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Tree – Soil – Crop

MK Lanskap Perdesaan dan Pertanian

InteractionsTim Dosen:

Prof. Dr. Hadi Susilo ArifinProf Dr Wahju Qamara MugnisjahProf. Dr. Wahju Qamara Mugnisjah

Dr. Kaswanto

Departemen Arsitektur LanskapProgram Pascasarjana IPB

2014

Tree–Soil–Crop Interactions

Meine van Noordwijk Kurniatun Hairiah

TreesTrees

Sun light

Crops

LitterLitterLitterLittera

b

cc

a

Negative effectsa = shadingb = root competition

Positive effectsc = Litter falld = deep roots of trees

act as ‘safety-net’

d d d

Tree-soil-crop interactionsUnderstanding tree-annual crop interactions strongly determines the results of the transition into agroforest: success or failure! The overall interactions can be positive ( d t ) ti (di d t )(advantageous) or negative (disadvantageous).

Disadvantageous interactions• Competition for light: shading by trees, reducing light

intensity at crop level• Competition for nutrient and water: shallow tree rootCompetition for nutrient and water: shallow tree root

systems are likely to compete with crops for nutrient and water, reducing uptake by crop roots.

• Trees can be a host for pests and diseases of annual food crops (or vice-versa).

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Advantageous interactions Litter fall and pruned leaves or small branches supply a protective

litter layer and organic matter for the soil A litter layer reduces loss of water from the soil surface by

evaporation and improves the soil moisture regime Shading by trees may suppress weed growth (e.g. Imperata

cylindrica), and reduce the risk of fire spread in the dry season Deep tree rooting systems improve nutrient recycling by acting as a

(1) nutrient safety- net, taking up nutrients which leach out to the subsoil, out of reach for the shallow rooted crops; and (2) nutrient pump, taking up nutrients released from mineral weathering in deeper layers

L t bi l i ll fi it f th t h Legume trees can biologically fix nitrogen from the atmosphere (N2), and supply nitrogen to the soil that decreases the requirement for N fertilizer

Providing a stable microclimate, by reducing wind speed, increasing air humidity, providing partial shade (for instance Erythrina in cacao or coffee gardens)

Peltophorum

(Soga)

Gliricidia

(Gamal)

4 m

Root competition OR useful overlap??

Potential for root competition

Deep tree root systems act as “nutrient pump” or as a “safety-net”

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Hedgerow intercropping during dry season Shading out weeds during dry season

Peltophorum in an Imperata field Litterfall under Peltophorum trees

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Organic layer

Forest soilForest soil

Agricultural soil profile

Leucaena ~1.85 m

Maize root systems

Old tree root channel

Deep tree root systems as “nutrient pump” in fertile soil

Shallow root system of Leucaena

Deep root system of

Maize root

system of Peltophorum

system

Is Jackfruit a drought tolerant tree?

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How to quantify the interaction ?

Parameter Experimental treatment

Shading Without canopy pruning With canopy pruning

Experimental treatments:

py p gCompetition of waterand nutrient

Without root barrier With root barrier

Mulching Without mulch transfer With mulch transfer

Long term residualff t

Without tree removaleffect With removal of complete

hedgerowsTotal plot 8 sub plot per tree species

Root barrier

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Quantifying biomass of tree pruning

Biomass transfer

Biomass transfer

1X2X

Mulch treatment

Mulch transfer

Tree removalremoval

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Control plot ~ No hedgerows

4 level N fertilization:

No fertilizer 45 kg ha-1

90 kg ha-1

4 level N fertilization:

135 kg ha-1

Mg

ha-1

Long term residualS.E.D

Gra

in y

ield

, M

45N

90N

135N

Hedgerow intercropping

0N

Control

8

g ha

-1

2

3

4

5

M l h R t

Residual

C

P P/G

G

L

F

Gra

in y

ield

, Mg

0

1

0

-1

-2

Mulch Root

F

F

P

P/G G

CP

P/G GL C

F

P P/G

GL

C C lli d

Shading

-2

-3C

F

L

C = Calliandra;F = Flemingia;P = Peltophorum;G = Gliricidia;L = Leucaena

Control

F

P/G

G

L P

P/G

LF

C

Dry season

C PP/G

G

Normal Double900 45 135

N application, kg ha-1 Mulch application

Hedgerow of pruned trees

Pruning biomass

B

Two years after tree removal

Aluminium toxicity

A

From a biophysical point of view,

agroforestry systems can only be beneficiary,

if there is at least some

complementarity in resource capture

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Terima KasihTerima Kasih