The Lake Alaotra basin, surounded by high hills, is one of Madagascar’s primary rice producing regions, with over 100,000 hectares of rice fields. The region, is known as the "Malagasy rice granary". It produces an annual surplus of rice, and plays an important role in inter-regional trade, serving as a critical supplier of rice for the country’s capital Antananarivo, and largest port city, Tamatave. Rice production of the Alaotra was greatly enhanced through the hydro-agricultural schemes managed by SOMALAC (Société Malgache d'Aménagement du Lac Alaotra) in the 1960s and 1970s (Devèze, 2007). For 40 years, the demographics of the region have been marked by the

The Lake Alaotra basin, surounded by high hills, is one of Madagascar’s primary rice producing regions, with over 100,000 hectares of rice fields. The region, is known as the "Malagasy rice granary". It produces an annual surplus of rice, and plays an important role in inter-regional trade, serving as a critical supplier of rice for the country’s capital Antananarivo, and largest port city, Tamatave. Rice production of the Alaotra was greatly enhanced through the hydro-agricultural schemes managed by SOMALAC (Société Malgache d'Aménagement du Lac Alaotra) in the 1960s and 1970s (Devèze, 2007). For 40 years, the demographics of the region have been marked by the high rates of immigration of farming families attracted to the wealth of the region. High population growth,has tripled the population since 1960 (and is doubling it every 18 years) leading to land tenure saturation and an increasing pressure on natural resources (Durand et Nave, 2007). Land tenure is saturated in low land areas (Irrigated Paddy Fields (IPF), Poor Water Control Paddy Fields (PWCPF) and baiboho). Therefore, when seeking new land for cultivation, farmers tend to expand onto uplands, the tanety (hills), previously under- developed or reserved for grazing herds (Domas et al., 2009). Deforestation, repeated burning, and the exclusion of fallow periods have accelerated natural erosion processes in these degraded and fragile soils,, resulting in an alarming loss of soil fertility, siltation of downstream irrigation canals, and declining yields to fisheries. Today, on 30, 000 hectares of rice fields developed by the SOMALAC, between 10,000 and 15,000 hectares are currently under good water control (Durand and Nave, 2007). In the context of increasing degradation of natural resources, research and development programs (both Malagasy national and French) have set up projects for the extension of agro- ecological techniques, based on the principles of conservation agriculture (CA). Direct mulch cropping (DMC) is one of these techniques, introduced in the Lake Alaotra region in the 1990’s, with the objective of introducing new cropping systems to improve yields while preserving natural resources. Having encountered many problems (constrained access to inputs, technical complexity that is overwhelming for small farms), the adoption of CA grew significantly since 2000 with the launch of the project “Mise en valeur et protection des Bassins Versants du Lac Alaotra » (BVLac). The project, started in 2003 and was conducted in two phases over a period of five years each, from technical advisory at the field scale, to a holistic approach at the farm scale