Partnership with Malawian Farmers to Develop Organic Matter Technologies

One of the biggest challenges in the tropics is to develop organic matter technologies (OMT) which increase production, reduce risk and are taken up by farmers. An interdisciplinary team of researchers, extension staff and farmers addressed this challenge in southern Malawi. Two watersheds were identified as the primary unit of research, extension and development to test OMTs. This landscape-based approach provided the platform for interdisciplinary research and farmer-participatory, community based assessment of OMTs. The on-going process involves testing a menu of farmers' OMT recommendations and closely linked process research conducted in the field. The OMT with promise in the maize-dominated cropping system of the watersheds was relay intercropping of agroforestry species ( Sesbania sesban and Tephrosia vogelii). Evaluation of OMT performance involved farmer assessment and biological evaluation. Farmer participatory methods included village group and individual semi-structured questionnaires, linear transect walks, and farmer-managed, researcher-designed trials. Biology included monitoring cropping system production, linked with soil nitrogen dynamics and watershed nutrient budgets to assess sustainability of OMTs. Nutrient budgets indicated that system productivity can be enhanced almost two-fold by addition of 30 N kg/ha N as an organic or inorganic source, and nutrient losses will be lowest with a combined OMT plus inorganic fertilizer technology. The poorest farmers with access to small, infertile fields tended to have sandy soils with low nitrate levels and limited growth of Sesbania. This reduced the benefit from relay OMT systems. These farmers may be candidates for more intensive use of grain legume intercrops and rotations, as benefits from the grain are needed by these food-insecure households, and will complement soil fertility amelioration.