Model based evaluation of
cover crops for banana cropping
systems
Tixier, P., Ripoche, A., Achard, R.
Banana and plantain Research Unit, Martinique, France
Contact: [email protected]
Intensive systems were traditionally managed with bare soil
Cover crop allows to mitigate herbicide applications and erosion
Why cover cropping in banana cropping systems ?
Cover cropping banana alters the functioning of the soil-plant system
Shading
Competition for mineral resources
0 50 100 150 200 250 300 m a m j j a s o Month H e ig h t (c m ) T0 T1 T2
But cover crop alters crop cycle
And delay harvest up to 8 weeks
Bare soil
Cynodon dactylon Bracharia decumbens
Cover crop should satisfy multiple criteria
Host status for pests Capacity to cover soil surface
Commercial availability of seeds
Authorization of importation
Minimize competition for water and nitrogen Capacity to
compete weeds
Tolerate shading of the main crop
How to select the best cover crops ?
Select most promising species of cover-crops on the base of early
measures in collections
3 main criteria
Capacity to control weeds Do no compete the
banana plants for nitrogen Be tolerant to shading from
A model based approach
A simple growth model
Radiation interception Biomass allocation Biomass conversion Banana canopy
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 5 10 15 20 25
Weeks after sowing
B IO M (t) ( Ton ha-1) sp. CD n = 5 RMSE = 0.080
A model based approach
Calibration using data of growth under different shading
Simulation of the growth of cover-crop under the canopy of banana
0 1 2 3
0 20 40 60 80 100 120 140
Weeks since seeding
BI O M(T ) (kg m-2 ) BD CR PN SH SG PP NW DR
3 indicators were defined on the base of :
- biomass in 15 first weeks of growth Weed control
- biomass between 50 and 150 weeks Persistence under the shade - total demand of nitrogen N competition
BD DR NW PN SH AO CR CD PP SG MA 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.0 0.1 0.2 0.3 0.4 0.5 0.6
Selection for multiple criteria
Capacity to compete weeds
Aboveground biomass Kg/m²
Competition for nitrogen
Nitrogen demand Kg/m²
Tixier et al. 2011. Eur. J. Agron.
Let’s go further
Use of a spatialized model to determine the optimal cover crop and fertilization management
A tool useful for early selection of promising cover crop species
Thank you for your attention
Glycine javanica
Gramineous impatiens
