Modelling resource competition and its mitigation at the crop-soil-hedge interface using WaNuLCAS

Publikations-Art

Zeitschriftenbeitrag (peer-reviewed)

Autoren

Hussain K, Wongleecharoen C, Hilger T, Ahmad A, Kongkaew T, Cadisch G.

Erscheinungsjahr

2016

Veröffentlicht in

Agroforestry Systems

Band/Volume

90/

DOI

10.1007/s10457-015-9881-z

Seite (von - bis)

1025–1044

Schlagworte

Agroforstwirtschaft, Alleeanbausysteme, Mais, Nachhaltigkeit, Phosphor, phosphorus, Stickstoff

Agroforestry systems have a large potential to increase systems' productivity and
provide soil conservation in hilly terrain but comprise complex interactions at the cropsoil-
tree interface. Modelling can be an operational approach to unravel the later. We
used the spatially explicit, dynamic Water Nutrient and Light Capture in Agroforestry
Systems model to (i) predict maize above ground biomass (AGB) and interactions at
the crop-soil-hedge interface, (ii) improve our understanding of trees' impact on crops
in alley cropping, and (iii) identify mitigation strategies. A 2-year-data set from a soil
conservation experiment in Western Thailand with maize farmers' practice
(monocropping, tillage), maize-chili-hedgerow intercropping (± fertilization; minimum
tillage) was used as model input. Model validation showed satisfactory results for
maize AGB (R²=0.76, root mean square error=4.2, model efficiency=0.69). Simulations
revealed nitrogen (N) and phosphorus (P), rather than light and water, as main limiting
factors at the crop-soil-hedge interface reducing maize AGB in rows close to
hedgerows. Growth limitation by P was stronger than that of N while light competition
was alleviated by four to six hedgerow prunings already. WaNuLCAS simulations
clearly indicated that small-targeted additional N and P dressings to maize in rows
close to hedges helped overcoming nutrient competition. Such strategic management
options can be done for local farmers' and hence, foster adaptation of soil conservation
techniques for sustainable crop production in future.