Nitrogen-fixing cover crops, or “green manures,”
Successive government subsidy programs supporting the purchase of inorganic fertilizers have contributed to short-term yield gains. However, synthetic fertilizer application has negatively affected the soil - low nutrient holding capacity, high acidity, low organic matter, poor soil structure, low water-holding capacity. In addition, when it is not subsidized, synthetic fertilizer is prohibitively expensive.
Nitrogen-fixing cover crops, or “green manures,” and edible legumes have long been promoted as an important strategy for enhancing yields, promoting human nutrition, and conserving soil quality in low-input smallholder farming systems. However, subsistence farmers in Malawi produce few legumes and the use of these crops is steadily decreasing. Resource poor farmers are willing to grow legumes, but labor requirements, limited access to appropriate seed varieties, uncertain markets, and limited technical education are barriers to more intensive legume uptake.
Unlike conventional “top down” technology transfer extension models, the success of this
legume diversification project underscores the importance of participatory research and extension
methodologies to address the complex social factors—community needs, gender dynamics,
access—that influence new technology adoption in agriculture.