Improved soil fertility in Benin

Farmer groups in Benin have found that the leguminous ground creeper, mucuna, serves two purposes: it suppresses pernicious weeds and builds up soil fertility. In the late 1980s, the Institut National des Recherches Agricoles du Benin (INRAB) began to encourage farmers to develop their own techniques for improving soil fertility. They found that maize yields were improved when the crop was planted after Mucuna pruriens, otherwise known as the velvet bean. However, the farmers were more impressed with the way mucuna suppressed speargrass (Imperata cylindrica). Infestations of speargrass were forcing subsistence farmers to abandon their land. Apart from using expensive chemicals, there was no way to rid the land of the pest, until they found mucuna. First the speargrass has to be slashed down, then the mucuna is planted. It rapidly develops a thick canopy which shades out the weed. During the dry season the mucuna dies down, and is left to act as a mulch and a source of nitrogen for the following maize crop. Since 1990, INRAB, with support from the International Institute of Tropical Agriculture (IITA), has promoted mucuna in other other of Benin. Research showed that as an intercrop to improve soil fertility, mucuna can supply as much nitrogen as one 50kg bag of urea per hectare. After three years, it was reported that more than 3000 farmers in the five southern provinces of Benin were using mucuna, either to control speargrass or as an intercrop to improve maize yields. IITA PMB 5320 Ibadan NIGERIAFarmer groups in Benin have found that the leguminous ground creeper, mucuna, serves two purposes: it suppresses pernicious weeds and builds up soil fertility. In the late 1980s, the Institut National des Recherches Agricoles du Benin (INRAB) began..