The results from the trials showed the technical and economic feasibility, as well as the social acceptance of cultivation on soybeans and mungbeans under no-tillage after rice. The main role of No-tillage was to allow the cultivation of a second crop after rice, thus taking advantage of the residual soil moisture. However, the system is not yet completely turned into No-tillage, because rice is still being cultivated under conventional system. It is necessary to know which could be the incentives for the farmers to change the system of rice cultivation.

The GP-DMC (direct sowing, mulch-based and conservation agriculture)program is a Global Partnership Program under GFAR (Global Forum on Agricultural Research). It is an international initiative that aims to strengthen the capacity of key stakeholders to develop suitable DMC systems and to accelerate their wide adoption.

Ce poster du réseau DMC (Direct Seeding, mulch based and Conservation Agriculture) a été présenté à la conférence GFAR 2003 de Dakar.

Direct seeding mulch based cropping systems (DMC) form an attractive alternative to combat soil degradation and to sustain agricultural activities in many countries of the world. Since 20 years CIRAD in partnership with several national and international research organisations, contributes to enhance this type of cropping systems through developing new concepts and adapting them to different environmental and socio-economical conditions. Organic matter management is the key factor for the efficient functioning of these systems and aims at maintaining the soil permanently covered and protected by a vegetal mulch. In the humid zones of the tropics where mineralisation of crop residues is rapid due to favourable environmental conditions, it has been necessary to introduce additional cover crops before and/or after the main commercial crops (figure 1). These cover crops have been selected in order to mimic the functioning of the natural forest ecosystem of these regions. Thus, an efficient cover crop is able to rapidly produce biomass even in marginal growing conditions and it has a strong and well developed root system for an optimal use of soil resources. These characteristics permit to produce biomass when climatic conditions are risky (at the beginning or at the end of the rainy season and even during the dry season), maintaining the soil covered through all year. Besides, the cover crop is a means to recycle soil water and nutrients that have not been taken up by the commercial crop, avoiding irreversible nutrient losses by leaching. The concept of “nutrient pumps” applied to cover crops has been fundamental to improve the sustainable production of annual crops with DMC in the humid tropics.

Diaporama sur les concepts du Semis direct SCV avec la multi-fonctionnalité des plantes de couverture