Contributions of Agroforestry Research to Livelihood of Smallholder Farmers in Southern Africa: 1. Taking Stock of the Adaptation, Adoption and Impact of Fertilizer Tree Options

Abstract

Agroforestry practies involving fertilizer trees managed in sequential and simultaneous tree-crop systems are key to achieving sustainable food production in Southern Africa as they offer a wider scope for resource-stressed farmers to produce sufficient food for consumption and markets, even where land scarcity and soil fertility are major constraints. In these systems, maize yields have generally increased from less than a tonne per hectare to two or more tonnes, in Malawi, Tanzania, Zambia and Zimbabwe and they have been shown to be comparable to fertilized fields. Application of micro doses of inorganic fertilizers (especially N) in tree-crop systems has generally increased the synergy in nutrient availability thereby producing higher maize yields than unfertilized maize. Fertilizer tree systems are more productive and economically more profitable than unfertilized maize system and the economic impact is high, estimated at US$ 2 million in 2005 for Zambia alone. Fertilizer tree systems practiced on a 0.20 ha area increased maize consumption for a family of five by extra 57-143 days. Training of trainers, farmer-to-farmer extension and support to existing initiatives were the most effective pathways of disseminating proven technologies. Impact assessment studies in Malawi, Mozambique and Zambia indicate that 66-83% of farmers are aware of the contribution of fertilizer tree systems to food production, cash income, fuelwood and their overall livelihoods. However, the slow rate of adoption of fertilizer tree options under farmer's resource-poor conditions underscores the magnitude of the challenge for stimulating long-term investment. There is need to create enabling policy support that would make quality germplasm available in the right amount and time and provide awareness and training to farmers on such knowledge-intensive technologies.