Impact of legumes intercropping on soil functioning and rubber

physiology

Impact of legumes intercropping on soil functioning and rubber

physiology

Set up of an experimental layout in Buriram

JEAI ECO-RUBBER

Context Context • Our previous work (Marin et al., 2013, Arunee

and Milena 2014) showed that intercropping has an important effect of soil bio-functioning.

• Legumes seems to have an important impact on soil nutrients, tree physiology (N transfer see work of Clermont dauphin), water soil status, weed prevention etc..

ObjectiveObjective

• Compare the effect of legume’s intercropping to cassava intercropping on parameters link to soil and plant functioning

• Select within 3 legumes the most efficient one in terms of N transfer, soil nutrients, soil biodiversity and activities, soil moisture, tree growth etc..

Layout characteristics Layout characteristics •Tree age: 2 years old •Previous crop : Eucalyptus •Crop clone: RITT251)•Plot size: 25 rai (4,2ha)

Measure of the girth Tree girth sizeMade by Tum in May 2014

Choice of legumes !Choice of legumes !Legumes Advantage Inconvenient

Mucuna bracteata Easy to growth Propagation through cuttings (T° and humidity too high in Thailand for seeding)

deep-rooted fast growing moderate drought resistance at the beginning after growing

shade tolerance

grows fast and covers the field very quickly

suppresses all weeds

Nitrogen fixing capacity was found to be high and make it available to the main crop

impedance to beetle breeding

reducing loss of nutrients

Choice of legumes !Choice of legumes !Legumes Advantage Inconvenient

Calopogonium caeruleum Weed control Increase organic matter nutrient cycling efficiencyinhibited erosionreduce fire (in the south)Decrease the day of tappingdrought toleranceshed tolerancereduce management and labor

expensive Cause of fire (shed leaves in the northeast)

Pueraria phaseloides Weed control Cause of fire (shed leaves in the northeast)

Increase organic matter No drought and shed tolerance

Nutrient cycling efficiency High fertilizer using

Inhibited erosion

Layout in 4 blocks Layout in 4 blocks Cassava MUCUNA CALOPOGONIUM PRERARIA Control

Control Cassava CALOPOGONIUM MUCUNA PRERARIA

PRERARIA CALOPOGONIUM Cassava MUCUNA Control

CALOPOGONIUM MUCUNA Control PRERARIA Cassava

Block design Block design

BLOC1BLOC2

BLOC3

BLOC4

Soil sampling 0-5/5-10/ 10-20)

Each plots = 6 lines X 12 tree

Studied Area

Measurements(Christian H, Henri R, Claude H. Nok, Supat) Student ?

Measurements(Christian H, Henri R, Claude H. Nok, Supat) Student ?

• Meteorological records – station Davies or Campbell (here in Bangkok) (Norbert for installation ?)

• Soil physical parameters (Inter- row + row)– Soil resistivity : Henri in September with ETR– Soil water content

• sensor Sentec in each row-inter row (6 PVC tubes/ Plot x 24 plots = 144 tubes

• Mobile sensors (trim pro) : more specific for surface measurements• Soil solution (soil trap) (CH)

– Hydric potential • Tensiometers or psychometrics sensors (Claude H & F.Do)• Do we have some available from BNT ? How many we need for the exp ?

– Others physical parameters :• bulk density, texture ( C.H and LDD Region 5 or LDD Bangkok ?

(Nok.)– Chemistry (soil and water solution)

• pH, Nm , P, K, OM, C ,N, (NIRS ? NoK.

Ecophysiological tree measurements

(Supat, F. Do, P. Thaler, F. Gay) Student ?

Ecophysiological tree measurements

(Supat, F. Do, P. Thaler, F. Gay) Student ?• NPP : Tree girth and length – KU Equipment for tree length available ? (FG) – Periodicity (each 2 months ?) (FG)

• Litter fall (litter trap) – Is it necessary ? What model (for FG and PT)

• LAI (fish-eye)– Could we use LMI-KU equipment ? Who can be involved in the analysis ? (FG)

• Foliar potential – See if Wattman sensors exist in KKU, are they available for this exp ? (Supat and Fred Do) – Who will be in charge (Supat Student ?) (Supat and FD)

• Sap Flow – Pb damage the tree, is it necessary now ? (Supat, FD)

• Mineral content (Supat, F. Do, P.T) – Mg, Ca+, what else ? – Done by Spad ?– Could we use it periodically ?

Measurements at the intercrop(Kiriya and Didier Lesueur) Alain P ? Master Student KKU Wasithi

Measurements at the intercrop(Kiriya and Didier Lesueur) Alain P ? Master Student KKU Wasithi

• Plant Biomass– Shoot Biomass, Root, Nodules What periodicity ? – LAI ??? (not sure to understand ?)

• Microbial (need to be more detailled Kiriya)• Isolation of N fixing bacteria, PSP (How ? ) • PSP

• Roots ? (Alain P ? )

• N2 fixation by the legumes– 15N natural abundance method using samples of

leaves, stems and roots collected each year on the interrank crops

– The non legumes interrank crops will be used as non fixing reference plants for the calculations of Ndfa

– Biomass of each plant compartment at the period of these samplings will be needed for calculations of N2 stocks

N transfert (legumes Tree)(Cathy CD, Kiriya Master student Wasithi ? )

N transfert (legumes Tree)(Cathy CD, Kiriya Master student Wasithi ? )

• Microbial activity and Diversity (PhD Kee+ AlainB ) • Bacterial and fungal biomass • Catabolic profiles• Genetic structure

• Nematodes diversity (Som + Prakaijan)– Free living nematodes – Entomophatogenous

• Soil Fauna Diversity (Som + Chutinan + master ?)

Soil biological diversity(Prakaijan, Chutinan, Alain B., Master student KKU Treenuch promnok (som),

Phd Student LDD Kee

Soil biological diversity(Prakaijan, Chutinan, Alain B., Master student KKU Treenuch promnok (som),

Phd Student LDD Kee

Others ???

Cassava intercropping

Kam khup krap SEE YOU SOON