In order to put in place a suitable advisory system, in an integrated approach at the terroir level, it is necessary to master a range of cropping systems adapted to local conditions. This requires identifying the nature of the most appropriate crops and the order of their succession and/or association, as well as the operational sequence to be applied to these crops or crop associations.
Based on the understanding of soil/plants/microorganisms interactions and the importance of the primary biomass production in the functioning of the soil system, OMC introduces multifunctional cover crops, growing intercropped or in sequence with the main commercial crop. The introduction of cover crops leads to better utilization of available natural resources, maximization of biomass production and higher organic restitutions to the soil system.
Version portugaise des chapitres 1 et 2 du Manuel pratique du semis direct à Madagascar, présentant les principes, le fonctionnement et la gestion des systèmes en SCV.
Version espagnole des chapitres 1 et 2 du Manuel pratique du semis direct à Madagascar, présentant les principes, le fonctionnement et la gestion des systèmes en SCV.
Experiments conducted in the 1990's in various ecological zones of Madagascar allowed to propose a large range of cropping systems based on direct seeding on permanent soil cover (DSPSC). To propose solutions and face the many constraints of Malagasy farmers, a unique set of references was developed, for various agro-ecological and socio-economic conditions, with different levels of intensification and risk (Séguy, 2005). However, although the proposed systems had demonstrated their high agronomic, environmental and economic performances, and proved to be sustainable, their extension remained limited'until the beginning of the 21st century. Main reasons identified to explain this situation, apart from the limited financial resources consecrated to this task, were the very limited human resources and the lack of an approach for extension of knowledge intensive systems, in a difficult environment: subsistence agriculture, smallholders with limited investment means, degraded soils, poor infrastructures, etc. (GSDM, 2004)
Sur les Hautes-Terres de Madagascar, l'augmentation de la pression démographique et la saturation des bas-fonds rizicoles entraînent une surexploitation des collines aux sols fragiles. Les techniques de culture traditionnelle, telles que le labour manuel, conduisent à une érosion intense, à une baisse de la fertilité et des rendements, qui condamnent à terme cette agriculture de subsistance. Pour surmonter ces problèmes des expérimentations en semis direct sur couverture permanente (S.C.V.) ont été conduits depuis plus de 10 ans par TAFA et le CIRAD, couvrant les diverses situations de la région. Après maïtrise de la reproductibilité des systèmes face à une variabilité climatique suffisante, ils sont diffusés au niveau des terroirs villageois afin de les intégrer aux règles de gestion communautaire, d'élaborer un référentiel technico-économique et de former les partenaires pour leur diffusion.
Agriculture in Madagascar has to face tremendous constraints: very low investment capacity, poor infrastructure network, low availability and high prices of inputs, uncontrolled bush fires and deforestation leading to severe erosion, loss of arable land and destruction of downstream infrastructures.
As a consequence, yields are low and farmers' condition very precarious.
Techniques of direct planting on permanent soil cover (DPPSC) can lead to
solutions for sustainable and profitable agriculture.