Manuel pratique du semis direct à Madagascar - Volume I Chapitre 2 La gestion des écosystèmes cultivés en semis direct sur couverture végétale permanente
Manuel de gestion des SCV sur couvertures vivantes ou mortes, visant la production de biomasse grâce à des successions et associations de cultures ayant un rôle de pompe biologique, améliorant structure et fertilité sol, et recherchant l'intégration agriculture/élevage.
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 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.
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.
Diaporama présentant les problèmes malgaches: érosion et feu de brousse entraînant perte de fertilité , climats et géographie; GSDM et SCV avec historique et résultats jusqu'à diffusion
Developing and maintaining water control in paddy fields is difficult, costly and requires sufficient water reserves. Thus, even in the main rice growing area of Madagascar, the Alaotra lake region (800 metres above sea level), only 30 000 ha of paddy fields can be properly irrigated when over 70 000 ha will remain under poor water control. In these fields, traditional techniques based on irrigated cropping practices are very unreliable: late transplanting (which can be done only when sufficient water is available) and occurence of dry conditions at the end of the plant cycle lead to usually low yields (0.8 to 1 t/ha on average) and production is very unreliable (from nil, during the dry years to 3t/ha when rains are favourable), which makes crop intensification very hazardous. For such situations, a change in paradigm is proposed: abandoning irrigated practice and making the choice of growing upland or ",poly-aptitude", rice varieties (SEBOTA) with agro-ecological practices adapted to the specific field water regime.
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.
In Madagascar Highlands, population pressure and intensive rice cultivation in the
lowlands has led to cultivation on the fragile, low fertility soils of the hillsides.
Fertilisation being limited, yields remain low while erosion leads to paddy field
silting-up and destruction of downstream infrastructures. To overcome these problems, experiments on direct planting on permanent soil cover (DPPSC) have been conducted since 1991 in the Andranomanelatra farm and since 1994 in farmers' fields, covering a wide range of biophysical and socio-economic situations