Agronomie 24 (2004) 383-395
DOI: 10.1051/agro:2004029

Modelling crop residue mulching effects on water use and production of maize under semi-arid and humid tropical conditions

Eric Scopel^a, Fernando A.M. Da Silva^b, Marc Corbeels^a, François Affholder^a and Florent Maraux<sup>c

a</sup>  Agrosystems Programme, Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), avenue Agropolis, 34398 Montpellier Cedex 5, France
^b  Centro de Pesquisa Agropecuária dos Cerrados (EMBRAPA-CPAC), CP 08223, 73301-970, Planaltina, DF, Brazil
^c  Agronomy Programme, Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), avenue Agropolis, 34398 Montpellier Cedex 5, France

(Received 12 June 2003; accepted 10 May 2004)

Abstract - A key principle of direct seeding mulch-based cropping systems is the retention of crop residues on the soil surface to preserve soil water for crop growth. In this study the impact of surface crop residue on water use and production risk associated with rainfall variability is analysed for two contrasting tropical sites. The two sites are La Tinaja in semi-arid Mexico and Planaltina in humid Brazil. The crop growth model STICS, version 3.0 was updated with a simple empirical module, incorporating the following effects of surface residue on soil water balance: (1) rainfall interception and subsequent mulch evaporation; (2) radiation interception with associated reduction of soil evaporation and (3) reduction of surface water runoff. The results of the model simulations showed that the effect of radiation interception at both sites was much more important than the effect of intercepting rain. The high sensitivity of model yield predictions to surface water runoff, especially in La Tinaja, highlighted the importance of a careful parameterisation of the surface water runoff formalism. The model results suggested that even small amounts of surface residue are effective at reducing water loss and increasing yield. In La Tinaja, grain yield was increased at least two-fold with retention of 1 Mg ha^-1 surface residue. In Planaltina, the advantage of water conservation by surface residue is partly offset by increased drainage losses. As a consequence, the impact of crop residue mulching on grain yield was lower at that site.

Key words: crop growth model / mulching / climatic risk / surface residue / water balance

Corresponding author: Marc Corbeels Marc.corbeels@cirad.fr

© INRA, EDP Sciences 2004