Experimental assessment of innovative slash and burn cultivation practices for sustainable land-use and deforestation prevention in Central Menabe, Madagascar (AGRIFEU)

Madagascar is recognized as one of the main biodiversity hotspots on earth and pressure on ecosystems is increasing over the years due to a rapid deforestation. So far, politics and NGOs blame rural households as the cause of natural habitat loss because of their practice of slash-and-burn agriculture. Nevertheless, from the point of view of local communities, these practices are a way to preserve soil fertility as long as traditional rules are respected and in turn they blame “migrant” communities, which settled about 50 years ago in the region, for unsustainable slash-and-burn practices. Therefore, the main challenge this project will address is the reunification of the different stakeholders by showing that traditional practices and nature conservation can co-exist. The project is an attempt to bring together different stakeholders for exploring experimentally alternative practices such as selective slash-and-burn, which could represent a first step to develop management strategies that will balance conservation and development and thus allow for more sustainable land use and reduce deforestation in Central Menabe, Madagascar.

We intend to test the following hypotheses:

• Some specific local trees that have been shown to be major contributors to biomass in secondary vegetation and have favorable mineral content (like Pourpartia sylvatica and Tarenna Sericea) can be used to produce organic fertilizers by means of compost transformation.
• Selective slash-and-burn practices can improve the socially and environmentally sustainable use of the land when coupled with agro-ecological methods. ​
• Potential socio-economic impacts of the method should be high as the techniques stay close to the traditional practices, will build upon local practices, and will respect local drivers and constraints.

Four specific objectives will be pursued:

• To elicit local ecological knowledge, drivers and constraints related to the soil/cultivated plant/tree system and the slash-and-burn practices.
• To characterize the soil-cultivated plant system for the main local crop (maize).
• To assess the potential of fertilization with compost made of selected local trees, and the constraints of composting.
• To determine the best combination of vegetation cover (gradient of tree cover remaining in the field after selective slash-and-burn), soil preparation-tillage and composting (green leaves and small branches from selected trees) for a sustainable and socially acceptable agro-ecosystem. ​

The research seeks to increase household outcomes and preserve at the same time the primary forest. In the medium and long-term, it seeks to lower the impact of slash and burn practices on biodiversity as well as to develop means for facing the impacts of climate change on ecosystems.

​Expected outputs can be listed as follows:

• A more susta inable slash-and-burn technique
• Increased crop yields
• An optimized and better controlled crop production system for rural households
• A reduced need for new soils from deforested areas
• ​​In the medium-term, a preserved environment that benefits both biodiversity and the local econo my

The improved slash-and-burn technique is supposed to have a better efficiency than current practices: it aims at maintaining the soil fertility and thus producing more crops for a longer period on less arable land. As the project is based on experiments and not observations, results will be quantitative and ready to use. Studied techniques are easy to implement, made with local techniques and local materials, thus they should meet a high social acceptance. ​

Madagascar

• Link to project ​ on SNSF research database P3