins en recherches dans ces domaines.

iij Choix d'une orientation technico-économique à moyen terme pour la communauté agricole Comparaison entre Ie climat et les exigences écoclimatiques des

productions envisageables. Introduction des critères du climat dans les modèles "gestion agricole".

iii) Techniques de production agricole (végétale ou animale) et sylvi­cole

Adaptation des interventions culturales et des équipements aux ca­ractéristiques physiques de l'environnement, en prenant compte en particulier la fréquence et la durée des épisodes favorables à ces inter­ventions au cours de l'année agricole : - travail du sol, - épandage d'engrais, - interventions culturales, - récoltes, fenaison, etc ...

Mise en application de ces interventions au moment Ie plus oppor­tun en tenant compte des observations du temps passé récent et des prévisions météorologiques à courte échéance.

iv) Protection sanitaire 11 convient de tenir compte des incidences du climat à la fois sur

l'hote et l'agent pathogène. Les équipements de prévention, la fré­quence des interventions phytosanitaires résultent en partie des condi­tions climatiques habituelles, tandis que la décision d'intervenir dé­pend de la situation atmosphérique des jours précédents et de la pré­vision pour les heures et Ie jour à venir: températures, vent, précipita­tions, humidité. De même les informations météorologiques et clima­tiques sont de grande .utilité dans la phase critique "étable-champs" (sensibilité aux maladies ).

192

v) Gestion des resources hydriques en concertation avec les autres usagers de l'eau et recherche d'une meilleure valorisation de l'eau disponible. Le choix et Ie dimensionnement d'un système d'irrigation, l'implan­

tation d'un lac collinaire, la mise en place d'un réseau de drainage se­ront fonction d'une part de la consommation en eau des cultures do ne de l'insolation, des températures, du vent et d'autre part des apports naturels dus aux précipitations.

La conduite de l'irrigation peut être pilotée à l'aide des mesures cu­mulées des paramètres atmosphériques permettant de suivre l'évolu­tion du bilan hydrique et par conséquent des réserves utiles en eau du sol.

vi) Aménagement de l'espace rural Certains aménagements ruraux tels que la déforestation, l'arasement

des haies sont susceptibles de modifier Ie climat à l'échelle locale, par exemple la fréquence des gelées ou Ie niveau de l'évapotranspiration. 11 pourra être utile d'évaluer l'amplitude de ces changements et leurs répercussions sur la production.

vii) Prévention des calamités atmosphériques Toute implantation de culture sensible au gel, à la grêle, à la séche­

resse devrait être précédée d'une étude permettant de connaître la fré­quence de ces calamités et de délimiter les zones les moins atteintes en fonction des types de cultures et de la sensibilité de leurs stades phénologiques. Tenir compte de la délimitation des zones gélives est bien souvent la première précaution à prendre pour limiter les risques des dégats dus au gel.

Ces mêmes études doivent contribuer aux choix des équipements de prévention les plus rentables. Pour Ie gel, Ie choix entre chaufferet­tes, aspersion, brassage de Pair dépend de la nature des gelées, de leur fréquence, de la topographie du site etc ... Leur mise en oeuvre peut être déclenchée à partir d'avis de gel diffusés par les services agromé­téorologiques. Les modifications artificielles du temps, reposant sur des données météorologiques et climatiques, doivent être prises en considération : pluie artificielle, grêle ...

1.3. Actions

Pour exploiter au mieux les possibilités de l'agrométéorologie dans chacun des domaines cités, il convient de définir et de réaliser des actions dans quatre domaines :

i) Analyse technique des besoins exprimés par les agriculteurs et les

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responsables régionaux et nationaux de la Profession et de l'Adminis­tration. Détermination de projets de recherche.

ii) Programmes de recherches agronomiques et météorologiques con­certés en vue de répondre aux besoins exprimés, non satisfaits à l'aide des techniques disponibles.

iii) Formation des protagonistes de l'agrométéorologie. C'est un aspect essentiel car il s'agit de former à coté d'agrométéorologistes compétents, les enseignants et les conseiller agricoles, ainsi q~e les agri­culteurs eux-mêmes. L'utilisation rationnelle des informations agro­météorologiques implique en effet une participation active de l'usager (relevé de données, interprétation d'avis ou de conseil) qui exige cer­taines connaissances de base. Sans une sensibilisation et une formation à tous les niveaux, les efforts réalisés par quelques spécialistes seraient valns.

iv) Estimation de I 'impact économique des programmes agronlétéo­rologiques envisagés; détermination des priorités.

Dans un souci d'efficacité on devrait s'attacher en priorité à la for­mation de conseillers agricoles et des enseignants. 11 serait souhaitable que dans chaque département un conseiller reçoive une solide spécia­lisation agrométéorologique dont il ferait bénéficier ses collègues.

2. MODALITES D'UTILISATION ET IMPACT DES INFORMA~ TIONS AGROMETEOROLOGIQUES

2.1. Modalités d'utilisation

Les informations agrométéorologiques sont à prendre en compte à chaque étape de la gestion des activités agricoles.

2.1.1. Les engagements "stratégiques" à long terme devraient être adaptés en tenant compte des critères climatiques exprimés en termes statistiques objectifs (fréquence d'occurence d'évènements atmosphé­riques ou de franchissement de seuils), associés aux données physiques (pédologiques notamment) et économiques. 11 s'agit en particulier de l'aménagement de l'espace rural (brise-vent, drainage, suppression du bocage, etc ... ) du choix des productions et des techniques culturales (irrigation, assolement ... ), de la nature des équipements (système de fanage, ... batiments agricoles, serres, ... ).

2.1.2. A moyen terme, c'est-à-dire au cours d'une campagne agri­cole, on ne dispose pas de méthodes de prévisions météorologiques ef­ficaces susceptibles de répondre aux besoins de l'agriculture, par contre il existe des modèles de prévisions dites "agrométéorologiques"

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fournissant, à l'échelon régional ou national, une estimation anticipée satisfaisante à quelques semaines ou quelques mois d'échéance du volume (grace aux prévisions de rendement et à condition de connaitre les surfaces concernées) et de la qualité de certaines récoltes (blé, betteraves sucrières, maïs, pommes de terre, vigne ... ). De telles prévi­sions, très utiles pour l'organisation et la rationalisation des marchés, sont basées essentiellement sur l'utilisation dans des modèles mathé­matiques des facteurs atmosphériques relevés aux stades précoces de développement des cultures (insolation, températures, précipitations, vent, etc ... ).

Suivant les mêmes techniques d'analyse, des modèles de prévisions régionales des dates de franchissement de seuils phénologiques (date de la floraison, de la maturation, etc ... ) sont opérationnels et peuvent guider les agriculteurs dans la détermination d'un calendrier d'inter­ventions (façons culturales, engrais, interventions phytosanitaires, ré­colte ... ) particulièrement utiles dans Ie contexte actuel d'économie d'énergie.

2.1.3. A court terme les choix tactiques de l'agriculteur peuvent être facilités par diverses catégories d'informations météorologiques.

i) Prise en compte de relevés climatiques récents (par exemple cu­muls de précipitations, de températures) en vue d'estimer objective­ment l'évolution biologique du milieu vivant (végétaux, agents patho­gènes), Ie bilan hydrique des cultures ou encore l'état du sol (réserve en eau), température . C'est ainsi que peuvent être mieux ajustés des dates de semis ou le déclenchement d'une campagne d'irrigation.

ii) Prévisions météorologiques et avis à court terme susceptibles d'orienter les interventions de l'agriculteur : traitements phytosani­taires, irrigation, lutte contre Ie gel, fenaison, etc ...

iü) L'emploi de statistiques climatologiques, à partir des circonstances climatiques actuelles, peut permettre d'évaluer le risque de subir telle ou telle situation dangereuse ou nocive : par exemple probabilité pour qu'un état de sécheresse se poursuive ou risque de gelées au printemps après que les températures cumulées, depuis Ie début de l'année, aient dépassé un certain seuil.

2.2. Impact des informations agrométéorologiques

Celui-ci se manifeste à la fois au niveau de l'exploitation agricole et sur Ie plan régional et national. Il est également important dans les plans de développement tant au niveau de l'exploitant que du dépar­tement.

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2.2.1. Au niveau de l'exploitation, l'utilisation rationnelle des infor­mations agrométéorologiques se traduit par:

i) un choix plus judicieux des productions agricoles, des techniques culturales et des équipements ;

ii) une conduite de l'exploitation adaptée aux caractéristiques du climat local par exemple avec la connaissance de jours disponibles ou séquences de jours disponibles pour certains travaux, et une estimation objective des risques climatiques conduisant à un comportement plus rationnel de l'agriculteur vis à vis des aléas climatiques ;

iii) une agriculture plus économe, grace à la limitation des pertes (en production, produits phytosanitaires, engrais, énergie, etc ... ) résul­tant des circonstances atmosphériques défavorables ou, au contraire, d'une meilleure utilisation des périodes favorables ;

iv) une amélioration de la productivité de l'exploitation ainsi que de la qualité des produits ;

v) un allègement des contraintes de travail de l'agriculteur en évi­tant les intervetions inutiles.

2.2.2. Au plan régional et national, ces informations doivent contri­buer à :

i) une estimation objective du potentiel agricole de chaque zone pédoclimatique homogène;

ii) une orientation plus rationnelle des productions agricoles, des aménagements (irrigation, drainage, brise-vent ... ), des équipements dans chacune de ces zones ;

iii) la 'régularisation des rendements débouchant sur un approvision­nement plus régulier des marchés et réduisant ainsi les fluctuations ex­cessives des cours, préjudiciables tant aux producteurs qu'aux con­SOITlmateurs ;

iv) l'approvisionnement plus uniforme des industries agro-alimen­taires en aval.

3. INCIDENCES DES FACTEURS ATMOSPHERIQUES SUR LES PRODUCTIONS AGRICOLES

3.1. La production agricole résulte de la combinaison et des interactions de quatre facteurs principaux :

- Ie sol, y compris sa faune et sa flore, - les conditions climatiques, - Ie matériel biologique, en incluant les agents pathogènes, végétaux

ou animaux, - les techniques agricoles (y compris élevage, sylvïculture, ... etc.).

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3.2. Incidences des principaux facteurs climatiques

i) Le rayonnement solaire est en jeu dans: - la photosynthèse, - Ie photopériodisme (effets cycliques), - les phototropismes, - l'induction des stades de déve1oppement.

Tandis que l'action de la température se manifeste par: - l'existence de seuils biologiques ou de sensibilité (tant sur les végé-

taux que sur les animaux), - les effets cumulatifs (degrés-jours), - les thermopériodismes (effets cycliq ues), - les incidences sur les échanges hydriques.

ii) L'eau intervient : - en tant que constituant des cellules vivantes, - comme élément indispensable au déroulement du métabolisme des

tissus, - dans l'approvisionnement des végétaux en sub stances minérales ex­

traites du sol, - dans les échanges avec Ie milieu ambiant (évapotranspiration, régu-

lation stomatique ... ), - sur l'attitude des organes herbacés (turgescence), - sur l'état phytosanitaire des cultures (humectation), - sur la structure biochimique et pédologique des sols, - sur la structure physique des sols: battance, érosion.

iii) L'agitation de l'air concerne : - Ie transport aéroporté d'éléments organiques vivants (spores, insec­

tes, pollens, ... ), - les effets mécaniques des vents forts sur les organes aériens fragiles, - son action sur Ie niveau d'évapotranspiration (à la limite sur l'échau-

dage), - l'érosion éolienne des terres arables, - Ie rale et la mise en place des brise-vents, - l'aménagement rural.

iv) Les variations de la pression atmosphérique et de l'électricité statique affectent les animaux d'élevage.

v) L'adaptation des races est également liée aux conditions climati­ques régionales.

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4. BESOINS DE L'AGROMETEOROLOGIE EN MATIERE DE DON­NEES D'OBSERVATIONS ET DE RESEAUX

4.1. Données de base à collecter

L'agrométéorologie traitant des interactions entre Ie milieu naturel (atmosphère et sol), les types de productions et les interventions cultu­rales, deux catégories de données devront être collectées.

4.1.1. Données climatiques - valeurs quotidiennes, pluriquotidiennes ou extrêmes des paramètres

physiques de l'atmosphère (températures, précipitations, teneur en vapeur d'eau de l'air, insolation, rayonnement, évapotranspiration, agitation de l'air, dépots aqueux) ;

- occurence d'évènements atmosphériques : brouillard, neige, grêle, orage, gelées et dégats observés ;

- durée de certains évènements : humectation des organes végétaux aériens, gelées, précipitations, taux d'humidité de Pair.

4.1.2. Données agronomiques

i) Données pédologiques : - caractéristiques hydriques et hydrodynamiques des sols: capacité

de rétention, point de flétrissement permanent, réserve utile et ré­serve facilement utilisable ;

- caractéristiques thermiques : conductibilité thermique pour divers taux d'humidité, chaleur massique;

- état du sol en surface : tassé, travaillé, mulch, couverture temporaire ou permanente ... etc.

ii) Données biologiques : - état des cultures du point de vue :

- développement, - sanitaire,

- date de franchissement des stades phénologiques identifiés de façon objective et uniforme,

- mesures biométriques, - rendements.

iii) Données relatives aux techniques culturales : - modalités et dates de préparation des sols, - modalités des interveritions phytosanitaires et épandages d'engrais, - mise en oeuvre des moyens de prévention contres les aléas climati-

ques : gel, irrigation ... etc" - modalités et dates d'interventions culturales.

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4.2. Modalités de collecte de ces données.

4.2.1. Données climatiques

a) Pour être comparables, cohérentes et utiles les données climatiques doivent être collectées et rassemblées suivant des règles précises et uniform es en utilisant des équipements dont les résultats sont compa­tibles. L'ensemble des postes d'observations dont les mesures sont rassemblées par un même organisme est intitulé réseau d'observations. 11 existe en France des réseaux à vocation nationale : réseau de la Mé­téorologie Nationale, Ie plus dense, du Service de la protection des Végétaux, de l'I.N.R.A., du Service de l'Hydraulique du Ministère de l'Agriculture; des réseaux départementaux ou pluridépartementaux, réseaux des commissions météorologiques départementales, de la pro­fession agricole, des associations climatologiques, des sociétés d'amé­nagement rural ... etc.

b) La densité des mesures n'est pas toujours suffisante et il parait souhaitable d'implanter dans chaque département quelques postes agroclimatologiques (2 à 5) ou seraient mesurés et enregistrés les tem­pératures sous abri ainsi qu'à plusieurs niveaux au-dessus et en-dessous de la surface du sol, l'humidité de l'air (durées de franchissement de seuil) , Ie rayonnement solaire, la teneur en eau du sol, les évapotrans­pirations, Ie vent, Ie nombre et la densité des grêlons, l'épáisseur de la neige.

Des observations phénologiques concernant les plantes naturelles ou cultivées devraient compléter les mesures physiques.

c) Les instruments utilisés pour mesurer les grandeurs climatiques ainsi que leur implantation et leurs modalités d'utilisation doivent être normalisés et conformes aux spécifications de la Météorologie Nationale. En particulier les unités de mesure, la fréquence et les ho­raires des relevés, les modalités de concentration des données doivent se conformer strictement aux règles en vigueur afin d'éviter par la suite les erreurs d'interprétation.

d) Pour être efficace, la surveillance de l'atmosphère doit être per­manente, condition difficile à réaliser en dehors des stations météoro­logiques tenues par des professionnels. D'autre part l'utilisation opé­rationnelle en-:temps quasi-réel de certaines données (surveillance des bilans hydriques, des bilans thermiques ... etc), exige leur concentra­tion rapide. C'est pourquoi la mise en place de réseaux automatisés de mesures climatiques parait, à terme, une solution indispensable. Elle a l'avantage de permettre l'éclatement rapide des données à de multi­pIes organismes interprétateurs chargés de renseigner les usagers agri­coles. Afin d'éviter les duplications onéreuses, l'installation de tels ré-

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seaux doit être parfaitement coordonnée. Le Conseil Supérieur de la Météorologie dans lequel tous les utilisa­

teurs potentiels de la Météorologie sont représentés est à même d'assu­rer cette coordination.

e) Depuis quelques années se développent de nouvelles techniques de collecte de données auxquelles l'agrométéorologie se doit de faire appel. Les radars météorologiques permettent d'identifier et de locali­ser les précipitations (pluie, grêle, orages), et des recherches sont entre­prises en vue de déboucher sur des mesures de quantité de pluies.

D'autre part la télédétection à partir de diverses plateformes (aéro­nefs,satellites) se développe. En particulier la localisation des zones gélives à partir de mesures radiométriques en infra-rouge faites par avion parait prometteuse. Les informations transmises par les satellites météorologiques permettent d'affiner les prévisions météorologiques à courte échéance.

4.2.2. Données agronomiques

a) Données pédologiques Afin de normaliser les travaux pédologiques ainsi que les réalisations

cartographiques qui en découlent, l'I.N.R.A. a été chargé de créer en 1968 Ie. Service des Sols et de la Carte Pédologique de France au 1/100.000.

Un certain nombre de documents de travail sont élaborés qui sont des fiches d'observations de terrain (ces fiches sont généralement com­plétées par des descriptifs de l'environnement géomorphologique, géo­logique et hydrologique ainsi que des considérations sur les environne­ments climatique, végétal et humain) :

i) la fiche "description d'un profil cultural" renseigne sur la struc­ture, l'aspect des différents horizons et Ie développement des racines pour rendre compte du résultat d'une technique culturale ou de l'as­pect du sol supportant une culture ;

ii) la fiche "description de l'état du sol" analyse la consistance des différents horizons, pour déterminer par exemple les jours disponibles pour la réalisation des travaux, les irrigations ;

üi) la fiche "description de l'état d'un Zit de semence" permet de décrire un semis et ainsi d'expliquer la levée (elle ne dispense cepen­dant pas de comptages de levée classique qui appartiennent au volet biologique étudié ci-après).

b) Données biologiques et données relatives aux techniques culturales En égard à la complexité du problème que pose la saisie des données

biologiques dans Ie monde animal, on se bornera à l'étude des produc-

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tions végétales; c'est pourquoi la parcelle expérimentale (on enquêtée) est l'unité fondamentale à observer.

L'ensemble des fiches qui peuvent être établies pour rendre compte de l'état et de l'évolution d'une production végétale cultivée peut se résumer de la façon suivante :

i) une fiche initiale caractérisant la parcelle et son équipement ainsi que la plantation,

ii) une fiche d'opérations culturales et d'observations sanitaires, iii) une fiche annuelle sur la croissance et les stades phénologiques

avec prise en compte des accidents entraînant une perte de récolte (asphyxie, gelée, grêle, sécheresse, vent, parasitisme ... ),

iv) une fiche annuelle production permettant de caractériser la ré­colte y compris la qualité du produit à la récolte et après stockage ou transformation.

La création de ce fichier de données agronomiques doit tendre vers deux objectifs : - constituer un receuil de données qui, grace à sa normalisation, puisse

permettre des études comparatives (d'un lieu à un autre, d'une va­riété à l'autre, d'une année à l'autre ... ) tout en satisfaisant les diffé­rents besoins de la profession agricole,

- cumuier les informations provenant de différentes sources (profes­sion, instituts techniques, recherche ... ) afin d'accroître les perfor­mances et la diversité des études nécessaires au développement de nos connaissances agronomiques.

5. NATURE DES RENSEIGNEMENTS DESTINES A L'AGRICUL­TURE

5.1. L'efficacité pratique des informations agrométéorologiques im­plique la réalisation simultanée de 5 conditions

i) connaissance de la sensibilité des productions agricoles aux fac­teurs climatiq ues,

ii) capacité technique pour Ie service agrométéorologique de fournir les informations requises (fréquence d'occurrences d'évènements cli­matiques ou prévisions ayant un degré de confiance satisfaisant),

iii) existence de moyens de diffusion rapide de ces informations, ce qui n'est pas toujours évident pour des usagers aussi dispersés que les agriculteurs,

iv) formation de base permettant à l'usager d'interpréter judicieuse­ment les renseignements reçus,

v) éventualité pour l'usager agricole d'un choix rationnel basé sur ces renseignements (un ai-boriculteur qui ne dispose pàs de dispositif de

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prévention contre Ie gel n'a que faire d'avis de gelées).

5.2. Renseignements agrométéorologiques utiles à l'agriculteur

Ceux-ci se présentent sous trois aspects : - renseignements climatologiques, - données agrométéorologiques relatives au temps passé récent et à

l'état actuel, - prévisions agrométéorologiques adaptées aux besoins de l'agriculture.

5.2.1. Les renseignements climatologiques, sont extraits des fichiers constitués à partir des données recueillies dans les divers réseaux et ayant fait l'objet de contróles de qualité. I1 se présentent sous plusieurs formes: - des séries chronologiques de sélections de mesures ou d'observations:

par exemple la série des températures minimales au printemps, - les caractéristiques statistiques simples des principales grandeurs at­

mosphériques : moyennes, médianes, quintiles. Par exemple, les minimums de température à Dijon en Janvier sont en moyenne de -1,60 ; dans 50 % des cas elles sont inférieures à _1 0 (médiane), mais dans 20 % des cas elles sont supérieures à +0,6 0 (4ème quintile),

- les fréquences de franchissement de seuils pour les températures minimales ou maximales, l'humidité de l'air, la teneur en eau du sol, Ie vent ... etc.,

- les fréquences d'occurrences des valeurs cumulées de facteurs agro­mété<?rologiques au cours de certaines périodes (décade, lnois, sai­son) : hauteurs des précipitations, degrés-jours, évapotranspiration, bilans hydriques ... etc.,

- les fréquences des jours ou des séquences de quelques jours consé­cutifs présentant certains caractères communs : nombre de jours de ressuyage des sols, séquences de jours consécutifs sans pluie au mo­ment de la fenaison, fréquence des jours favorables aux diverses interventions culturales, ... etc.,

- les durées cumulées d'états particuliers : durée des gelées au prin­temps, durée des humidités de l'air supérieures à 80 % et 90 %, du­rée de l'humectation des végétaux, durée des précipitations ... etc.

Cette documentation peut se présenter soit sous forme de tableaux numériques, soit sous forme d'atlas agrométéorologiques.

5.2.2. Données relatives au temps passé récent

La prise en compte des données climatiques des jours ou des se­maines antérieures, complétées par des observations biologiques ou

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pédologiques permet une surveillance de certains états actuels des pro­ductions, par exemple : - réserves hydriques du sol et par conséquent éventuelles déficiences

de la végétation, - état thermique et hydrique du sol pour estimer par exemple la date

la plus favorable des semis, - état physiologique de culture ou d'agents pathogènes ~n prenant

en compte la succession du bilan hydrique ou des sommes de tem­pératures.

Certaines des données utilisées, en particulier celles qui présentent la plus grande variabilité spatiale comme les tem pératures minimales ou les précipitations ont intérêt à être prélevées sur l'exploitation agri­cole elle-même. Dans ce cas il conviendra d'implanter pluviómètres et thermomètres en se conformant aux normes en vigueur dont on peut prendre connaissance dans les stations de la Météorologie Nationale.

5.2.3. Prévisions météorologiques et agrométéorologiques

Deux catégories fort différentes de prévisions sont susceptibles d'in­téresser l'agriculture : les prévisions du temps (prévisions météorolo­giques) et les prévisions de récoltes (prévisions agrométéorologiques).

i) Prévisions du temps (prévisions météorologiques) 11 s' agit de prévisions à courte échéance (q uelq ues heures à 5 jours)

puisqu'actuellement il n'existe pas de méthodes permettant d'élaborer dès prévisions du temps à plus long terrne, ayant un degré de confiance acceptable. Elles se présentent tantot sous forme d'une description de l'évolution ultérieure des paramètres climatiques intéressant l'agricul­teur (pluies, températures, vent), tantot sous forme d'avis de phéno­mènes dangereux : gel, grêle, tempête, orage.

Ces prévisions doivent être adaptées aux besoins particuliers des productions ' agricoles d'une région et par conséquent tenir compte du calendrier des travaux agricoles et des stades phénologiques atteints (plantes, animaux d'élevage, agent pathogènes) afin de décrire avec Ie maximum de précision l'évolution des éléments climatiques les plus actifs. La rédaction de ces prévisions demande une étroite coopération entre Ie service météorologique local (station départementale) et la profession agricole (en généralle SUAD ou une association climato­logique) afin d'inclure dans un texte concis et précis exclusivement ce qui intéresse les agriculteurs.

D'autre part, en raison de la variabilité spatiale de la répartition des critères climatiques, chaque usager doit être en mesure d'interpréter ces prévisions pour les adapter aux circonstances particulières de son

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exploitation, en tenant compte des données climatiques collectées sur place (températures extrêmes, vent, pluviométrie), ce qui implique que les utilisateurs de ces prévisions aient reçu une formation agromé­téorologique appropriée.

Ön notera qu;un Centre Européen de Prévision Météorologique à moyen terme fonctionne à Reading en Grande-Bretagne et que son ob­jectif est de réaliser des prévisions du tem ps à 10 jours d'échéance avant 1985.

ü) Frévisions de récoltes (prévisions agrométéorologiques) I1 s'agit, comme il a été indiqué dans Ie paragraphe 2.1.2., d'estima­

tions à échéance de plusieurs semaines soit du rendement et de la qua­lité des récoltes futures, soit de l'évolution phénologique des cultures: dates de floraison, de maturation, etc ...

Ces prévisions agrométéorologiques sont susceptibles d'intéresser à la fois les responsables de l'organisation des marchés et les producteurs.

5.3. ModaHtés de diffusion des informations agrométéorologiques

La dispersion des agriculteurs (il existe un peu plus d'un million d'exploitations en France) rend Ie problème de la diffusion, en temps opportun, des informations agrométéorologiques particulièrement dé­licat à résoudre, lorsqu'il s'agit de données à utiliser dans l'immédiat par exemple : prévisions du temps, avis de phénomènes dangereux, évapotranspiration, somme de températures, avis d'irrigation, etc ...

Les n;nseignements à utiliser en temps différé tels que les informa­tions agroclimatologiques (tableaux numériques, atlas, valeurs men­suelles, séries chronologiques ... ) peuvent faire l'objet de diffusion sous une forme adaptée à l'utilisateur (ouvrages ou bulletins envoyés par voie postale ou publiés dans la presse spécialisée).

Par contre, les renseignements opérationnels à utiliser en temps quasi réel deviennent vite périmés, il convient donc de les mettre ti-ès rapidement à la disposition des usagers. Seules les télécommunications peuvent répondre à ce souci de rapidité; on peut envisager : - les répondeurs téléphoniques spécialisés en agrométéorologie. Les

messages devant être très courts, chaque répondeur devrait corres­pondre à une zone agroclimatique relativement homogène au point de vue production. Leur approvisionnement devrait résulter d'une étroite collaboration entre les services météorologiques, qui sont souvent les seuls à pouvoir assurer une surveillance permanente, la profession agricole (SUAD ou association climatologique) et les ser­vices de l' Agriculture (DDA, CTGREF, Protection des végétaux, INRA);

204

- les média audiovisuels : (t élévision et radiodiffusion régionales). Des accords entre la profession agricole, les services techniques con­cernés et les chaines publiques ou privées peuvent permettre la dif­fusion, à des heures utiles, d'informations agrométéorologiques ;

- Dans un avenir pas trop éloigné (quelques années à une dizaine d'an­nées), Ie développement de la téléinformatique devrait permettre aux abonnés, à l'aide de systèmes de diffusion appropriés, de puiser dans des fichiers spécialisés leur fournissant des informations très diversifiées do nt des informations agrométéorologiques.

Résumé

L'impact des facteurs climatiques sur la production agricole est évident et de ce fait, l'agrométéorologie est un élément important dans les études d'évaluation des terres.

Les connaissances agrométéorologiques influencent non seulement l'orientation régionale de l'agriculture, notamment en comparant Ie climat et les exigences éco­climatiques des productions envisageables, mais aident aussi à la protection sani­taire et à la gestion des ressources hydriques. Son impact se manifeste à la fois au niveau de l'exploitation agricole que sur Ie plan régional et national.

Les facteurs climatiques ont une incidence sur tout les niveaux de la produc­tion agricole depuis la photosynthèse et Ie thermopériodisme jusqu'à l'état phyto­sanitaire des _plantes, Ie rale et la mise · en place des brise-vents. Dans cette opti­que une meilleure collecte des données et la mise en place d 'un réseau plus dense pourrait être des plus bénéfiques pour l'agriculture et pour les sciences qui se proposent d'étudier la vocation des terres.

Agrometeorology, field, objectives and possibilities

Summary

The influence of the climate on agriculture is obvious. Hence, agrometeorologic­al data are of a paramount importance in land evaluation research.

Agrometeorological observations have not only an impact on the regional orientation of the agricultural production, particularly in comparing the climate with the ecoclimatical erop requirements but they iilterfere also in the fields of phytosanitary protection and exploitation of water resources. Benefits can be achieved at the level of individual farms as on an overall regional or national basis.

Climatic factors have an influence at almost all stages of crop production, in­duding as weIl photosynthesis, thermoperiodism and phytosanitary treatments as the conception of windbreaks. In this respect a better collection of the data and the establishment of a dense network of observation stations can be benefi­cial for agriculture as weIl as for the scientific research on land evaluation.

205

Agrometeorologie, domein, objektieven en mogelijkheden

Samenvatting

De rol van het klimaat op de landbouwproduktie is duidelijk en in dit verband kan gesteld worden dat agrometeorologische gegevens uiterst belangrijk zijn voor landevaluatie studies.

De agrometeorologie oefent niet alleen een invloed uit op de regionale oriën­tatie van de landbouw, o.a. door het klimaat te vergelijken met de ecoklimatolo­gische groeivoorwaarden voor de gewassen, maar ze interfereert ook in het fyto­sanitair domein en in de waterexploitatie. De voordelen ervan zijn voelbaar op alle niveau's van de exploitatie.

De klimaatsfaktoren komen nagenoeg tussen op alle niveau's van de landbouw­produktie, gaande van de fotosynthese en het thermoperiodisme tot de fytosani­taire behandelingen en het opstellen van windschermen. In dit verband kan een betere gegevensverzameling en het opstellen van een dicht netwerk van observatie­stations zeer ten goede komen aan de landbouw en aan het bodemgeschiktheids­onderzoek.

206

PEDOLOGIE, XXI, 2, p. 207-242, 16 tab., 1 fig. Ghent, 1981

STATE OF KNOWLEDGE AND PROBLEMS RELAT­ED TO THE DEFINITION AND DELIMINATION OF FARMING SYSTEMS AND LAND UTILIZATION TYPES IN EUROPE

].LEE

1.INTRODUCTION

1.1. FARM TYPOLOGY AND LAND UTILIZATION TYPE

Beek (1975) defines land utilization type as "a specific subdivision of a major kind of land-use, serving as the subject of land evaluation and defined as precise1y as is practical in produce terms, level of management, farm size etc. It is a technical organizational unit in a specific socio-economic and institutional setting". The selection and formulation of land utilization types is se en as an integral part of the land evaluation procedure according to Beek (1975). Kostrowicki (1976) through the International Geographical Union (IGU) has made considerable progress in arriving at a modern typology of world agri­culture in terms of land utilization types. The basis of his approach is to distinguish the typifying (diagnostic) characteristics of holdings on the basis of sample studies of individual holdings. Type of agriculture is understood by Kostrowicki as follows : - "as a more or less established form of erop growing and/ or live­

stock breeding for production purposes that can be described by the characteristic set or association of its attributes;

- as a supreme and overall concept in agricultural classification, com­prising all other concepts such as land tenure systems, land-use systems, cropping systems, type of farming, etc.;

- as a hierarchical concept encompassing types of various orders, fr om basic ones identified by the study of individual holdings, through types of several intermediate orders identified on the basis of a study of various aggregate units - to the highest order - world types of agriculture;

Lee J. - An Foras Taluntais, Johnstown Castle, Wexford, lreland.

207

- as a dynamic concept changing in an evolutionary or revolutionary way alongside with a change of its basic attributes".

The typology is not to be confused with regionalization as the type concept is of a taxonomic character, while the character of a region is spatial or territorial. The basic components in the eluddation of the typology are the agricultural attributes of the holding. The type of agriculture is defined by KostrowiCki as :

o T= S ~ C P

in which T = Type of agriculture S = Sodal attribu tes 0= Operational attributes P = Production attributes C = Structural attributes.

Sodal attributes relate to the forms of land ownership, tenure and size of holdings. Operational attributes represent labour and capital inputs e.g. labour intensity, mechanization, fertilization, irrigation, intensity of land-use, livestock density, system of farming. Production attributes relate to land productivity (agricultural output), labour productivity, degree of commercialization. Structural attributes relate to production orientation e.g. (1) proportion of permanent grassland to total ag ri­culturalland; (2) proportion of land under food crops to total agri­culturalland; (3) proportion of animal products to gross agricultural production ; (4) proportion of industrial crops in gross agricultural pro­duction.

Kostrowicki emphasizes that this typology is limited to a considera­tion of internal (endogenous ) attributes while external (exogenous) attributes are excluded, e.g. the influence of land conditions on the formation of agricultural types. In this connection Beek (1975) ex­plains that Kostrowicki's definitions of the agricultural types are not functional in the sense that the relationships between land and land utilization can be easily deduced. The key attributes are not evaluated for explicit recognition of the abilities of the agricultural type to manage, conserve or improve the land nor for an easy recognition of its land requirements. To suit its purpose land evaluation needs more functional descriptions. Land evaluation is concerned with the predic­tion of land use performance on the basis of a critical comparison of land requirements and use abilities as related to the land conditions.

Present land-use, as elucidated by Kostrowicki and the International Geographical Union (1976) is important both as a yardstick for the conlparison of planned uses and as a relevant use to be considered in

208

Table 1

Struetured list of types of agrieulture in Europe, adapted from Kostrowieki (1976)

Symbol Orientation of produetion Farm size Produee Region of oeeurrenee Kostrowieki

1. Traditional Small scale Mixed agriculture Tem Extensive eurrent-follow subsistenee Mixed Some parts of Europe

to semi-subsistenee Tmo Semi-commercial Mixed with crops prevalent Mediterranean eountries Tmm Semi-commercial Mixed Some less developed

Mixed: livestock breeding prevalent parts of Europe

Tml Semi-commercial Parts of Europe

2. Traditional Large scale Agriculture Lcc Traditional latifundia Crop growing prevalent S. Europe LU Traditional latifundia Livestock breeding prevalent S. Europe

3. Market oriented Small scale Agriculture Mng Commercial Vegetable growing Europe (Suburban zones) Mnt Commercial Fruit growing S. Europe Mme Commercial Mixed : erop growing prevalent S. Europe Mmm Commercial Mixed C. Europe, W. Europe Mmn Commercial Mixed : industrial crop growing C. Europe, W. Europe

prevalent Mml Commercial Mixed : live stock prevalent N.W. Europe

4. Market oriented Large scale Agriculture Mxm Commercial Mixed agriculture W. Europe Mvm Intensive irrigated Mixed crop growing S. Europe Mvh Commercial Horticulture W. Europe

tv 5. Highly industrial~zed Agriculture 0 Muu Highly industrialized Livestock breeding Europe \0

Mgg Highly industrialized Crop growing Europe

evaluation. Hence, it can help in the definition of land utilization types. Table 1 is a structured list of types of agriculture occurring in

Europe as reported by Kostrowicki (1976). These types are likely to comprise the legend for Europe on the I.G.U. World Map.

Beek (1978) asserts that land utilization typing for land evaluation has the "explicit function of enhancing the possibilities for detection of functional relationships between the land utilization type and the land conditions at present and in the future. F or the description and classification of land utilization types, characteristics should be select­ed which are most expedient in making the land utilization type an operational tooI in the land evaluation procedure".

The key attributes of Land Utilization Types as laid down in A Framework for Land Evaluation (1977) include data or assumptions on: (i) produce, including goods (e.g. crops, livestock, timber) services (e.g.

recreational facilities) or other benefits (e.g. wildlife conservation ) , (ii) market orientation, including whether towards subsistence or

commercial production ; (iii) capital intensity which determines the range of possibilities for

applying technology for management, improvement and conserva­tion of the land resources;

(iv) labour intensity; (v) technical knowledge and attitudes of land users; (vii) technology employed (e.g.livestock breeds, machinery), and (viii) infrastructure requirements.

2. SOME ASPECTS OF LAND-USE, FARM STRUCTURE AND FARMING SYSTEMS IN EUROPE

In 1978, the E.E.C. published a comprehensive report entitled "Situation et évolution structurelle et socio-économique des r'égions agricoles de la Communauté". This report includes important informa­tion relevant to delimiting land-u se patterns for each of the 376 administrative units in the Community. In addition, the role of agri­culture in income generation is quantified for each unit. Table 2 shows the distribution of these units by country.

Data tables were included for each of the 376 administrative units which have an average size of 400,000 ha. The scope of the in forma­tion provided is evident from tables 3, 4, 5 which are reproduced from the study. The data on (i) holding size distribution (ii) average holding size (iii) "added agricultural value/ha" and (iv) system of production are highly valuable. The term "system of production" (tabie 3) is more

210

Table 2

Distribution of administrative units by country

Country

F ederal Republic of Germany France Italy Belgium Luxembourg Netherlands Denmark Ireland U.K.

Name of Unit

Regierungsbezirk Departement Provincia Province

ProVincie Amt County County

Number

34 89 94

9 1

11 14 27 97

relevant to a farming typology and in the context of the report , it is arguable that the term land use category is more relevant. In any event each table shows the area of each of the following agricultural land-use categories : (i) arahle land (STL), (ii) permanent pasture and meadow (STH), (iii) permanent crops (SVF), (iv) utilized agricultural area (SAU), (v) cereal area (SCE), (vi) numher of livestock (UGB).

Tables 6-10 which are abstracted from the 'same EEC (1978) study characterise in summary fornl the systems of production and holding sizes for the administrative units of the Federal Republic of Germany, Netherlands, Belgium, Denmark, and Ireland. It might he a profitable exercise to explore the relationship between soil pattern and land-use category. This could he achieved hy systematising the land-use data against the soil units shown on the E.E.C. SoU Map (1: 1 ,000,000). This would seem to be a fundamental component of any project on land resource evaluation.

3. FARM ACCOUNTANCY DATA NElWORK FOR EUROPE

The main purpose of the network is to provide the necessary account­ancy data for an annual determination of incomes and business analysis of agricultural holdings. The results provided by the network are primarily used by the Commission to prepare an annual report on the situation of agriculture and of agricultural markets in the Com­munity.

211

tv I---" tv

Table 3

Agricultural structure, land-use and socio-economie categorisation (Wexford, lrela.nd)

Farm structure 0-2 ha 2-10 ha 10-20 ha

Number of farms 959 1816 1780 11.35 % 21.50 % 21.07 %

Mean farm size 24.39 ha Gini coefficient .48 Utilized agrieultural area per active farmer 131.07 EUR

Production system STL STH SVF 100 ha 100 ha 100 ha 913 1142 5 44.32 % 55.44 % .24 %

~ on agricultural Agricultural Total

Added value (lOS EUR) 498 270 768 64.84 % 35.16 % 100.0 %

Active population (100) 178 105 283 62.90 % ! 37.10 % 100.0 %

Added value/actif person (EUR) 2800 ! 2600 2700

Part of agriculture /Actif / Added value 37.10 35.16

-- ----- ------- -----_ . - --

Source : EEC (1978).

20-50 ha +50 ha Total

2679 1213 8447 31.72 % 14.36 % 100.0 %

SAU SCE UGB 100 ha 100 ha 100 2060 418 2314 100.0 % 20.29 %

Total population 864

Table 4

Agricultural structure, land-use and socio-economie categorisation (Lincolnshire U.K.)

Farm structure 0-2 ha 2-10 ha 10-20 ha 20-50 ha +50 ha Total

Number of farms 160 317 207 342 807 1833 8.73 % 17.29 % 11.29 % 18.66 % 44.03 % 100.0 %

Mean farm size 87.18 ha Gini coefficient .52 Utilized agricultural area per active farmer 24.21 ha Agricultural added value/ha 161.45 EUR

Production system STL STH SVF SAU SCE UGB 100 ha 100 ha 100 ha 100 ha 100 ha 100 1372 225 1 1598 913 837 85.86 % 14.08 % .06 % 100.0 % 57.13 %

Non agricultural ! Agricultural ! Total

Added value (105 EUR) 4305 ! 258 ! .4563 94.35 % ! 5.65 % ! 100.0 %

Active population (100) 933 ! 66 ! 999 Total population 2322 93.39 % ! 6.61 % ! 100.0 %

Added value/ actif person 4600 ! 3900 ! 4600

I Part of agrieulture /Actif / Added value 6.61 5.65 I

--- .. - -

tv Source : EEC (1978) ...... Vol

tv ~

~

Table 5

Agricultural structure, land-u se and socio-economic categorisation (Ringkobin,Denmark)

Farm structure 0-2 ha 2-10 ha 10-20 ha

Number of farms 216 2039 3964 1.65 % 15.54 % 30.21 %

Mean farm size 29.30 ha Gini coefficient .37 Utilized agricultural area per active farmer 21.58 ha Agricultural added valuefha 228.43 EUR

Production systems STL STH SVF 100 ha 100 ha 100 ha 4834 323 0 93.74 % 6.26 % .00 %

Non-agricultural ! Agricultural ! Total

Added value (105 EUR) 4580 ! 1178 ! 5758 79.54 % ! 20.46 % ! 100.0 %

Active population (100) 846 ! 239 ! 1085 77.97 % ! 22.03 % ! 100.0 %

Added valuel actif person 5400 ! 4900 ! 5300

Part of agriculture fActif f Added value 22.03 20.46

Source : EEC (1978)

20-50 ha +50 ha Total

5707 1196 13122 43.49 % 9.11 % 100.0 %

SAU SCE UGB 100 ha 100 ha 100 5157 1950 4799 100.0 % 37.81 %

Total population 2474

Table 6

Results of analyses for the regions in Germany

Regierungsbezirk System of production Size of holding (ha)

Schieswig-Hoistein Arable-cereals 20,.50 & 50 Hamburg Pigs, permanent crops <2 Hannover Arabie, cattle 2-10 & 20-50 Hildesheim Arabie - cereals < 2 & 2-10 Luneburg Arabie - cereals 20-50 & > 50 Stade Cattle 20-50 Osnabruck Cattle, pigs, arabie 2-10 & 20-50 Aurich Cattle < 2 & 2-10 Braunschweig Arabie, cereals 20-50 & > 50 Oldenburg Cattle, pigs 10-20 & 20-50 Bremen Cattle < 2 & 20-50 Dusseldorf Arabie, cattle, pigs 10-20 & 20-50 Koln-Aachen Arabie, cereals 2-10 & 10-20 Munster Arabie, cattle, pigs 2-10 & 20-50 Detmold Arabie, cattle, pigs 10-20 & 20-50 Arnsberg Cattle 2-10 Darmstadt-Wiesbaden Arabie - cereals < 2 & 2-10 KasseI Arabie, cattle, pigs 2-10 Koblenz Arabie, cereals 2-10 Trier Cattle 2-10 Rheinhessen-pf.altz Arabie, cereals < 2 & 2-10 Stuttgart Arabie, cattle, pigs < 2 & 2-10 Karlsruhe Arabie, cereals <2 Freiburg Cattle 2-10 Tubingen Cattle 2-10 & 10-20 Oberbayern Cattle 2-10 & 10-20 Niederbayern Arabie, cattle 2-10 & 10-20 Oberpfalz Arabie, cattle 2-10 Mittelfranken Arable-cattle 2-10 Unterfranken Arabie, cereals 2-10 Schwaben Cattle 2-10 & 10-20 Saarland Arabie, cereals <2 Berlin Pigs <2 Oberfranken Arabie, cattle 2-10

Söurce: EEC (1978)

The field of survey is confined to holdings which market at least half of their final production and are run by persons who devote at least three-quarters of their annual working time to the business. During the network's first years of operation the field of survey was further limited so as to cover only holdings of five or more hectares, though this limitation as to area did not apply to businesses producing

215

Table 7

Results of analyses for the regions of the Netherlands

·Provinces

Groningen

Friesland Drenthe Utrecht Noord-Holland Zuid-Holland Noord-Brabant Limburg

Overijssel Gelderland Zeeland

Source : BBC (1978)

Table 8

. System of Production

Arabie

Permanent pasture Arabie Permanent pasture Horticulture Horticulture Permanent pasture Arabie

Permanent pasture Permanent pasture Arabie

Size of holdings (ha)

Large (20-50) and very large (> 50) Large (20-50) Average (10-20) Average (10-20) Very small (1-5) Very small (1-5) Small (5-10) Small (5-10) Average (10-20) Small (5-10) Small (5-10) Large (20-50)

Results of analyses for the regions of Belgium/Luxembourg

Provinces System of Production Size of holdings (ha)

Antwerpen Permanent pasture and Very small (1-5) cattle

Brabant Arabie Very small (1-5) Limburg Permanent pasture and Average (10-20)

pigs Luxemburg Permanent pasture and Very small (1-5)

cattle Hainaut Permanent pasture, Average (10-20)

arabie and cattle ' Namur Permanent pasture, Average (10-20)

arabie and cattle Oost-Vlaanderen Arabie and pigs Small (1-5) W est-Vlaanderen Arabie and pigs Large (20-50)

Very large (> 50) Liege Permanent pasture and Average (10-20)

cattle

G. D. de Luxembourg Permanent pasture, Large (20-50) arabie and cattle

Source : BBC (1978)

216

Table 9

Results of analyses for the regions of Denmark

Amt

Kobenhavn Frederiks-borg, Roskilde Vestsjaelland

Storstrom Fyns

Sonderjylland

Ribe Vejle Ringkobing

Arhus - Viborg Nordjylland Bornholm

Souree : EEC (1978)

System of production

Arabie land Cereals Produdion of seeds Cereals and pigs

Arabie Poorly defined

Cattle production

Cattle production Permanent pasture Cattle production

Pig production Cattle production Cattle production Pigs

Size of holdings (ha)

Very large (> 50) Poorly defined Poorly defined Very small «2) and small (2-10) Large (20-50) Very small «2) and small (2-10) Large (20-50) and very large (> 50) Large (20-50) Average (10-20) Large (20-50) and very large (> 50~ Average (10-20) Average (10-20) Average (10-20) Poorly defined

wine, fruit, horticultural produce or olive products, for which no limit as to area has been set. Since 1973, the network has provided information for each of the 9 Member countries.

The latest published results for the network refer to 1977. Nearly 20,000 holdings in 50 Administrative Divisions were studied in 1977. The utilized agricultural area (UAA) of the Community is approximate­ly 94,000,000 ha, thus the farm sample density is 1 per 4700 ha UAA. The farming typology adopted in the network is shown in figure 1, and the distribution of the sample holdings by main type of farming and by country is shown in table 11. The farming typology consists of 29 main types of farming and must be viewed as an important potential information sQurce in the context of an E.E.C. land evalua­tion research programme. There is clearly a need to systematize the farming types against the 1: 1,000,000 Soil Map of Europe. The order­ing of farming type against soil mapping unit could only be achieved through collaborating with the Community Committee for the Accountancy Data Network.

A cursory examination of table 11 indicates the dominance of ruminant production in E.E.C. farming systems. Apart from being a

217

Table 10

Results of analyses for the regions of Ireland

County System of production Size of holding (ha)

Carlow Arable, cereals 20-50 & >50 Dublin Mixed, horticulture <2 Kildare Cattle >50 Kilkenny Cattle 20-50 & >50 Laoighis Cattle 20-50 Longford Cattle 10-20 Louth Cattle, arable, cereals <2 & 2-10 Meath Cattle 20-50 Offaly Cattle 20-50 Westmeath Cattle 2-10, 10-20, 20-50 Wexford Arable, cattle, sheep 20-50 & >50 Wicklow Cattle, sheep 20-50 & >50 Clare Cattle 10-20 & 20-50 Cork Arable, cattle 20-50 Kerry Rough grazing, cattle 2-10, 10-20, 20-50

(milk) ; sheep Limerick Cattle (milk) 20-50 Tipperary N. Cattle 20-50 ' Tipperary S. Cattle (milk) 20-50 Waterford Cattle (milk) >50 Galway Rough grazing, cattle, sheep 2-10 & 10-20 Leitrim Cattle 2-10 & 10-20 Mayo Rough grazing, permanent 2-10

pasture, cattle Roscommon Cattle 2-1.0 & 10-20 Sligo Cattle 2-10 & 10-20 Cavan Cattle, pigs 10-20 Donegal Rough graiing, cattle, sheep <2 Monaghan Cattle, pigs 2-10

Source: EEC (1978)

valuable information source on farming typology in the E.E.C., the network effectively constitues a data bank on the many attributes of the farming systems practised. These attributes include : (i) area of holding, (ii) labour force, (iii) farm capital (livestock, equipment and working), (iv) land use, (v) livestock numbers, (vi) value of production per ha or per animal, (vii) input per ha (U.A.A.), and

218

MAINTYPE I SPECIFIC TYPE I SPECfALIZATION

1. ArabIe (excluding forage crops)

II . Permanent erop production

IlI.Gra~ing stock

N.Pigs and poultry

V. No predominant type

concentrating on

combined with

concentrating on

combined with

concentrating on

combÜied with

concentrating

general agriculture (A)

horticulture (B)

general agriculture and horticulture (A) and (B) permanent crops grazing stock pigs and poultry

fruit {C)

vines (0)

olives (E) two or more of these specific types (C, 0, or E) arabIe eropping grazing stock pigs and poultry

cattle (F)

sheep and goats (G) cattle , sheep and goats (F and G) arabIe eropping permanent crops pigs and poultry

pigs (H)

on poultry (K)

combined with

pigs and poultry (H and K) arabIe eropping permanent crops grazing stock

not subdivided

~~;~er cereals subdivided other produets of gen. agr.

not specialised not subdivided

!market gardening outdoor market gardening under glass

subdivided floriculture outdoor floriculture under glass vegetables as a field erop mushrooms not specialised

not subdivided

ifreSh fruit dried fruit

subdivided citrus fruits not specialised

not subdivided

{

tabIe grapes wine of controled vintage

subdivided ordinary wine not specialized

not subdivided

fmilk

subdivided meat not specialized

not subdivided

~reeding

subdivided fattening not specialised

not subdivided

taYing hens subdivided broilers

non-specialised

Source From Accountancy Data Network for the EEC, Results 1977, Brussels 1979

Fig. 1.

Classification of farm holdings according to farming type

219

Table 11

Breakdown of returning holdings by type of farming and by country (1977)

Main type of farming D F I B L NL DK IRL UK EEC

No. %

Gen. agric.-horticult. 1 11 80 :4 4 2 7 109 0.6 General agriculture 162 321 808 38 281 150 2 240 2002 10.1 Horticulture 1 127 442 95 325 5 44 1039 5.3 Arable-permanent crops 1 17 280 4 1 303 1.5 Arable-grazing stock 161 276 456 40 25 45 6 84 1093 5.5 Arable-pigs and poultry 61 5 58 11 4 74 1 11 225 1.1 Perman. crops-arable 1 45 262 2 2 312 1.6 Miscel. perm. crops 4 72 31 107 0.5 Fruit 2 157 587 35 46 1 828 4.2 Vines 69 316 738 1123 5.7 Olives 260 260 1.3 Cattle 959 1309 1064 276 62 401 306 680 940 5998 30.4 Milk 520 737 630 182 27 380 148 269 475 3368(17.1) Meat 49 375 167 20 8 8 335 355 1317 (6.7) Non. spec. cattle 390 197 267 74 35 13 150 76 111 1313 .(6.6) Perman. crops-pigs & poultry 1 30 1 1 33 0.2 Grazing stock-arable 550 518 545 69 8 24 131 26 122 1993 10.1 Grazing stock-perm. crops 2 46 252 2 1 1 304 1.5 Cattle, sheep & goats 1 23 18 1 4 1 8 15 70 0.4 Perm. crops-grazing stock 45 199 1 246 1.2 Sheep, goats 25 60 2 22 127 236 1.2 Graz. stock-pigs & poultry 596 141 34 95 16 75 270 9 30 1266 6.4 Pigs & poultry-graz. stock 163 11 48 16 8 131 19 396 2.0 Pigs & poultry-perm crops 23 1 2 26 0.1 Pigs & poultry-graz. stock 403 56 14 78 14 59 160 3 19 806 4.1 Pigs and poultry 1 1 4 4 1 11 0.1 Pigs 241 66 32 74 128 246 1 26 814 4.1 Poultry 2 28 9 5 40 19 5 107 0.5 No dominant main type of 1 3 34 1 39 0.2 farming

Total { Number 3378 3552 6405 843 100 1471 1549 758 1691 19747 % 17.1 17.9 32.4 4.2 0.5 7.4 7.8 3.8 8.6 - 100

Source : Farm Accountancy Data Network for the E.E.C. Results 1977. Brussels 1979.

(viii) gross product, gross farm income and net farm income per ha (U.A.A.).

The disaggregation of these agricultural use factors according to the soû mapping units is fundamental in the establishment of present land-use/productivity/soû type relationships. The 1977 report includes

220

summary tables of the following data for each of the 50 Divisions of the E.E.C. adopted for the purposes of the Network : (i) income distribution by system of farming and holding size, (ii) income distribution for cattle holdings according to their special­ized category (milk, beef, milk + beef) and holding size, (üi) gross production/ha for cereals, potatoes and sugar-beet by holding size, and (iv) milk yield (kg/year/cow) according to herd size.

4. COMMUNITY SURVEY ON THE STRUCTURE OF AGRICULTUR­AL HOLDINGS

The most recent Community Survey for the year 1975 was publish­ed in 1979 (Eurostat, 1979). It involved the collection of some 100 items of information by Member States for each of some 900,000 agricultural holdings (15 % sample) surveyed by the Statistical Services of each country and the collation and publication of the results of the Survey by the Statistical Office of the European Communities (SOEC). Table 12 sets out the number of survey holdings in each Member State. .

Table 12

Number of holdings in survey

Country Number of holdings

F. R. Germany 100,460 France 143,503 Italy 233,667 Netherlands 162,594 Belgium 138,067 Luxembourg 1,737 United Kingdom 29,277 Ireland 37,970 Denmark 20,135

Eur-9 867,410

Souree : Eurostat (1979)

This exhaustive survey constitutes a highly valuable data base relating to the structural component of farming systems. The items covered include : (i) geographic situation of the holdings; (ii) legal personality of the holding; (üi) type of tenure (including agricultural and area utilized);

221

(iv) management of the holding and manager's education; (v) land-use, resp. subdivided into arabie land (erop specified), per­manent pasture and meadow, permanent crops and other land (wood­land, unutilized agricultural area); (vi) livestock ; (vii) mechanization; and (viü) farm labour force.

One of the six volumes of the results of the survey is devoted ex­clusive1y to land use. The survey results . are published at levels corres­ponding to the Community, Member State and Region (Survey Dis­trict). The results at regionallevel apply only to France, Germany, Italy and the U.K. (62 regions).

5. FORESTRY LAND-USE

F orests cover 31 million ha or 21 % of the totalland area of the E.E.C. This is about the same as the area occupied by cereals and one third of the area devoted to farming as a whoie. The total negative trade balance for forest produets amounts to 8000 million Units of Account per year. Annual production of wood is about 80 million m3

and this is expected to rise under existing national forestry policies by about 1 % per year which is approximately half as fast as demand. Against this background forest land-use must be considered an import­ant element in any proposed Community land evaluation research programme.

Timber expansion is most likely to occur in the areas designated as being less favoured. These areas extend over 36 million ha. Land evaluation research has a major role to play in identifying those areas best suited to afforestation and those areas which should continue in farming or be upgraded for agricultural use (stock farming). Clearly, land evaluation is fundamental to the formulation of a forestry/agri­culture land-use policy for the E.E.C.

Details of the structure, ownership, and management of the Com­munity's forest estate are given in table 13. State forests are generally in fairly large units and are efficiently managed. Private forests on the other hand are highly fragmented. All except about 50,000 of the 3 million woodland owners in the Community have less thari 50 ha. Very few woodland owners, most of whom are farmers, dep end on forestry for their income.

6. CROP AND LAND-USE INVENTORIES IN E.E.C.

Comprehensive national statistical enumerations of agricultural,

222

N N Vl

Table 13

Forest area distribution aeeording to ownership and management (000 ha)

Forest Area Ownership Produetive high forest

State Total as % State Other Private Conifers Broad- Total of Publie leaved land bodies area

Belgium 615 20 75 220 320 280 260 540 Denmark 470 11 135 50 285 260 140 400 Germany 7,200 29 2,250 1,800 3,150 4400 2000 6400 Franee 13,950 25 1,720 2,480 9,750 4400 2750 7150 Ireland 330 4 250 - 80 240 50 290 Italy 6,300 21 350 2,150 3,800 1100 1600 2700 Luxembourg 85 32 5 30 50 25 40 65 Netherlands 310 8 85 50 175 155 50 205 U nited Kingdom 2,020 8 880 - 1,140 1200 300 1500

EEC 31,28'0 21 5,750 6,780 18,750 12060 7190 19250

Souree : Commission of the EEC Forestry Poliey in the European Community COM (78) 621 Brussels 1978.

Other

75 70

800 6800

40 3600

20 105 520

120:30

Table 14

Surveys of farm land - type and method of survey

Coun- Type of survey Survey method Field Lower threshold Coverage try

personal formal r 1 )

A H of horti-cultural a.reas

B full enumerator request AH none indivi-dually

DK full by post request AH 0,5 ha 3) none indivi-dually

D to tal! sam ple enumerator request AHF 1 ha or none only equivalent groups production value 4)

EPEXA permanent interviewer request A threshold values groups

F sample

SAA full report report all holdings indivi-

IRL

I

L

NL

UK

sheet dually

to tal! sam ple interviewer survey log AHF none summary

full report report all holdings indivi-sheet dually

full enumerator request AH 1 ha none only groups

full interviewer request AH 10 sbe indivi-dually

full by post request AH 40 smd indivi-dually

1) A = agricultural holdings, H = horticultural holdings, F = forestry holdings 2) G = gross, N = net 3) plus holdings of under 0.5 ha with a value of production equivalent to that of

badey on half a hectare 4) Plus holdings and total areas of under 1 ha whose natural production units are

equivalent to at least the average value of annual marketable agricultural produce from 1 ha of land used for agriculture.

Souree : H. Hix, Doe D/PE/10S Statistical Office of the European Communities Agricul tu ral Statistics.

224

Gross or net

principle 2)

N

N

N

N

G

G

N

N

N

G

Coun-try

B

DK

D ·

F

IRL

I

L

NL

UK

Table 15

Surveys of farm land - coverage of forest and non-agriculturalland

Title of survey Type Date Periodicity of data on 1)

Reference Reference forest land

date or period on agricul-date of tu ral hold-survey ings

Recensement agri': A 15 May Periodical cole et horticole

Landbrugs- og A frrst Frl. Periodical gartneritaelling in June

Bodennutzungs- B January- Annual haupterhebung May

EPEXA C Nov/Oct. None

Statistique Agri- C calendar cole Annuelle year

Agricultural A from Annual Statistics, 1 June Enumeration

Ripartizione della C Nov./Oct. superficie agraria e forestale ... 2)

Landwirtschaft- A 15 May Annual liche Zählung

Landbou wtelling A May Periodical

Agricultural and A first Annual Horticultural weekday Census in June

1) A = multi-sector cen~us, B = single-sector (farm land) survey, C = ex post (annual) determination

all forest land

10 yrs

10-20 yrs

Annual

Annual

Annual

Annual

15-20 yrs

(annual)

15-20 yrs

Summary recording non-agricul-turalland

no

belonging to holdings

belonging to holdings

no

yes

yes

yes

belonging to holdings

belonging to holdings

belonging to holdings

2) Full title : Ripartizione della superficie agraria e forestale per forma di utilizza­zione eper coltivazione

Source : H. Hix, Doc D/PE/105. Statistical Office of the European Communities Agricultural Statistics.

225

horticultural, forestry and non-agriculturalland uses are carried out by the appropriate statistical authorities in each Member State. Two main types of survey are completed. Tables 14 and 15 compare the ways in which the results are obtained and give a rough outline of national differences in concepts and survey methods.

In seven of the nine states a survey of agriculturalland-use is made in spring while in two - France and Italy -- data are collected retro­spectively af ter the end of the crop or calendar year. In six Member States, agriculturallanduse is recorded together with surveys in other fields of agricultural statistics in the form of an annual census of agri­culture and horticulture. The Institute of Economic Research of the University of Groningen, the Netherlands has completed a data bank on regional agricultural data for the nine E.E.C. countries (deBoer and Jacobs, 1979). The data are derived from the National Agricultural Censuses described above. The same data are also stored by the E.E.C. in the 'CRONOS' system located at the SOEC in Luxembourg. DeBoer and Jacob (op. cit.) assert that most of the stored data are comparable over the various regions of the E.E.C. However, because of a lack of a standardized approach to definitions of some land-use enterprises, there . may be bias in regard to rough grazing~, vegetables, orchards, total agricultural area and permanent grass.

7. LAND-USE MAPS OF EUROPE

7.1. INTERNATIONAL LAND-USE MAPS

The maps in the World Atlas of Agriculture published by the Istituto Geografico De Agostini, Novara in 1969 are strictly cartograms based on available statistics. The maps which include every country in Europe are on a scale of 1:2,500,000. These maps show approximate geographic locations of different categories of land utilization within administrative limits. The maps are constructed from data available for the basic administrative unit chosen appropriately for each country. The maps show the principal categories of land-use within the limits provided in each case by the scale. An attempt was made to locate such categories within each administrative unit. Only those categories which occupy an area on the map of greater than 2 mm 2 (whatever the scale) we re located in this way. Smaller areas of any one category are grouped together and are shown by a separate symbol. This method results fr om the need to represent the location and extent of the categories as accurately as possible within the limitation imposed by the scale. The following land-use categories we re delineated in most of the E.E.C. countries and represented by an appropriate colour

226

scheme : (i) arabie land; (ii) meadows and permanent grassland; (iii) fruit trees, vineyards, bushes and orchard land; (iv) market gardens, gardens and nursery gardens; (v) woods and forest; (vi) rough grazing land; (vii) non-agriculturalland; and (viii) inland water.

wh ere fruit trees, vineyards, market gardens were less than 1000 ha in extent they were depicted symbolically by a circle.

A second land use map of Europe depicting the dominant land-use forms in the 1970's was also published on a scale of 1: 2,500,000. This work was carried out within the research programme of the Institute of Geodesy and Cartography of the National office of Lands and Mapping - M.E.M. Hungary under the auspices of the World Land Use Survey Commission, International Geographical Union. The map was co-ordinated by Csati Erno, Budapest.

The following major land-use categories are delineated : (i) per'­manent crops; (ii) mainly productive forests and woodlands ; (iii) other forests and woodlands; (iv) temporary crops; (v) improved grasslands ; (vi) unimproved grasslands; (vii) wastelands or zones of extra low productivity; (viii) built-up areas; (ix) inland waters; and (x) regions of flower production.

The following land-uses are delineated in the permanent cr op cate­gory : apples, olives, pears, stone fruits, mixed orchards, citrus fruits, nuts, raspberry, strawberry.

The mainly productive forests and woodlands as well as the other forests and woodlands are subdivided into conifers, deciduous and mixed categories. A system of symbols is superimposed on the basic colour to indicate. the dominant tree type. Temporary crops as a land­use class are defined as 'arabie lands of constant use , and/or temporary fallows : on at least . 50 % of the territory grain crops'. Im proved grasslands are defined as areas occasionally intersected with small plots of arabie land, under constant human intervention (drainage, irrigation, reseeding, etc.). They are subdivided into wet and dry. The wet grass­lands occur under an annual precipitation over 500 nlm : theyare generally of high quality and partly meadow. The dry grasslands occur under an annual rainfall below 500 mm; they are generally irrigated. The unimproved grasslands category is also subdivided into wet and dry and includes alpine meadows.

7.2. NATIONAL LAND-U SE MAPS

In addition to the above two European Land-Use Maps, the follow­ing national maps are worthly of note :

227

7.2.1. United Kingdom

The Second Land-Use Survey was inaugurated in 1960 under the direction of Dr. A. Coleman. The maps which are published on a scale of 1 :25,000 involve two levels of classification; 13 major land-use groups represented by colours and sub-divisions represented by conven­tions. One thousand two hundred (1200) maps have been published while the 1: 10,560 field sheets covering the entire country are on file in London. A comprehensive explanation of the survey is available (Coleman & Maggs, 1968).

7.2.2. Italy

The Istituto Nazionale di' Economica Agraria published a map en­titled 'Carta della Utilizzazione del suolo d'Italia' (Antonietti and Vanzetti, 1961). A second map at scale 1 :200,000, has been published by the Italiano Consiglio Nazionale delle Richerche (Roma, Piazzole delle Scienze). This is a major work prepared by the co-operation of the Italian Cadastral Organization and of the Touring Club Italiano (Vanzetti, pers. comm.). The 1:200,000 land-use project commenced in 1950 and was completed in 1968; there are 26 sheets in all.

The categories of land utilisation represented on the maps (scale 1:750,000) of Antonietti and Vanzetti (op. cit.) are as follows. 1. Arable land, with or without trees and shrubs, where trees and

shrubs do not occupy more than 5 % of the total area. 2. Arable land with trees and shrubs, chiefly vines, where vin es and

other trees or shrubs are economically important and occupy an important part of the total area, but such that they cannot be classed as vineyards.

3. Vineyards, where vines are economically the most unportant culti­vation.

4. Arable land with trees and shrubs, chiefly olives, where olives and other trees and shrubs occupy fr om 5-50 % of the total area.

5. Olive groves, where olives occupy more than 50 % of the total area. 6. Orchards and other trees and shrub planted land where trees and

shrubs occupy more than 50 % of the total area ; usually fruit trees in northern and central Italy and citrus in the south and on the islands.

7. Market gardens, gardens and nursery gardens, where the land is used permanently by these cultivations and by flower cultivation.

8. Meadows and permanent grassland, where permanent pasture is grown and where trees do not occupy more than 5 % of the total area; pastures are mowed at least once per year for hay.

228

- ---- ---------------------------

9. Woods and forests, where wooded land occupies > 50 % of the total area and where forest products are economically significant.

10. Uncultivated agriculturalland and areas permanently and solely or almost exclusively devoted to natural pasture or other uncult­ivated products; pasture is utilized only for grazing. Trees where they exist do not occupy more than 5 % of the total area.

11. Non agriculturalland and areas not used for agriculture , including inhabited centres, roads, rivers, lakes, glaciers, ponds and deserts.

According to Antonietti and Vanzetti, (1961, op.cit.) the land-use maps are cartograms and within the limits of the administrative unit or commune; they must be regarded as equivalent to statistical dia­grams! The categories of land utilization are represented according to the areas which they occupy. The maps show the geographicallocations of the land-utilization categories witliin the limits of each administra­tive unit; moreover , they are only valuable for units covering an area of at least 450 ha.

7.2.3. Ireland

The most comprehensive cartographic documentation of lrish agri­culturalland-use is included in the Atlas of lreland, published by the Royal lrish Academy in 1979. The thematic maps which are published on a sc ale of 1 :3,000,000 are based on statistics published by the Central Statistics Office for administrative units which may be a County or Rural District. The following coloured maps are included in the atlas and refer to the year 1970 . 1. Average area of crops and pasture per holdings (Unit él:rea = County). 2. Crops and pasture as a percentage of total area (Unit Area = Rural

District). 3. Cows, other cattle, sheep and horses per 100 ha crops and pasture

(Unit area = Rural District).

A map of scale 1:1,250,000 shows the distribution of State Forests in 1972. (Private forestry accounts for only 24 % of the lrish forest area).

Maps of scale 1: 250,000 showing the distribution of the major tillage crops in lreland and also grazing livestock density patterns have been prepared by Lee (1970), and are stored in the National Soil Survey headquarters. These maps are based on an analysis of census data for the smallest administrative unit in the country, which is the District Electoral Division.

229

7.2.4. Netherlands

Traditionally land use information in the Netherlands was document­ed through a questionnaire survey covering each of the 840 municipal­ities. However, recently the questionnaires were replaced by maps (1:10,000) on which the land use of each municipality is plotted (Netherlands Central Bureau ofStatistics, 1980). In addition to the detailed municipality maps a nationalland-use map on a scale 1 :400,000 is available. This map is published as three double sheets in atlas form (DeGrote Bosatlas : WoltersNoordhoff, Groningen). The legend for the map includes : arabie land, horticulture, grassland, heath­land, beach and coastal dunes, inland dunes, important industrial and harbour areas, works for acceleration accretion on coastal marches (landaanwinningswerken), canal types (five) , sand bars and tidal flats exposed during low tide, depth classes of the sea floor (four).

There is also a 1: 200,000 land-use map of the Netherlands (Derde Wandkaart van Nederland, Wolters-Noordhoff-Groningen) and a 1 :600,000 scale 'Types of Farming' map (Atlas of the Netherlands, 1967).

7.2.5. Denmark

Kampp (1959) divided Denmark into 7 agro-geographical regions, principally on the basis of parish statistics of the total yield per hectare of a series of crops, together with statistics of wheat-barley areas as a percentage of the rotation area. Kampp (1970) further analysed the spatial pattern of Danish agriculture such as productivity, crop distribution and cattle density and presented his results both in tablliar form and through the use of quantitative dot maps.

7.2.6. Belgium

A comprehensive map coverage of Belgian land-use is available. These maps which are on a scale of 1: 25,000 have the added advantage of showing contours with intervals of 2.5 metres. Approximately 225 sheets cover the entire country. The land-use maps which were publish­ed by the Belgian National Geographical Institute are based on aero­photogrammetrical surveys and depict the land-use pattern of 1970. The map shows the distribution of the following land use categories :

. sand dunes, heath or moor, meadow, high foliated trees and copse, conifers, poplars, orchards, tree nursery or osier beds, and farming land.

The Belgian communications network (roads and water classifica­tion),built-up areas and other non-agriculturalland-use factors are also depicted.

230

7.2.7. France

Flatres (1976) reported that land-use mapping in France has suffer­ed from the multiplicity of different approaches and scales employed by the various institutions, university and governmental, which have attempted it. Some of the approaches are illustrated through a few case studies. For example, thematic land-use maps have been prepared for the Languedoc-Rousillon regions which accounts for 30 % of France's vine area. The maps show (i) percentage of the total agricul­tural surface occupied by the vine, (ii) yields, (iii) structure of the vine producing holdings and (iv) the distribution of vineyards. Dufour (1972) used a method of graphs and histograms to summarize types of farm production in the context of the Sarthe departement of western France. Grosso (1976) made use of the material of the 1970 Statistical enquiry on French agriculture to map the distribution of such crops as vegetables, market-garden crops, fruit and vine in the Com tat region in Sou th -east F rance. Guermord and Massias (1974) devised a series of land-u se combinations from the French agriculture censuses of 1955 and 1970.

France has a national agriculturalland-use map entitled "Utilisa­tion Agricole du Sol en France". The map is based on the record of land use for each land registry district in France. The map is coloured and the scale is 1: 1 ,400,000. It was published by the Centre National de la Recherche Scientifique under the direction of Prof. A. Perpillou. The map legend is as follows :

Arabie Land >96 %

Pasture-forage

Vines

Fruit trees

Vegetables Woods and forest

96-76% 76-56%

>45% 45-35% 35-25%

>31% 31-22% 22-13%

>39% 39-27% 27-15%

>7% >50%

50-30% Moors - uncultivated > 6 8 %

68-36% Several dominant uses

231

8. FARMING TYPOLOGY IN EUROPE - AN INITIAL PERSPECT­IVE

The World Atlas of Agriculture published by the Istituto Geografico De Agostini, Novara, which was referred to earlier, is a valuable in­formation source on farming typology. However, the types of farming maps included in the atlas are of extremely small scale, very general­ized and refer to 1960. Because of the rapid developments in agri­culture since then, the máps may now be out of date. Nevertheless, they have an important utility in providing a rapid initial insight into spatial patterns in farming typology in the E.E.C.

Brief descriptive details of farming types in a number of Member States were abstracted from the Monograph accompanying the World Atlas of Agriculture and are set out here to provide an initial farming typology perspective.

8.1. ITALY

The various types of farming in Italy we re classified into 9 categories which were established according to the predominance of one particular product or group of products in the gross saleable production. Each category consisted of either one or several related farm types and only in those cases where none of the principal products constituted two-thirds of the gross output were unrelated types of farming included within the same category. The categories were as follows : (1) fruit ánd vegetables, soft fruit and citrus fruit production; (2) vines, olives, other tree crops and intensive mixed farming; (3) extensive mixed farming with pasture ; (4) cereals with livestock and vin es or industrial crops; (5) intensive dairy production ; (6 ) intensive beef production ; (7) hilllivestock production; (8) mountain livestock production with forestry and pasture ; and (9) cereals, sheep and other livestock.

Livestock production and cereal cultivation were the two most im­portant types of farming.

8.2. UNITED KINGDOM

In the small-scale map of types of farming in the World Atlas of Agriculture both the dominant enterprise and important subsidiary enterprises, where occurring were indicated. Many minor enterprises and many smalllocalities, however distinctive, were inevitably ignored.

In most of the areas shown as 'Livestock Rearing~ climatic conditions restrict farming to the breeding of hardy sheep, though on eastern margins of the uplands hardy cattle are often reared and may be more important. The sheep farms are generally large in area, although they

232

are of ten small as farm business and consist largely of rough grazing. Horticultural crops provide the distinctive characteristics of the

areas marked 'horticulture' , although they occupy less than half the land and there are generally many holdings of other types. East Anglia and parts of eastern Scotland are the chief areas where the growing of cash crops (other than fruit and vegetables ) is most strong­ly developed, although both small and large livestock are also import­ant. In Lincolnshire, the East Riding of Y orkshire, and most of the eastern coastlands of Scotland sheep and cattle play a more import­ant role, although the emphasis is still on crop production. In areas marked 'Livestock Rearing and Fattening' farming is of ten concerned with the finishing of sheep and cattle, but in Herefordshire and Northamptonshire types of farming are nlore mixed than in northern counties.

In most of the remaining areas, dairying is the major enterprise, although the degree of dominance varies greatly and most of the areas in which other enterprises are common could also be classified as areas of mixed farming. In the Belfast region, in Ayrshire, in Cheshire, Derby, and Stafford, in most of lowland Cardigan and Carmarthen, and in Somerset, Wiltshire and Dorset dairying is by far the most important enterprise and these are sometimes referred to as the main dairying areas. Around the uplands, as in northern England, Wales and southwest England, livestock rearing and some fattening are also practized, while on the chalklands and the Cotswolds dairying is associated with arabie farming and cash cropping, particularly the mechanized growing of cereals. In much of the country around London and the southern Pennines, other subsidiary enterprises are common, especially pigs, poultry and vegetables.

A small-scale coloured type of farming map based on agricultural census data was published in 1968 (Church et al, 1968). Definitions of the farming typology shown on the map are given in table 16.

The country was subdivided into 10 km grid squares. Each square was classified into farming types as shown in table 16 according to the estimated proportions of the total S.M.D. which were on farms of the six types A, H, D, L, P, and M.

8.3. FEDERAL REPUBLIC OF GERMANY

Five types of farming were distinguished. The first type, dairy farm­ing, is to be found mainly in the north-western regions, namely in the western part of Schieswig-Hoistein and of Lower Saxony as weIl as in the plain of Westphalia. Cattle rearing for both milk and beef produc-

233

Tahle 16

Definitions of area farming types

Area types Area composition

Area with more than half S.M.D. on holdings of type

Arable General arabie A Arabie with horticulture A + H (A>H) Horticulture H Horticulture and general arabie H +A (H>A)

Livestock Dairying D Beef cattle and sheep (rearing and fattening) L Pigs and poultry P Mixed livestock mainly dairying D + L +P (D>L or P) mainly beef cattle and sheep D + L + P (L> D or P) mainly pigs and poultry D + L + P (P> D or L)

Mixed Mixed farms M

Areas not conforming to above criteria but with

Arab Ie with livestock A+H>D+L+P Livestock with arabie A:.rH<D+L+P

Source : Church et al., 1968.

S.M.D. = Standard Man Days (Measure of size of business) A = General Arable eropping H = Horticulture D = Dairying L = Beef cattle and sheep - livestock rearing and fattening P = Pigs and poultry M = Mixed

Area type (letter code on map legend)

A AH H HA

D

L P

d I

P

M

M(A) M(L)

tion is large1y predominant, and dairy produets are the greatest souree of income' in agriculture.

The second type is based on mixed. production, being the rearing of animals for milk and meat and cereal and potato growing. It is practized in eastern Schleswig and in a large region including northern parts of Lower Saxony, eastern Hessen and a large part of Bavaria.

234

This type is also found in all parts of the country, whereever aspecific type of farming is not predominant.

The third type of farming is substantially similar to the second one, but with a market tendency to the cultivation of sugar beet and occasionally of some other industrial crops such as hops. I t indudes the middle and southern regions of Lower Saxony, parts of North Rhine and of the Palatine as well as South Hessen and North Bavaria.

The fourth type is based especially on vine growing and partlyon the cultivation of tobacco. It is practized along the course of the Rhine and Mose! rivers; in these regions farms are generally of small proportions.

The fifth type is practized in the southern part of Baden-Wurtem­berg and in southern Bavaria, where the alpine environment is pre­dominant. Breeding of cattle, in the western parts also of sheep, to­gether with the exploitation of forestal resources, constitute the basis of agricultural production.

8.4. DENMARK

Five farming types were distinguished. In western Jutland, rye potatoes and livestock (pigs and dairying) are important. In southern Jutland cereals and fodder crops are important and the breeding of cattle and sheep. In Eastern Denmark as well as in many areas of the islands (North Zealand), livestock breeding is of great importance to­gether with badey, fodder root crops. In the other are as of the islands livestock breeding is equally intensive in addition to the cultivation of industrial crops. Over most of Jutland, Vendsyssel and in North-west Jutland cereals and fodder root crops are the prevailing crops.

8.5. NETHERLANDS

Four main types of farming were distinguished : (1) arabie farming with a small percentage of the farm area under permanent grass; (2) grass farming with little arabie cropping; (3) arable/grass farming (arable dominant); and (4) mixed farnüng with predominance of grass. Arabie farming is encountered partly in the South-west and North-east of the coastal regions and in the IJsselmeerpolders and partly in some inland polders. It is also dominant in the redaimed peatlands in Drenthe and Groningen. Grass farming for dairying is encountered in a wide belt of the coastal regions where soft peat and oid marine day soils, hard to till, predominate; this is a zone trending SW-NE com­prising large parts of Zuid-Holland, Utrecht, Noord-Holland, Friesland and some parts of Groningen and Overijssel.

235

The mixed types of farming are of ten combined with some form of horticulture, generally fruit growing, such as in the river day basins of Gelderland and in the loess regions of Limburg. Mixed farming with permanent grassland predominating over the ploughland is typical for the sandy regions of the inland provinces. Some mixed farming is also encountered in the coastal regions, though less frequently than the pure types of farming are.

The predominant type of farming on more than half of the total farm area is grass/ arable and grass/ arable/ fruit, followed by arable and arable/grass farming on more than one-fourth, by grass farming on nearly one-fifth and by market gardening on only a small percentage of the total farm area.

8.6. FRANCE

Few regions are highly specialized. There are some regional mono­cultures, as in the Languedoc plain which holds the large st vineyard area in the world. In ComtatVenaissin, fruit and vegetable specializa­tion is almost as high, while in Roussillon vines are cultivated as well as fruits and vegetables. In the Channel regions, cattle production is highly important. Animal husbandry also predominates in Flanders, in the Boulonnais and on the North Sea coast, as weil as in Thiérache.

From Cambresis to the forest of Orleans, rich alluvial deposits con­tribute to the most industrialized methods of cultivation in France. Agriculture, essentially based on cereals and sugar beet, is highly mechanized. Milk cows and sheep are also raised. These large estates (200 to 400 hectares in Soissonnais, Valois or Brie), though smaller than in Beauce, are highly capitalised and employ many agricultural labourers.

Farming in the west is in contrast with this capitalistic form of agriculture and the natural unit is the family farm, where animal hus­bandry and crops are combined, either being the dominating element depending on the nature of the soil. Animal husbandry predominates on the granitic soils which give good grasslands (Bas Maine, V endee) and crops on the rich soils of Haut Poitou and in the Rennes and Chateaulin basins. Some areas have become highly specialized, such as the tiny farms of Tregorrois and of the Leon plateau on the northern coast of Brittany which devote themselves almost exdusively to early vegetables and fruits, favoured by the mild dimate. In the valleys, particularly in Val de Loire, a more varied form of agriculture is practised than on the plateaux where vegetable crops and the vine dominate.

236

The southwest is even more diversified, and the cultivation of maize is important. The vine and fruit trees occupy part of the valleys, but even in the Bordelais, they cover less than lOper cent of the land.

In the South-east th ere is no uniformity of cultivation. The plateaux of Haute Saone combine crops and animal husbandry in a non-inten­sive system which gives poor yields, while the Cote de Bourgogne shelters high quality vineyards and animal husbandry predominates on the plain lying on the Saone-Rhone axis.

8.7. lRELAND

The agricultural regions of Ireland have been delimited by Gillmor (1967). He recognized seven regions with certain subdivisions : ( 1) western small farm fringe; ( 2) southern dairying region; (3) northern dairying belt; (4) western grazing region; (5) midland grazing region; (6) Leinstel:" arable.:livestock region; and (7) eastern mixed agriculture area.

In the western small farm fringe difficult physical conditions and small farm size prevail with cattle and sheep production being the dominant enterprise and economic returns are low. The major feature of the southern dairying region is that over 85 % of farms supply creamery milko In parts of the region, cattle rearing and arabie farming are also significant. In the northern dairying belt, dairying is combined with store cattle rearing. Cattle and sheep production is the mainstay of the Western grazing while on the Midland Grazing Region there is a definite concentration on cattle production. Farm 'size is bigger and land quality is superior to the Western Grazing Region. Throughout the Leinster Arabie - Livestock Region cash cropping is significant. The city of Dublin is located in the Eastern Mixed Agriculture Area and has astrong influence on farming systems. Dairy farms are w'ide­spread, also market gardeiüng and horticulture and cattle and sheep production.

8.8. BELGIUM

A comprehensive regional analysis of Belgian agriculture has been carried out (Tambuyzer, 1971). For instance, Antwerp province in­cludes three regions : the Polders, the sandy region and the Campine. The Polders and the sandy region consist of small farms, engaged in production of feed crops for livestock (beef in the Polders, nlilk in the sandy region). Horticultural production is significant. The Campine region specializes in milk and fat calf production and also pigs and poultry. Liege province comprises five regions: the alluvial, pasture,

237

the high Ardennes, Condroz and the Famenne. In the a:11uvi~l-Condroz regions, production is base.d on large-scale erop production and cattle. In Condroz and Famenne, cattle p~oduction is expanding and is orientated towards dairying. The pasture and high Ardennes regions specialiZe in dairy production.

Studies of agricultural ev:Olution have been carried out in Flanders (Foutrein, 1975). Maps showing changes in "the proportion of land devoted to crops and livestock were prepared demonstrating a trend towards an increased specialization.

9. FARMING SYSTEM AND LAND UTILISATION TYPOLOGY IN RELATION TO EEC RESEARCH ON LAND RESOURCE EVALUATION

This exploratory study which is not exhaustive has endeavoured to collate various information sources with a view to providing an initial insight into farming systems and land utilization types throughout the EEC. It is hoped th at it will stimulate thought on : (i) the function and need for such information in a land evaluation

context; (ii) the desirability of providing data on the various attributes of land

utilization types as laid down by the framework for land evaluation (NN, 1977);

(iii) the possibility of developing a less rigid typology for land evalua­tion that than proposed by Beek (1975 & 1978) against the back­ground of the EEC 1: 1 million soil map;

(iv) the typology required for land evaluation programmes based on soil maps of scale 1:50,000 to 1:1,000,000;

(v) the need for a definitive project on land utilization types in the framework of the EEC research programme on land resource evalua­tion.

Clearly there is a sizeable data pool relating to farming systems and land utilization types in Europe. If it is considered land utilization typing is an integral part of the European land resource evaluation research programme, then there is an urgend need for further sys­tematic study. In the final analysis farming systems throughoutmost of the EEC can be sim plified iI?-to four classes :

(i) perennial tree or shrub corps (ii) tillage crops (annual)

(iii) grazing or grassland (pasture and ruminants) (iv) grazing and ti~~age alternating.

238

The questions are (i) what level of refinement of these and (ii) what level of information on the attributes of the systems are necessary in the context of the EEC research programme.

REFERENCES

Antonietti A. & Vanzetti C., (1961). Carta delle utilizzazione del suelo d'ltalia. Istituto Nazionale di Economia Agraria, Feltrinelli Editore, Milano, 1961, 82 p.

Beek K. J., (1975). Land utilization types in land evaluation. Soils Bull. FAO, Rome, 29:87-106.

Beek K.J., (1978). Land evaluation for agricultural development. International Institute for Land Reclamation and Development, Wageningen, Publ. No. 23, 333 p.

Church B. M., Boyd D. A., Evans J. A. & Sadler J. 1., (1968). A type of farming map based on agricultural census data. Outlook on Agriculture 5(5) :191-196.

Coleman A. & Maggs K. R. A., (1968). Land-use survey handbook. Kings College, Strand, London WC2, 32 p.

Commission des Communautés Européenes, (1978). Situation et évolution structurelle et socio-économique des régions agricoles de la Communauté. Informations sur tagriculture, Nos. 52, 53, 54.

de Boer T, & Jacobs H., (1979). Guide to the agricultural data collected for the regions of the countries of the E.C. 1950-1973. Institute for Economic Research, State University, Groningen. The Netherlands.

Dufour J., (1972). Graphical depiction of farms in the Sarthe, western France. In : Contemporary Geographical Thought in France : Essays offered to Prof. A. Meynier. Presses Universitaires de Bretagne, Saint-Brieux: 493-513.

Eurostat., (1979). Community survey on the structure of agricultural holdings 1975, Vols. I-VI. SOEC Luxembourg.

Flatres P., (1976). Land-use maps in Western Europe - The example of France. Geographica Helvetica, 31(1) : 7-12.

Foutrein c., (1975). Flanders : an agricultural region becoming increasingly specialized. Hommes et Terres de Nord, 2:41-59.

Gillmor D. A., (1967). The agricultural regions of Ireland. lrish Geography 5 (4) : 245-261.

239

Grosso R., (1976). Cultivation in the Comtat region. Meditterranée, 24:51-58.

Guermond Y. & MassiasJ.-P., (1974). Changes in agriculturalland-use in Normandy. Geographia Polonica (Warsaw) 29 :193-204.

Kampp A. H., (1959). Some types of farming in Denmark. Oriental Geographer , East Pakistan. Cited in Kampp (1970).

Kampp A. H., (1970). The changing patterns of land-u se and the agro-geographical division of Denmark. Geographia Polonica (Warsaw), 19, 171-184.

Kostrowicki J., (1976). International Geographical Union. Commission on Agricultural Typology. World Types of Agriculture, Warsaw, 49 p.

LeeJ., (1970). Unpublished data, J ohnstown Castle, Wexford, Ireland.

Netherlands Central Bureau of Statistics, (1980). UNESCO-Meeting on Land-Use Statistics. Mimeograph paper, Geneva, 5 p.

NN, (1977). A framework for Land Evaluation. International Institute for Land Reclamation and Improvement,Wageningen, Publ. No 22, 87 p.

Tambuyzer C., (1971). Regional analyses of Belgian agriculture, parts V and VI. Cahiers de l'Institut Economique Agricole, Ministère de l'Agriculture, Bruxelles, No. 136/RR/114 and No. 130/RR/110.

Vanzetti C., (1980). Personal communication.

Summary

This review paper discusses the concept of farming systems and land utilization types in the context of land evaluation research. Various information sources are collated wit~ a view to provi~ing an initial insight into farming systems and land utilisation types throughout the E.E.C. The study indicates that th ere is a sizeable data po~l relating to farming typology through~ut the Community. In the fin~l analysis farming systems throughout most of the E.E.C. can be subdivided into four classes: (1) perennial tree or shrub crops, (2) tillage crops (annual), (3) grazing or grassland (pastu.re and ruminants ) and (4) grazing and tillage alternating.

The large st soil map available for the entire E.E.C. is of 1: 1 million scale. Two questions are posed (1) what level of refinement of the four classes and (2) what level of information on the attributes of the farming systems are necessary in the context of an E.E.C. land evaluation research program me based on a soil map of 1: 1 million scale.

240

Etat des connaissances et problèmes liés à la défmition et à la délimitation des systèmes culturaux et des types d'utilisation des terres en Europe

Résumé

Cet article de synthèse discute Ie concept du système cultural et du type d'uti­lisation des terres dans Ie contexte des recherches sur la vocation des sols. De nom­breuses sourees d'information ont été consultées afm d'acquérir une idée de base sur les différents systèmes culturaux et types d'utilisation des terres existants dans les pays de la Communauté Européenne. L'étude démontre qu'il existe un grand nombre de travaux sur la typologie culturale dans la Communauté. Finale­ment, les systèmes de la plupart des pays de la CEE peuvent être regroupés en quatre classes: (1) les cultures arbustives pérennes, (2) les cultures arables annuel­les, (3) les paturages et prairies, et (4) l'alternation des cultures arables et des patûrages.

La carte des sols la plus grande pour l'ensemble des pays de la Communauté Européenne est à l'échelle 1/1.000.000. Deux questions se posent à ce propos: ( 1) quel degré de détail pour les quatre classes et (2) quel niveau d 'information pour les facteurs influençant les systèmes culturaux sont nécessaires dans Ie con­texte d'un programme de recherche sur la vocation des terres dans Ie CEE, basé sur la carte des sols à l'échelle 1/1.000.000.

Kennis en problematiek met betrekking tot de defmitie en de afbakening van kul­tuursystemen en bodemgebruikstypes in Europa.

Samenvatting

Dit overzichtsartikel behandelt de concepten "kultuursysteem" en "bodemge­bruikstype" in de context van het landevaluatieonderzoek. Verschillende informa­tiebronnen werden geraadpleegd teneinde een overzicht te krijgen van de bestaan­de kultuursystemen en bodemgebruikstypes in de landen van de Europese Ge'­meensehap. De studie toont aan dat er veel gegevens bestaan omtrent de landbouw­typologie in de Gemeenschap. Tenslotte kunnen de kultuursystemen van de diver­se landen in vier groepen onderverdeeld worden : (1) meerjarige boom- en struik­gewassen, (2) eenjarige landbouwgewassen, (3) grasland en veeteelt, en (4) afwisse­ling van veeteelt en eenjarige gewassen.

De grootste bodemkaart voorhanden voor de gehele Europese Gemeenschap is op schaal 1/1.000.000. Twee vragen dringen zich hierbij op : (1) wat is de graad van detail voor de vier klassen, en (2) welk niveau van informatie over de kultuur­systemen is noodzakelijk om met goed gevolg een onderzoeksprogramma over landevaluatie uit te voeren gebaseerd op deze 1/1.000.000 bodemkaart.

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PEDOLOGIE, XXXI 1 2, p. 243-266, 11 tab. Ghent,1981.

THE SUITABILITY OF SOILS FOR BUSH BEANS (PHASEOLUS VULGARIS L.)

1.INTRODUCTION

J. VANDAMME K. VANNERUM

A. de la KETHULLE D. LAMBERTS

Studiecentrum voor Tuinbouwgronden, (Leuven), Study centre for horticultural soils (Louvain) directed by Prof. Dr. Ir. L Scheys, and subsidized by LW.O.N.L., LR.SJ.A., Brussels. (Institute for encour­aging Scientific Research in Industry and Agriculture) .

The "Studiecentrum voor Tuinbouwgronden" (Study Centre for Horticultural soils) of the Catholic University of Louvain is charged with the study of the suitability of the Belgian soils for different econ­onomically important crops, and peculiarly for vegetables.

Same of this research has already been finalized and the results have been published for strawberries (Van Nerum et al , 1966), for asparagus (Van Nerum & Palasthy, 1968), for white endive (witloof) (Van Nerum, 1976) and for tomatoes (Vandamme, 1978, Vandamme & Lamberts, 1978).

This paper deals with the suitability research of soils for bush beans (Phaseolus vulgaris L.) grown for canning. At the same time a complementary study has been undertaken concerning the optimum fertility conditions on the different soil classes (Vandamme et al., 1979 b), the results of which will also be published in another paper.

The cultivation of bush beans is important for the Belgian horti-

J. Vandamme, Dr. Ir., & A. de la Kethulle, Ir. - Research workers at the Study Centre for horticultural Soils. K. Van Nerum, Dr. Ir. & D. Lamberts, Dr. Ir. - Research workers at the Faculty of Agronomy of the Catholic University of Louvain, Kardinaal Mercierlaan 92, 3030 Heverlee, Belgium.

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culture. In 1978, it represents an income of 306 million Belgian Francs, which is about 3.3 % of the total income of the vegetable culture in the open field. With regard to the surface however, it occupies almost 9 % óf the area grown with vegetables, and is spread over several natural regions "in Lower and Middle Belgium. Further it comprises about 14 % of the vegetable production for canning. (I.E.A., 1979).

2. GENERAL DATA CONCERNING THE RESEARCH

2.1. Situation of the survey

Af ter a preliminary study in order to get acquainted with the problems concerned and with the cultivation techniques, we proceed­ed in 1968 to a field survey, which was continued in 1970, and from 1972 til11974~ This study was carried out in collaboration with seven canning-factories, the fields of which were spread over West-Flanders, the Antwerp Campine, N. E. Limburg, the loamy region of Brabant and of the Hesbaye as well as over the polders of the southern part of zeeland (Zeeuws-Vlaanderen) in the Netherlands.

2.2. Methods of investigation

The required information is obtained directly from fields, which are cultivated as usual without any interference.

For the concerned fields, a detailed pedological prospection is carried out and the most important data with regard to cultivars, manuring, liming, cr op rotation, etc., are noted. At the time of the optimum ripeness of the beans, i.e. the same day or one or two days before the mechanical harvest, a sample of about 4,5 m2 area (2 rows of 5 m) taken, pods are gathered and the yield (total weight of the pods) is determined. The number of plants is noted, the distance between the rows is measured and the crop conditions evaluated. Besides this large sample, a small sample of 25 plants is taken, which is brought to the laboratDry for various measurernents .and also for a chemical analysis of the beans and the pods.

In the years 1968, 1970 and 1972 the total production of the large sample was brought to I.N.A.C.O.L. (*) at Wezembeek-Oppem, where a precise evaluation of the size and many useful measurements and tests were carried out. The results of this investigations will be treated in another paper.

(*) I.N.A.C.O.L. : Institut National pour l'Amélioration et la Conservation des Légumes.

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2.3. Phytotechnical conditions

At first a distinction is to be made between leasing and contract cultivation. In the former case the canning-factory hires the land and provides the culture whereas the farmer receives an agreed hire-price. In the latter case the farmer is responsible himself for the culture and and sells his product to the canning-factory.

In the loamy region and in the polders the bush beans are cultivated as the only erop of the season. On the lighter soils, the beans are cul­tivated mostly as a second erop, af ter peas, spinach or carrots, but are considered as the main erop.

The sowing-data vary from mid-May till end-J uly and the harvesting is done between the beginning of August and the end of September. Late crops, which afford notably lower yields because of bad climatic conditions, are not harvested or the results are dropped afterwards. The beans are sown on rows with a distance of 42 tot 45 cm and at a quantity of 90 to 100 kg per ha.

Manuring differs widely and varies around the following averages : N : 135; P : 125; K : 175 kg/ha. The most frequently applied herbicid is Aresin-Kombi, working on the basis of DNBP and monolinuron. In most cases sprays are carried out against plantlice, bean fly and also against botrytis.

In 1968 and 1970, a great part of the harvest was still carried out manually but from 1972 on mechanical harvest is in common use.

2.4. Parameters of the productivity

The yield, or total weight of the pods, is a first parameter for the determination of the productivity, but this is not the only criterium.

Coarse pods give a higher yield but a lower quality, and for this . reason the canning-factories prefer pods of a medium size. From this viewpoint the size of the pods and the distribution of the yield over the different size classes is very important. A reliable parameter for the sizing and distribution is the average weight per pod or pod-weight.

Also the number of pods per unit- area or pod-density, may be considered as a very useful productivity parameter. The pod-density indeed is a criterium for the generative growth or fructification of the bush beans.

As the pod-'Weight increases with the ripeness this can give an in­accurate idea about the productivity (de la Kethulle, 1980). There­fore, sampling is only made about the moment of the optimum ripe­ness. In a few cases of marked overripeness, a correction has to be made.

245

Otherwise, the percentage of undeveloped pods, which are still too small to be harvested, can be relatively high, due not only to a pre­mature harve~t but also to the type of soil and to the cultivar. In this way, the percen~age of too small pods is a complementary criterium for the size distribution and quality.Another complementary criterium for the quality is the percentage of rotten pods, affected by botrytis.

These parameters are deduced from two different samples. The yield or weight-production is obtained by weighing the total amount of pods, gathered from the large sample on the field. The average pod­weight on the contrary is computed from the small sample in the laboratory . The pod-density is required by a combination of data from the two samples, i.e. the number of plants per unit-area is counted on the field with the collection of the large sample, while the number of pods per plant is noted from the small sample in the laboratory.

Theoretically, the number of pods multiplied by the pod-weight must be equal to the production. Since however data fr om different samples are compared, it is possible to come to erroneous results. With respect to our survey the data for the calculated production do only slightly differ from the real production; hence, the relation between both variables is highly significant. The correlation coefficient is 0,802 for 493* degrees of freedom, which is an indication that both samples are representative and comparabie (1).

In a few cases, where the data of the calculated production differ too widely from the real production, a correction has been applied.

3. FACTORS OF THE PRODUCTION

3.1. Climatic conditions

Bush beans, just like other crops in the open field, are very suscept­ible to the influence of the climatic conditions. Thát is the principal reason why the survey has been repeated during five years.

The main meteorological data for the growing-period of the five years are discussed more in detail in chapter 4.1. These data refer to the station of Ukkel (Brussels) but are valid for the prospected regions, as an approximationof the influence of the climatic conditions on the crop and as a comparison from one year to another.

(1) The correlation has been computed only for the data of the years 1972, 1973 and 1974.

246

3.2. Cultivars

The culture of bush beans is characterized by a large variation in cultivars.

During the five years of research 28 different cultivars have been sampled. Some of them which we re only grown in the first years and since we re abandoned, have been omitted for the computation. This explains the limited number of plots for the years 1968 and 1970. On the other hand some cultivars, which were selected by the same seed­house and which differed only slightly in productivity could be taken together as one group for comparison with other cultivars.

In this way, the number of cultivars or groups of cultivars, the results of which are taken into account for the computation of the productivity, is brought down to 14.

The distribution of the plots over the different cultivars is quite unequal. Some cultivars have been grown only on a limited number of soil classes, of ten connected with the region and the canning-factory. Superba and Goldjewel have yellowish pods and have been studied only in 1972, which explains their low number of plots. Two cultivars have been sampled only twice, with the purpose to compare them with the other more common cultivars.

3.3. Soils

The classification of the soil is based on the estimation of the texture, the drainage class and the prof tie development, according to the criteria established by the Soil Cartographic Centre of Belgium (Tavernier & Maréchal, 1958).

The investigated plots are spread over a wide sc ale of soil textures, going fr om heavy clay (symbol U), to sand (symbol Z), connected with the landscape-pattern. In this way a first distinction is made according to the nature of the soil material : alluvial versus eolian soils. Moreover , for each textural class of the eolian soils, a distinction is made between the dry and the humid soils.

The classes of the dry soils embrace the moderately dry (class c) as well as the dry (class b) soils with a sand y loam (L) to sand y (Z) texture. The dry soils with a loamy (A) texture are all well drained (class b) and have a permanent deep groundwater-table. The humid soils belong to drainage class d. Wet soils, belonging to the drainage classes e or h, are too wet and are rarely used for the culture of bush beans.

In all but the dry loamy soils, there is a fluctuation of the water­level. This fluctuation is moderate in the polder soils, but reaches a

247

meter or more in the eolian soUs, presenting the following average season-Ievels (Vandamme & De Leenheer, 1969). water level in winter dry soUs: 50-120 cm humid soUs: 20-50 cm

in summer + 150 cm 120-150 cm.

With regard to the profUe development a distinction has been made only for the dry loamy soils. Connected with the undulating relief, there is a continuous sequence of slightly eroded soUs on the plateaus and the slopes, with a shallow textural B-horizon (series Aba) and of light colluvial soUs in the depressions (series Abp).

As to the humid loamy soUs and to the soUs on sandy loam only the most common series, characterized by a more or less degraded textural B horizon (symbol a or c), have been sampled.

In the sandy soils, with textures ranging from light sandy loam to sand (classes P, S and Z) no distinction is made for the profUe develop­ment as this is implicitely related to the difference in textural class. (Scheys, 1955). The argÜlic horizon appears in bands, showing more or less discrete nodules and grading, from a Glossudalf to a Ferrudalf, and even to a Spodosol. Commonly however, these light soils are deeply ploughed and highly enriched in organic matter. The original diagnostic features are destroyed and faded away or even have dis­appeared.

The alluvial polder soUs are all characterized as humid soUs (class d) without discernible profile development (symbol p). As to the textural class, they have been divided into heavy or light clay soUs, according to their clay content, whichever is higher or lower than 35 %.

By disconsidering the profile development and grouping the dry and moderately dry soUs, the number of soU classes to be examined has been reduced to 13, so th at for every soil class a sufficient number of plots was sampled to obtain statistically reliable results'.

4. COMPUTATION OF THE PRODUCTIVITY

The computation of the productivity of the different soU classes is based on the data of the individual plots. These result however from a heterogeneous population, with an interference not only of the suitability of the soils, but also of the productivity of the cultivars and of the influence of the climatic conditions. In this situation, we have to compute the significances of the variabUity due to the 3 sources of variation, i.e. the year as related to its climatic conditions, the cultivar and the soil class, and to their interactions.

Since we .can start from an a priori classification, the most adequate

248

Table 1

Results of the variance analysis,. computed for the yield, the pod-density (number of pods per are) and the pod-weight

Sources of variance Degrees Yield Pod-density Pod-weight of

Mean F-value F-value F-value freedom Mean Mean square square square

Years 4' 36,383 31.28** 43.513 10:21** 138,830 61.27**

SoU classes 12 7,987 6.87** 55.123 12.93** 21,940 9.68**

Cultivars 13 5,730 4.93** 88.786 20.83** '20,310 ~.96* *

Interaction : Year x soU class 37 2,710 2.33** 12,424 ' 2.91** 6,382 2.82** Year x cultivar 21 1,962 1.69** 21,682 5.09** 21,439 9.46** SoU x cultivar 67 524 ' 0.45 13,943 3.27** 8,435 3.72**

Year x soU x cultivar 21 2,182 1.88 4,594 1.08 3,567 1.57

Individuals within subclasses 405 1,163 4,263 2,266

For degrees of freedom 4 and 405: F 0.01 = 3.36; for degrees of freedom 21 and 405: F 0.01 = 1.90 " " " " 13and405:FO.01=2.17; ·" " " " 37and405:FO.01 = 1.67

" " " 12 and 405: F 0.01 = 2.23;" " " " 67 and 405: F 0.01 = 1.50.

methad for the statistical computation of the results is the variance analysis.

The results of these variance analyses for the three principal para­meters are presented in table 1. For the sake ofbrevity, they are collected in one table and the data for the sum of squares are dropped. These however may be found very easily, merely by multiplying the mean square with the number of degrees of freedom.

The influence of the year and the annual climate, as well as of the cultivar and of the soil is very significant. The influence of the annual climate is even more significant for the yield and for the pod-weight than th at of the soil and of the cultivar. On the contrary, the cultivar is the most important source of variation for the pod-density. The different interactions of the first order are also significant, but the F -value is much lower than for the primary sources of variance.

At any rate, since the interferences of the annual climate and of the cultivar are notabie and even more significant than th at of the soil, they must be taken into account and checked systematically, in order to obtain finally the intrinsic productivity of the soils, independent of the extra-pedological factors.

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4.1. Influence of the climate

As a first step, the influence of the year is computed, i.e. the variance in productivity due exclusively to the difference in climatic conditions and irrespective of the soil and the cultivar.

Since however the distribution of the plots over the cultivars and soil classes is disproportioned and is unequal from year to year, the year-factor is calculated on the following way.

F or each subclass (soil class x cultivar) the ratio between the annual productions is calculated (in comparison with the production of

1973) and provided of a weight according to the formulakk1kk2 - where 1+ 2

in k1 and k2 are the respective numhers of plots for the compared

years. From the sum of the weighted ratios their mean can he deduced. This ratio is the year factor and illustrates the relative influence of the climatic conditions of the concerned year on the production, irrespective of soil and cultivar.

This ratio is more precise and reliahle than the ratio hetween the average productions of two compared years. In fact, the real average yield in 1968 was 12,307 kg per ha whereas that of 1973 amounted to 13,549 kg per ha, which means an increase of 9 %. In 1973 however more productive cultivars were grown on a much larger scale than in 1968. By neutralizing these influences i.e. hy comparing the yields on the same soil class and for the same cultivar, the difference between both years was reduced to 2 %, as can be found in table 2. In this tahle the productivity level is calculated for each of the five compared years, as an exclusive function of the influence of the climate.

Notwithstanding marked differences in climatic conditions (tabie 3) between the years 1968, 1972 and 1973, there was little difference in productivity. In 1968 the yield was lower as a direct result of the humid summer following a cool and dry month of May. In 1972 the cool wet spring induced a deficient germination and early growth, whichever was amended in summer by a higher number of pods per plant. Finally, the pod-density was higher than in 1968 but the pod­weight was slightly lower. The growing season 1973 was more sun­ny, warmer and drier than 1968 and 1972, but due to a very hot anel dry period in J uly and August the growth was disturbed and the yield was not higher than in 1972.

The high increase in production in 1970 was due to a sunny warm growing-season with a relatively scarce but well distributed rainfall; the pod-density as well as the pod-weight were higher.

The growing-season of 1974 was moderately warm, moderately

250

Table 2

Influence of the climate : average yield, pod-density (number of pods) and pod­weight per year, af ter elimination of the influence of soil and cultivar

Year Number Yi~ld Number of pods - . Pod-weight of

kg/ha Relative plots Per are Relative In gram Relative

1968 51 12,891 98 38,432 93 3.36 106 1970 36 17,066 130 46,372 112 3.69 116 1972 99 13,221 100 41,528 100 3.18 100 1973 246 13,168 100 41,404 100 3.18 100 1974 149 16,828 128 42,232 102 3.98 125

Total 581 14,328 41,683 3.44

Table 3

The climatic conditions during the years of the surveYidata for ukkel (Brussels)

May June July August .Septem- . Growing ber season :

May-. August

Sunshine, in hours 1968 151 160 175 122 122 608 1970 183 265 172 197 178 817 1972 147 139 168 172 167 626 1973 173 250 173 224 168 820 1974 200 197 150 212 124 759

Normal 221 197 200 199 161 817

Average temperature, in Co 1968 11.3 15.5 16.4 16.8 14.6 15.0 1970 13.5 18.3 16.4 17.4 15.4 16.4 1972 11.9 14.1 17.6 16.1 12.2 14.9 1973 12.9 17.2 17.5 19.2 15.4 16.7 1974 12.2 15.4 15.8 17.2 13.0 15.2

Normal 12.8 14.9 16.8 16.4 14.0 15.2

Rainfall, in mm 1968 48 45 108 94 92 295 1970 33 25 69 70 70 197 1972 98 76 85 56 47 276 1973 79 44 63 28 78 245 1974 55 88 73 79 143 295

Normal 63 65 90 75 66 293

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sunny and humid. There was a sufficient water supply and the pods could develop much better than in the former years. The average pod­weight increased with 25 %, which finally caused an increase in yield of 28 % in comparison with 1973.

4.2. Productivity of the cultivars

Once the year-factor known and controiled, the production per subdass (soil class x cultivar) can be calculated and the weighted mean production per cultivar deduced. Since the Prelubel cultivar group has the highest frequency and the large st distribution, it is considered as a reference level for comparison with the other cultivars. Table 4 gives the absolute and relative results for the three parameters, ex­clusively due to the productivity and vitality of the different cultivars. The results show' marked differences, which may be highly significant, as was found in table 1.

Colana, Centrum and Record as weil as Dubresco cultivars afford higher yields, only due to a higher pod-weight, since the pod-density is lower than for Prelubel. Felix and Iprin on the other hand have finer pods but the production is higher because of a. marked increase in the pod-density. Corene, Y olande, Cordon and Rofin are less pro­ductive than Prelubel; the average pod-weight may be higher but the pod-density is considerably lower. Finally, the cultivars Impala and nr. 551 are characterized by a very high number of pods and con­sequently by a high production. These results however are not reliable as they are only based on two observations.

The same remark concerns the results of Iprin, Superba and Gold­jewel and even of Rofin. The yellowish cultivars Superba and Gold­jewel show indeed a notabie decrease in pod-density which implies a decrease in yield.

In general, these data confirm the results obtained by Vulsteke and Bockstaele (1967-1977) with their experiments on cultivars during several years, peculiarly with the results of the years 1972, 1973 and 1974. In comparison with Prelubel, they also acquired higher yields for Felix and Rofin, but lower for Corene, Iprin and y olande. The number of pods per plant, comparable with the pod-density, is higher for Iprin, Rofin and Felix than for Prelubel. It is almost equal for Corene, and considerably lower for Yolande. Iprin and Felix produce flner pods; these of Rofin and Corene are comparable with those of Prelubel, while Y olande is characterized by coarser pods.

All these results obtained by Vulsteke and Bockstaele (1967-1977) correspond fairly weil with the data of our experiences.

252

Table 4

Comparison of the cultivars: average yield, pod-density and pod-weight per cultivar af ter elimination of the: influence of year and soil

Cultivars Number Yield Number of pods Pod-weight of plots kg/ha Relative Per are Relative In gram Relative

Prelude Prelubel 179 14,328 100 43,935 100 3.26 100 Preva Preresco·

Co ram 85 12,609 88 37,345 85 3.45 106

Co re ne

Colana 61 14,887 104 40,860 93 3.58 110

Centrum 56 14,743 103 42,178 96 3.42 105

Record

Cordon 51 13,726 96 36,466 83 3.81 117

Felix 43 16,062 112 51,404 117 3.03 93

Yolande 40 13,311 93 36,993 84 3.52 108

Dubresco 36 16,334 114 43,496 99 3.94 121

Rofin 12 13,024 91 39,541 90 3.32 102

Iprin 5 14,600 102 47,450 108 1.86 88

Impala 2 17,194 120 53,162 121 3.26 100

nr. 551 2 18,254 127 49,647 113 3.65 112

Superba 6 12,881 90 39,103 89 3.32 102

Goldjewel 3 10,345 - 72 36,027 82 3.16 97

Total 581 14,328 41,683 3.44

3.3. Productivity of the soils

Knowing the intrinsic influence of the cultivar, as weil as of the annual climate, it is now possible to calculate the productivity, merely as a function of the soil unit.

By applying a correction per year and cultivar for each of the 581 plots, the average yields per soil unit can be computed. Af ter the correction of these 581 data new variance analyses were applicated, and as such the statistic probability of the obtained differences was known af ter elimination of the influence of the year and of the cultivar. By application of the test of Tukey (in Snedecor & Cochran, 1967) the least significant difference for P= 0.05 could be determined.

The results of these computations are presented in tables 5, 6 and 7,

253

Table 5

Average yie1ds in kg/ha per soil dass, re1ative yields as compared to those on dry sand and significant differences

SoiLdass Soil Number Yi~ld Significant series of plots In kg/ha Relative differences

;;.. 1670 kg

Loam dry : plateau Aba 146 15,254 123 ba

depression Abp 71 16,963 136 a humid : plateau Ada, Adc 21 13,193 106 bbb

Sandy loam dry Lba,Lbc 18 13,749 110 b a

Lca, Lee humid Lda, Ldc 28 13,409 108 bb

Light sandy loam dry : Pb (*) 32 13,390 108 bb

Pc (*) humid Pd (*) 41 15,032 121 b a

Loamy sand dry Sb (*) 60 12,824 103 bbb

Sc (*) humid Sd (*) 59 14,108 113 b a

Sand dry Zb (*) 42 12,446 100 bbb

Ze (*) humid zd (*) 26 13,214 106 bbb

Polder soils heavy day Udp 17 12,070 97 bbbb light day Edp 20 13,752 110 b a

Total 581 14,328 F-value : 9.12

For degrees of freedom 12 and 568 : F 0.01 = 2.22

(*) For the lighter soils, no profIle development is indicated.

respectively Eor the yield, the pod-density and the pod-weight. Besides the absolute results, the relative data are given, expressed as a percent of the results obtained on the dry sandy soils. In the last column the significance of the differences is indicated, i.e. all the differences -equal or - greater than the least significant difference are ~ndicated with "a" versus "b~'. At the bottom of this column the F-vaiue is communicated. This is highly significant for each of the three para­meters.

In table 8 the results of the three parameters are presented in a way

254

---------------------------------------------

Table 6

Average pod-density (number of pods per are) per soil unit and significant differ­enees between soil units

Soil unit Soil Number Number of pods Significant series of plots

relative differenees

per are ~ 4960

Loam dry : plateau Aba 146 43,612 116 aa

depression Abp 71 45,734 122 a a humid : plateau Ada, Ade 21 39,838 106 b a

Sandy loam dry Lba,Lbe 18 44,261 118 a a

Lea, Lee humid Lda,Lde 28 39,389 105 b a

Light sandy loam dry Pb (*) 32 42,038 112 a

Pc (*) humid Pd (*) 41 42,288 113 a

Loamy sand dry Sb (*) 60 41,455 110 a

Sc (*) humid Sd (*) 59 40,463 108 b a

Sand dry Zb (*) 42 37,564 100 bbb

Ze (*) humid Zd (*) 26 37,512 100 bbb

Polder soils heavy day Udp 17 34,335 91 bbbb light day Edp 20 38,905 104 bb

Total 581 41,683 F-value : 3.87

For degrees of freedom 12 and 568 : F 0.01 = 2.22

(*) For the lighter soils, no prome development is indieated.

as to observe better the influence of texture and drainage as weil as of their interactions. The dry loamy soils of the plateaus and of the depressions are taken together to permit a better comparison with the other soil classes. These loamy soils are by far the most productive for bush beans; pod-density as weU as pod-weight is high. On dry soils the yield decreases systematically from loam to sand.

The pod-density decreases less obviously but the pods are smaller. On the fine textured humid soils, the pod-density is considerably

lower but the pod-weight is higher. This phenomenon raises some

255

Table 7

Average pod-weight per soil class and signifieant differenees between soil classes

Soil class Soil Number Pod-weight Significant series of plots In gram Relative differenee

~ 0.36 g

Loam dry : plateau Aba 146 3.51 107 a

depression Abp 71 3.72 113 a humid : plateau Ada, Ade 21 3.50 106 a

Sandy loam dry Lba,Lbe 18 3.16 96 bb

Lea, Lee humid Lda, Lee 28 3.50 106 a

Light sandy loam dry Pb (*) 32 3.13 95 bbb

Pe (*) humid Pd (*) 41 3.53 107 a

Loamy sand dry Sb (*) 60 3.07 93 bbbb

Se (*) humid Sd (*) 59 3.49 106 a

Sand dry zb (*) 42 3.29 100 b

Ze (*) humid Zd (*) 26 3.43 104 a

Polder soils heavy clay Udp 17 3.53 107 a light clay Edp 20 3.52 107 a

Total 581 3.44 F-value : 4.15

For degrees of freedom 12 and 568 : F 0.01 = 2.22

(*) For the light er soils, no profile development is.indicated.

questions which ask for a further examination and analysis of the parameters of the productivity. Is the lower pod-density on the heavy humid soils affected by a too scarce number of plants or by a too scanty number of pods per plant? What is the relation between the pod-density and the pod-weight ? In what way is the average pod­weight affected by the percentage of undeveloped pods ?

3.4. Comparison of the productivity parameters and their components

The influence and interrelationship of the components of the pro-

256

lil ~ 0 lil

>-1-0

0

lil ~ 0 lil

'"0 ·s ;::s

::r:

Table 8

Average yield (kg/ha), pod-density and pod-weight (in gram) per soil dass; eomparison of the three parameters and influenee of soil texture and drainage

; dass

Eolian soils Polder soils

Loam Sandy Light Loamy Sand Heavy Light loam

sandy sand day day loam

Soil series Aba, Abp Lba,Lbe pb (*) Sb (*) Zb (*) Lea, Lee Pc (*) Sc (*) Ze (*)

Number of plots 217 18 32 60 42

Yield kg/ha 15,813 13,749 13,390 12,824 12,446 Relative 127 110 108 103 100

Number of pods per are 44,300 44,261 42,038 41,455 37,564 Relative 118 118 112 110 100

Pod weight in gram 3.58 3.16 3.13 3.07 3.29 Relative 109 96 95 93 100

Soir serie·s Ada, Ade Lda, Lde Pd (*) Sd (*) Zd (*) Udp Edp

Number of plots 21 28 41 59 26 17 20

Yield kg/ha 13,193 13,409 15,032 14,108 13,214 12,070 13,752 Relative 105 108 121 113 106 97 110

Number of pods per are 39,838 39,399 42,288 40,463 37,512 34,335 38,905 Relative 106 105 113 108 100 91 104

Pod weight in gram 3.50 3.50 3.53 3.49 3.43 3.53 3.52 Relative 106 106 107 106 104 107 107

(*) See table 5

ductivity have been examined for the years 1972, 1973 and 1974 and the results are presented in tables 9 and 10.

Table 9 gives the averages per soil unit for different parameters of the productivity. The data for yield, pod-density and pod-weight are not the same as those which occur in tables 5 to 8, not only because of a decreased number of plots, but also because of the absence of any year or cultivar correction. Indeed, it is in the first instance the intention to compare the different parameters for examining the mutual influences.

As a complement to the results of table 9, the correlations between the different productivity factors and parameters have been computed for the same data of the three years (tabie 10). The results of both tables elucidate the input of the factors and parameters on the pro-

257

Table 9

Comparison of the produetivity parameters and their eomponents, per soil class, for the years 1972, 1973 and 1974

Soil class Soil series Number Yield Number Number of pods Pod- % of plots kg/ha of plants per per are weight undeve-

per are plant (gram) loped pods

Loam dry : plateau Aba 120 15,487 2,637 17.1 45,013 3.41 20.3

depression Abp 61 17,107 2,622 18.1 47,380 3.74 17.0 humid : plateau Ada, Ade 10 13,800 2,638 13.9 36,713 3.80 16.0

'sandy loam dry Lba,Lbe 18 13,194 2,519 18.0 45,405 3.03 21.3

Lea, Lee humid Lda, Lde 28 13,811 2,449 17.2 42,168 3.28 22.2

Light sandy loam dry P.b(*), Pe(*) 28 12,793 2,556 15.9 40,639 2.90 23.0 humid Pd (*) 19 14,358 2,445 17.5 42,879 3.28 18.7

Loamy sand dry Sb(*), Se(*) 53 13,090 1,943 22.0 42,655 3.13 20.0 humid Sd (*) 53 14,460 2,117 19.0 40,306 3.63 16.8

Sand dry Zb(*), Ze(*) 42 12,336 2,014 18.4 37,040 3.28 18..4 humid zd (*) 25 13,244 2,328 16.2 37,800 3.43 16.9

Polder soils Heavy clay Udp 17 12,235 2,944 12.2 35,792 3.40 14.8 Light day Edp 20 13,295 2,925 13.1 38,460 3.36 16.3

Total 494 14,329 2,432 17.4 42,206 3.39 18.9

(*) For the light soils, profue development is not indieated.

ductivity, and explain the interrelationship between them. The plant-density, or number of plants per are, differs clearly and

systematical~y as a function of the textural class and the correlation is highly significant.

In contrast to what could be expected the greatest plant density is found on the polder clay soils. On the other hand the lowest number of plants is found on the sandy soils (textural classes S and Z), especial-lyon the dry ones.

The seed application may be higher on the polder soils, but th ere is no indication that th is is lower on the sandy soils; indeed, the examined sandy soils are spread over th ree different regions and sow-ing was done for four different canning-factories.

258

% rotten pods

2.31 2.74 7.94

2.15

1.93

2.09 1.36

2.65 1.40

1.52 I 1.66

1.43 1.81.

2.19

Table 10

Correlations between the productivity parameters, the main soil components and the cultivar, for the years 1972,1973 and 1974 (494 plots)

Yield Number Number Number Pod- % pods % rotten per are of - of pods of pods weight deve10ped pods

plants per plant per are per are

Number of plants per are 0.203 Number of pods per plant 0.215 -0.549 Number of pods per are 0.488 0.293 0.591 Pod-weight 0.493 ns -0.204 -0.243 % undeveloped pods -0.334 ns 0.244 0.213 % rotten pods 0.191 0.143 ns ns Texture class 0.199 0.453 -0.296 + Drainage class -0.189 ns -0.124 -0.230 Prof tie development - 0.174 ns -0.148 -0.106 Cultivar 0.238 + 0.191 0.297

P 0.01 : r = 0.116; p.0.05 r = 0.089 + or - mean positive or negative correlation for p 0.05 ns : not significant, r less than 0.089.

-0.619 0.216 -0.215

ns ns ns -0.121 ns ns ns +

The spray with the herbicid Aresin-Kombi can influence the germina­tion differently according to the soil texture and the humus content, but these factors are taken into account for the determination of the concentration.

The number of pods per plant, or fructification, is not related to the soil class but there is a highly significant negative relationship with the plant-density.

On the polder soUs the fructification is considerably lower, and this is not only the result of a very high plant-density. On these calcareous soils indeed the uptake of phosphorus is disturbed and the flowering and fructification of bush beans is strongly influenced by the avail­able phosphorus in the soil. (Vandamme et al., 1979, b).

The pod-weight is systematically higher in the humid soils, even when also the pod-density is higher, as is stated on the lighter soils. A sufficient moisture supply during the growing period is a very import­ant factor for the development of the pods.

On the sandy-Ioam soils and still more on light sandy loams, the pod-weight is obviously lower and the percentage of undeveloped pods is higher; this implies that the beans on those soUs have been harvest­ed somewhat prematurely, may be on purpose to obtain finer pods. Also, the commonly used cultivars in those soils are characterized by

259

+ ns -

0.116

finer pods. Most of those soils are situated in West-Flanders and are cultivated for one canning-factory.

The percentage of rotten beans is relatively high on humid loanly soils. The microclimate and the less favourable soU structure may play a certain role, but also the cultivar is important. Vet the climatic con­ditions of the year may promo te or control the extension of a disease in a high degree, for in 1972 for example there were much more rotten pods than in the other years.

From table 10 it can be learned that the yield is correlated with both the pod-densityand the pod-weight. The pod-density is deter­mined much more by the number of pods per plant than by the number of plants, even if there is a highly significant negative correlation between both. The pod-weight is negatively related to the fructification and to the pod-density ; the negative correlation with the percentage of undeveloped pods is obvious.

The plant-density is highly correlated with the textural class, even more than the yield.

As for the drainage class only negative correlations have been stated. These results however are biased by the very high number of plots on dry loamy soils. The correlations with the profUe development too are rather negative, which indicates that number of pods and the yield decrease on more differenciated profiles, like Glossudalfs, Ferrudalfs and Spodosols.

The correlations with the cultivar emphasize its influence with regard to the pod-density and to the yield.

Finally, the data of tab Ie 10 are in agreement with the results dis­cussed above.

5. DISCUSSION

The results of this study confirm the important and significant in­fluence of the soU on the production.

The dry loamy soils are the most productive. There is a high pod­density and the pods are fairly weU developed which explains the high yields. Even on these soils there is a great difference in favour of the depression soils, where the pod-density as weU as the pod-weight are higher than on the plateaus and slopes. Also De Leenheer & Appel­mans (1977) obtained higher yields for wheat and barley on the depression soils, whereas the results for sugar beets were just opposite. The soils in the depressions are slightly lighter but better protected and they contain somewhat more P, Ca and Mg (Vandamme et al., 1979 b).

260

The dry soUs show a distinct and systematic yield decrease fr om loam to sand as a function of the soU texture. The number of plants decreases considerably, especially on the sandy soils. Then, although there is a highly significant negative correlation between the number of plants and the number of pods per plant, also the pod-density de­creases on the lighter dry soUs. The pod-weight however decreases obviously. The avaUable moisture content of the sandy soUs is much lower than th at of the loamy soUs (Haans, 1960) and crops with a shallow root-system like bush-beans may suffer of a water deficit. Under these conditions, the fructification is reduced (less pods) and the pods are much smaller and/or undeveloped (lighter pod-weight) (de Vos and Toussaint, 1950).

On the light soUs, with a texture of light sandy loam to sand, there is an interaction between the number of plants and the fructific­ation per plant, so that finally the pod-density on the dry soUs differs only slightly from that on the humid ones. The latter are character­ized by a better water supply; the 'pods could develop unchecked and grow thicker, which finally results in an increased yield.

The lowest yields are obtained on dry sands and on heavy polder­clays. The former have too small pods because of the deficient water supply; the latter show pods, as thick and well developed as on the loamy soils, but the pod-density is extremely low because of the poor fructification.

On light polder-day the pod-density is higher and the yield is again increased. These results are not in agreement with those of earlier experiments in the polders of the Scheldt Floodplain north of Ant­werp, wh ere the highest yields were acquired on the heavier soils, not only for cereals and sugar beets, but also for peas and potatoes (Van­damme & De Leenheer, 1960).

Comparing the productivity of the bush beans with other crops on different soil classes, we found mostly similar results. Van Nerum et al. (1968) obtained a decreasing yield from loam to san~ for strawberries. Also for tomatoes (Vandamme 1978) the influence of the soil texture was very important and the production decreased from sandy loam to sand. .

As for white endive (witlof), Van Nerum (1976) ascertained à dis­tinct interaction between drainage ·class and soil texture, more or less corresponding with the results obtained for bush beans. Similarly, the humid sandy soUs afforded higher yields than the dry ones, where­as on löamy soUs, the humid classes were less suitable than the dry ones.

261

Table 11

Soil suitability for bush beans

Suitability Relative Soils production (%) production Soils series Definition

I 120 Aba, Abp, wen drained loamy soils Very and more Pd (*) humid soils on light sandy loam suitable

11 110-119 Lba,Lbe wen drained soils on sandy loam Moderately Lea, Lee, moderately weil drained soils on sandy loam wen suitable Sd (*) humid soils on loamy sand

Edp soils on light polder day

111 105-109 Ada, Ade, Adp imperfeetly drained loamy soils Lde, Ldp imperfeetly drained soils on sandy loam

Moderately pb (*), Pc (*) (moderately) dry soils on light sandy loam suitable zd (*) humid soils on sand

IV 100-104 Se,Sb (moderately) dry soils on loamy sand Ze, zb (moderately) dry soils on sand

Slightly and slightly suitable lower

V < 100 Unsuitable by extrapolation very dry sandy soils

very wet soils

(*) ProHle development not indicated.

Summarizing the obtained results of tables 5 to 9, it is possible to prepare a soil suitability scheme for bush beans, as was already made for other crops. Such a classification can be set up on the basis of differences in yield. The great number of data and the high significanee of the statistic results permit to make an accurate division with a yield­interval of 5 %.

Dry loamy soils are the most suitable and form, together with the humid soils on light sandy loams, the first class. The productivity level of these soils reaches 120 % and more.

The second class comprises soils with a production level of approx­imately 110 % and can therefore be considered as moderately weU suited for the culture of bush beans.

In the third class are grouped the nloderately suited soils, whereas the soils of the fourth class are only slightly suited. This class com­prises the soils developed on heavy polder clay and on dry sand. . By extrapolation, the very dry soils, together with the very wet ones

may be considered as unsuitable for the culture of bush beans; yet,

262

they are grouped in class V.

ACKNOWLEDGEMENT

The authors are largely indebted to the managers of the different canning-factories for their useful collaboration on the field. Also special mention should go to I.N.A.C.O.L. at Wezenbeek-Oppem (National Institute for amelioriation and better conservation of vege­tables) for calibration and complementary research on pods and beans.

BIBLIOGRAPHY

de la Kethulle A., (1980). De plantvitaliteit als foutbron bij de beoordeling van de rijpheidstoestand van stamslabonen. Mededelingen van het Studiecentrum voor Tuinbouwgronden, 9 : 1-47

De Leenheer L. & Appelmans F., (1977). Influence du type de sol (relief) et des traitements (fumure organique) sur la croissance des céréales. From: Structure et fertilité de sols limoneux sur fermes mécanisées, vol. 11, pp. 355-934. Rijksuniversiteit Gent.

de Vos N. M. & Toussaint C. G., (1959). Over de watervoorziening van stamslabonen. Twintig jaren P.S.C. Wageningen, 1959 : 187-195.

Haansj. C. V. M., (1960). Available moisture in the Netherlands. Versl. Meded. Comm. Hydr. Onderz. T.N.O., 5 : 1-21.

Institut Economique Agricole (1979)~ Statistiques de l'I.E.A.-L.E.1. statistieken. ~inistère de l'Agriculture, Bruxelles.

Institut Météorologique Roya! (I.M.R., K.M.I.). Rapport mensuels - maandelijkse rapporten, ukkel.

Snedecor G. W. & Cochran W. G., (1967). Statistical Methoc1s. Iowa State University Pre ss, Ames, Iowa (6th edition).

Scheys 1., (1955). Bijdrage tot de kennis van de Hagelandse bodems en hun produktiecapaciteit. Doctoraal proefschrift fac. landbouw K.U.Leuven.

Tavernier R. & Maréchal R., (1958). Carte des associations de sols de la Belgique. Pédologie, 8 : 134-182.

Vandamme J., (1978). On the suitability of soils for tomatoes. Pedologie, 28 (3) : 285-305.

Van damme J. & De Leenheer L., (1960). Bodemproduktie op de bijzonderste bodemtypen van de Beneden-Schelde-Polders en invloed van het weder op deze produktie. Meded. Landbouwhogeschool 25 (2) : 869-912.

263

Vandammej. en De Leenheer L., (1969). Variations du niveau de la nappe phréatique au cours de cinq années dans les sols de la Campine anversoise. Pédologie, 19 (3) : 275-320.

Vandamme J. IX Lamberts D., (1978). Bodemgeschiktheid en optimumteelt- en voedingscondities voor tomaten. Agricu ltu ra, 26 (3) : 233-352.

Vandamme J., Van Nerum K., de la Kethulle A., Lamberts D., (1979). Bodemgeschiktheid voor stamslabonen (Phaseolus vulgaris L.) Mededelingen van het Studiecentrum voor Tuinbouwgronden, 6 : 143.

Vandammej., Van Nerum K., de la Kethulle A., Lamberts D., (1979). Optimumteelt- en voedingscondities voor stamslabonen op de verschillende bo­demklassen. Mededelingen van het Studiecentrum voor Tuinbouwgronden, 7 : 1-74.

Van Nerum K., (1976). Wetenschappelijke studie van en voor de witloof teelt. Agricultura, 24 (1) : 125-200.

Van Nerum K., & Palasthy A., (1968). Studie van de bodemgeschiktheid voor de aspergeteelt. Agricu ltu ra, 14 (1) : 1-38.

Van Nerum K., Palasthy A. & Lamberts D., (1966). Studie van de bodemgeschiktheid voor de aardbeienteelt. Agricultura, 14 (4) : 491-530.

Vulsteke G., Bockstaele L., Overzicht van de opzoekingen op stamslabonen in 1967. Stamslabonen. Overzicht van de opzoekingen in 1968. Stamslabonen. Overzicht van het onderzoek in 1972. Stamslabonen. Overzicht van het onderzoek in 1973 en 1974. Stamslabonen. Onderzoek 1976 en 1977. Onderzoek- en voorlichtingscentrum voor Land- en tuinbouw. Beitem-Roese­lare.

Summary

A soil suitability study for bush beans was carried out by area sampling, in cooperation with some canning factories. The fields were cultivated as usual and spread over 13 soil classes, with textures varying from heavy clay to coarse sand. Fourteen different cultivars were sampled.

Yield, number and weight of the pods were chosen as productivity parameters. Climatic conditions were responsible for 30 % variation in yield. Highest pro­

ductions we re obtained on well drained loamy soils; colluvial depression soils (series Abp) gave better results than plateaus or slope soils (series Aba).

Under weil drained conditions, the productivity decreased systematically from loamy to sandy textured soils and this was more due to a decrease in weight of the pods than to their number.

264

On poorly drained soUs, an interaction was found with the texture : light sandy loams (class P) yielded best. On more loamy soUs, under humid conditions, a markedly decreasing number of pods lowered the yield.

The lowest productions were found on dry sandy soUs because of an insufficient water supply, and on heavy polder day soUs because of a very low number of pods.

The results of this study support a suitability soU dassification for bush beans.

L'aptitude des sols pour l'haricot vert

Résumé

En collaboration avec des conserveries, une étude de l'aptitude des sols pour la culture du haricot vert a été effectuée.

Elle est basée sur les résultats d'un échantillonnage pendant cinq années, d'un nombre élévé de champs, englobant 13 différentes classes de sols et 14 cultivars.

Comme paramètres de la production furent choises non seulement Ie poids total de la récolte, mais aussi Ie nombre de gousses par are et leur poids individu el.

Les conditions dimatiques varient d'année en année, et de ce fait elles sont res­ponsables d'écarts de 30 % dans la production totale. L'influence du cultivar est également significative, autant sur Ie nombre que sur Ie poids des gousses. Le type de sol a une influence spécifique sur les paramètres étudiés.

les rendements les plus élevés sont obtenus sur les sols limoneux secs; la pro­duction des sols des dépressions (Abp) dépasse généralement celle des sols de plateaux (Aba).

La récolte diminue systématiquement sur les sols secs, en fonction d'une texture plus grossière, bien plus par Ie poids restreint que par Ie nombre des gousses.

Sur les sols humides, on ob serve une interaction de la classe de texture : les sols sablo-limoneux légers sont les meilleurs; sur les sols plus lourds mal drainés, Ie nombre de gousses par are est insuffisant.

Sur textures sableuses, les sols humides sont plus aptes que les sols secs. Les productions les plus basses se rencontrent sur les argiles poldériennes lourdes (nombre de gousses insuffisant) et sur les sables secs (gousses trop minces ).

Sur la base des résultats de cette étude, une table d'aptitude des sols a été établie.

De bodemgeschiktheid voor stamslabonen (prinsessenbonen)

Samenvatting

In samenwerking met enkele conservenfabrieken werd gedurende vijf ja3;r een onderzoek van de bodemgeschiktheid voor stamslabonen uitgevoerd. Dit onder­zoek is gebaseerd op de bemonstering van praktijkvelden, gespreid over 13 ver­schillende bodemklassen met texturen gaande van zware klei tot zand, en met 14 verschillende cultivars beplant. . .

Als produktivtteitsparameter gold niet alleen de opbrengst, maar ook de peul­densiteit (aantal peulen per are) en het peulgewicht.

265

De produktie kon tot 30 % verschillen van het ene jaar tot het andere. Ook de invloed van de cultivar was, significant, zowel voor wat betreft het peulenaantal als de peuldikte. De bodeminvloed is relevant, zowel voor het peulgewicht als voor de peuldensiteit en de produktie.

De hoogste opbrengsten worden bekomen op droge leemgronden: (series Abp en Aha). Op de droge bodems cl~alde de p'róduktie systematisch van de lemige naar de zandige gronden, meer door een afname van het peulgewicht dan door een vermindering van het aantal peulen.

Op de vochtige gronden is er een interactie met de textuurklassen : de hoogste produkties worden geoogst op licht-zandleem (P-gronden); op zwaardere vochtige gronden is de peuldensiteit veel lager en dus ook de produktie.

Op zandige gronden is de produktie beter op de vochtige dan op de droge va­rianten. De laagste opbrengsten vindt men op zware polderklei (te weinig peulen) en op droog zand (te dunne peulen). De resultaten van dit onderzoek laten toe een bodemgeschiktheidstabel op te stellen.

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PEDOLOGIE, XXXI, 2, p. 267-272, 5 tab. Ghent, 1981.

PR.ODUCTION OF WHITE ASPARAGUS IN CONTAINERS

T.DECKERS D. LAMBERTS

Asparagus (Asparagus officinalis L.) for white spear production is a typical product of areas with a dry sandy soi!. During the last decades the cultivated area in Belgium has decreased from 628 ha in 1959 to 116 in 1979 as aresult 0 f high taxation and labor costs.

In the open field, harvest starts in the middle of April and continues until June 21, allowing the plant from than to build up sufficient reserves for the next year's production. In greenhouses and with soil heating some growers have the possibility to produce during the winter when prices are high but with very high heating costs.

In 1978 the Research Centre for Hydroponics of the University of Leuven (Belgium) started a project (1) on the possibility of producing white asparagus all the year round in dark climatized rooms, similar to the production of Brussels Endives. F or this purpose rhizomes were harvested and placed in appropriate containers in the production room. This year-round production seems to provide high financial returns.

1. PRODUCTION OF THE RHIZOMES

In the classical white asparagus production, one year old seedlings are planted in wide spaced rows (1,6-1,8 m between rows), at a rate of 150 plants per are. After two years of growth, a first limited harvest can be expected and a normal yield is obtained after three years.

For our purpose, planting density in the field can be tripled or even quadruppled. In order to be suitable, plants must be well developed af ter at most two years, and if possible af ter one year. In that case they can produce a sufficient number of spears with commercial size

(1) Research conducted with the financial support of Instituut voor Aanmoedi­ging van het Wetenschappelijk Onderzoek in Nijverheid en Landbouw (IWONL).

T. Deckers & D. Lamberts - Studiecentrum voor Hydrokulturen. Faculty of Agronomy K.U.Leuven, Kardinaal Mercierlaan 92,3030 H'everlee, Belgium.

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and quality. For this purpose cultivars of several European countries were compared. Vegetative propagation of some interesting individual plants looked promising.

Mechanical harvesting of the rhizomes is possible without excessive dammage of the roots. The soil conditions during the field growing period have astrong influence.

Soil texture affects the development of asparagus plants in the open field (tables 1 and 2).

Table 1

Influence of soil-texture on the development of asparagus rhizomes cv. Limbras 18 and 22. (Zl V 2)

Light sandy loam-texture Loamy sand-texture

Sum of cf> mean sp. cf> Sum of cf> mean sp. cf>

Limbras 18 76. 79 9.48 18.80 7.23 Limbras 22 103.49 10.56 26.92 8.69

Table 2

Influence of soil texture on the development of asparagus rhizomes cv. Limbras 18 (Zl V1) by different plant density in the field

Sandy loam-texture Sand-texture

Plant density Sum of cf> mean sp. cf> Sum of cf> mean sp. cf>

300 pl/are 28.91 4.90 20.16 3.60 450 " " 34.20 4.50 19.22 3.10 600 " " 24.96 4.80 22.88 4.40

In the natural condition, loamy soils are better for optimal rhizome development (higher sum of diameters and a better mean spear dia­meter) than the sandy soils. In the classical white asparagus produc­tion sandy soils are necessary for moulding up, but they are not optimal for plant development. In the field loamy soils behave better than other soil types because of their better water retention properties. However, soils with loamy sand and even sand texture give higher yields if they are irrigated (tabie 3).

In an irrigation experiment whereby the soil moisture was maintain­ed at pF 2,4 the rhizomes we re harvested af ter a one year growing period in the field. The actual production period was 4 weeks at a róom temperature of20oC. For -winter production (November-February) it is necessary to store the rhizomes at a temperature of lOC and high

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Table 3

Influenee of trickle-irrigation (PF 2,4) on the asparagus produetion

Soil type tot. prod/pl. number of sp. </> (mm) m. sp. weight spears/pl. (g)

Weildrained sand y loam +irr. 42.7 8.33 5.25 5.07 - irr. 39.4 8.27 5.60 4.23

Weil drained loamy sand T irr. 49.6 6.75 6.48 6.51 - irr. 38.6 4.95 6.50 6.44

relative humidity. A disinfection of the rhizomes is then required. The application of a 0,1 % solution of carbendazim gives good results.

At this moment, an important problem is the regrowth in the open field of the used rhizomes. An average 10ss of 75 % occurs, but this might be reduced to less than 20 %.

2. WHITE SPEAR PRODUCTION

Rhizomes are harvested in the field and put in a 35 cm deep con­tainer, partly filled with prepared and fertilized peat. plant density can be very high, up to more than 100 per m 2, depending on the size of the rhizomes. The containers can be stacked in the growing room, where a high relative humidity is required. At a temperature of 20oC, the first spears are harvested af ter 10-12 days. Yield may then con­tinue for 4 weeks. Hence, the same room can be used more than five times during one season.

The room temperature affects the growth rate of the spears. At 180C

Table 4

Spear diameter at different growing temperatures

- Room temp. (OC) e.v. Limbras 18 Zl V 2 e.v. timbras 22 Zl V 2 spear </> in mm spear </> in mm

18°C 9.49 8.43 22°C 7.21 7.55 26°C 7.15 7.21

18°C 8.21 8.00 22°C 5.45 6.26 26°C 5.91 5.73

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a mean daUy increase in length of 3.7 cm is recorded versus 9.4 cm at 26°C. Small spears grow faster than thicker ones. Spear diameters, also depend on the temperature during the growing period (tabie 4) .

. An alternative production method might be in hydroponics. In pre­liminary studies yield and quality are rather good with a nutrient fUm technique (NFT). The aeration of the nutrient solution in the NFT gullies give no problems and the regrowth of the used rhizomes in this system is better.

3. RESULTS

3.1. Influence of rhizome size

The size of a rhizome is mostly a function of the age of the plants. Since less large i-hizomes can be placed in a container, the production per m 2 of the growing room is smaller for older plants. In table 5, yield per m 2 is given at different ages.

Table 5

Yield per m2 for rhizomes (e.v. Limbras 22) at different ages

Variant Prod./ Sp. ~ (mm) Number of Sp. prod./m2

pI. (g) rhizomes/ m 2 (kg)

1 year on the field 39 5.25 200 7.8 2 " " " " 128 6.76 100 12.8 3 " " " " 205 6.78 40 8.2

The maximum production is obtained with three year old plants (one year seedlin~, two years transplanted in the open field). The total yield of 13 kg/m is in any case sufficient. Only the spear-diameter must be inlproved as a commercial mean size of 10 mm is required. The production per plant should attain about 200-250 g. Therefore, a suitable method for raising rhizomes in two years must be found through a selection of appropriate cultivars and irrigation with a nutrient solution.

3.2. Influence of room temperature on the production

Room temperatures have an important effect on the total plant yield (tabie 6). Highest productions are mostly found at a temperature of 26°C.

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Table 6

Asparagus produetion at different room temperatures

e.v. Limbras 18 Zl V 2 e.v. Limbras 22 Zl V 2

Room. temp. Sp. prod/pl Number of Sp. prod/pi. Number of (g) sp./pi. sp./pi.

18°C 53.9 5.5 44.3 6.4 22°C 89.6 11.7 79.1 9.3 26°C 143.7 17.6 123.0 15.5

18°C 47.8 10.5 42.3 8.3 22°C 86.7 24.7 57.2 21.0 26°C 83.8 22.1 83.1 25.1

3.3. Influence of growth regulators

In the first experiments effects were tested of gibberelline (KGA3 in concentrations 10-4 , 10-5 and 10-6 M), auxine (IAA in concentra­

tions 10-4, 10-5 and 10-6 M), cytokinine (kinetine in concentrations

10-5,10-6 and 10-7 M), and ethylene (ethre1 FI0) in concentrations

of 10-3,10-4 , and 10-5 M, on the spear production. A positive effect of IAA, ethylene and kinetine was hereby found, mainly by an in­crease in the number of spears per rhizome. The kinetine treatment gives spears of poor quality (open top of the spear). The gib berelline treatment resulted in a lower production. Experiments are continuing with ethylene in order to improve both spear diameter and spear quality.

4. QUALITY

Commercially attractive yie1ds can only be achieved by the produc­tion of straight thick spears without purple colouring, and with a weIl closed top, a good taste and little fibrousness. Up till now, the mean size of harvested spears from three year old plants is still unsatisfactory (6-8 mm) and has to be improved to 10-12 mmo Taste and colour do not give difficulties. Spear tops, however, are of ten of poor quality for they are too open. A sandy surface layer of 7 cm above the rhizomes improves quality of the spear tops to an acceptable level.

5. CONCLUSION

It is possible to produce all-year-round white asparagus in dark climatized rooms under controlled conditions. A total yie1d of 13

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kg/m2 is satisfactory. The mean spear diameter must however be im­proved to more than 10 mmo Optimal environmental temperature is about 20oC. Irrigation in the open field with an appropriate nutrient supply gives good rhizomes af ter a two year growing period. Effects of ethylene on the radial growth of asparagus are studied.

Summary

In 1978, the Research Cent re for Hydroponics of the University of Leuven (Belgium) started a project on the possibility of year-round producing white asparagus spears in dark climatized rooms. Optimal environmental temperature was found to be about 200 C. Yields of 13 kg/m2 we re satisfactory, but the mean spear diameter must be improved to more than 10 mm for a commercially attractive yield. Good rhizomes can be obtained af ter a two year growing period in the field. Effects of ethylene on the radial growth of the spears are studied.

La production d'asperges en containers

Résumé

Depuis 1978, Ie Centre de Recherche pour I'Hydroculture de l'Université Catholique de Louvain (Belgique) examine la possibilité d'une production continue d'asperges dans des locaux dimatisées. La température ZI'timale doit se situer autour de 200 C. Une production d'asperges de 13 kg/m est certainement satis­faisante, mais pour une production commerciaie, Ie diamètre moyen des turions devrait dépasser Ie 10 mmo Après une periode de croissance de deux ans sur Ie champ de bonnes greffes peuvent être récoltées. L'effect d'éthylène sur Ie déve­loppement radial du turion est étudiés.

De aspergeteelt in containers

Samenvatting

Sinds 1978 werd op het Studiecentrum voor Hydrokulturen van de Katholieke Universiteit te Leuven (België) een projekt gestart met het doe~ de mogelijkheid te onderzoeken om het jaar rond asperges te produceren in donkere, geklimatiseerde ruimten. De optimale omgevingstemperatuur hiervoor blijkt ongeveer 200 C te bedragen. Een produktie van 13 kg asperges per m2 is zeker voldoende, maar voor een goed verkoopbare produktie zou de gemiddelde stengeldiameter meer dan 10 mm moeten bedragen. Na een groeiperiode van twee jaar op het veld, kunnen goede wortelstokken geoogst worden. De effecten van ethyleen op de radiale ste~gelgroei worden momenteel nog bestudeerd.

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BOEKBESPREKINGEN COMPTES RENDUS

Pédologie appliquée By J. Boulaine, éd. Masson, Paris, 1980,220 p., 150 FF. ISBN 2-225-64350-4 Commandes : Masson, 120, Rlvd. St.-Germain, 75280'Paris Cedex 06, France.

Ce livre donne un aperçu des différentes étappes du travail pédologique dès la discussion du contrat jusqu'à l'interprétation des données cartographiques.

La première partie du livre dresse un tableau succint des concepts pédologiques et pose d'une manière théorique, souvent originelIe et même philosophique une série de problèmes liés à la cartographie, notamment en présentant les démarches d'un opérateur pédologue en dialogue avec une boîte noire symbolique.

La deuxième partie constitue la section centrale du livre et est surtout consa­crée aux problèmes qui gravitent autour de la réalisation des Glrtes de sol. 11 s'agît de la préparation et du déroulel1?-ent du travail de cartographie (chap. 111, IV et V), des problèmes d'échelle et de la précision (chap. VI) et de la nature et définition des unités cartographiques (chap. VII). Cette section comporte égale­ment un chapître VIII traitant les techniques annexes de la cartographie (télédé­tection, relation géomorphologie-sols et cartographie automatique par ordina­teur). Enfin viennent des considérations sur la prospection des eaux souterraines et sur les méthodes géophysiques, dont la liaison avec la pédologie est nettement moins claire.

La troisième partie du livre est consacrée à l'application de la pédologie et plus particulièrement (1) à l'évaluation qui consiste a porter unjugement de valeur sur Ie sol en fonction d'un système de réference (2), à l'adéquation qui correspond à la recherche de sols aptes à une spéculation donnée ou d'une spéculation possible dans des sols donnés, et (3) à l'optimisation qui consiste à modifier la nature du sol afin d'en rapprocher les caractères de ceux d'un modèle idéal et de Ie rendre capable d'une productivité plus élevée.

L'ouvrage est abondamment illustré et contient une bibliographie importante incluant la plupart des travaux réalisés par les pédologues français en métropole et dans Ie monde.

W. Verheye

Introduction to the Study of Soils in Tropical and Subtropical Regions By P. Buringh, ed. PUDOC, Wageningen, 1979, 146 p., 25 Dfl. ISBN 90-220-0691-3 Orders tu PUDOC, POB 4, 6700 Wageningen, Nederland.

In this third revised edition the author gives a broad idea on what soils of the tropics and subtropics are, how they are classified and what is their evaluation for agricultural use. As is mentioned in the preface this book is written for young soil scientists and specialists in related subjects, and it does not aim to give an overall and detailed inventory of tropical and subtropical pedology.

In the two introductory chapters the role of soil science within land use studies is defined and the different aspects of pedology are outlined. Chapter 3 discusses all relevant soils as presented on the new FAO-UNESCO soil map of the world; the main properties, characteristics and agricultural evaluation are presented (chapter 4 and 5). Moreover , the classification of these soils in the USDA - Soil

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Taxonomy system is indicated (chapter 6). In addition, special chapters deal with land use, agricultural productivity, soil erosion, soil improvement and land evaluation aspects.

The hook includes also a list of former soil names and their approximate equivalent in modern classification systems. Finally, the main soils are illustrated hy sixteen colourprinted photographs of representative profUes.

Red.

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SOMMAIRE INHOUD

G. M. Higgins & A. H. Kassam The FAO agro-ecological zone approch to determination ofland potentiai ', 147

c. Sys Evaluation of soil and landscape criteria with respect to land-use potentials in Europe 169

N. Gerbier L'agrométéorologie, domaine, objectifs et moyens 191

J. Lee State of knowledge and problems related to the defmition and delimination of farming systems and land utilization types in Europe 207

J. Vandamme, K. Van Nerum, A. de la Kethulle & D. Lamberts The suitability of soils for bush beans (Phaseolus vulgaris L.) 243

T. Deckers & D. Lamberts Production of white Asperagus in containers

Boekbesprekingen - Comptes rendus

D/1981/0346/3

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