Estimated yield and nutrient contributions of legume cover crops intercropped with yam,cassava, and maize in the Benue River basins of Nigeria

Intercropping trials were established in the sandy soils of the Benue River Basins of Nigeria to assess the effect of some food legumes used as cover crops in cassava, yam, and maize based cropping systems. The soil productivity and yield contributions of ground akidi (Sphenostylis stenocarpa), pigeon pea (Cajanus cajan), local (Kafanji), and improved (IAR‐355) cowpea (Vigna unguiculata) varieties to the main crops were assessed and presented on a fertilizer‐ equivalent basis. The cowpea varieties and ground akidi helped maize to increase the efficiency of nitrogen (N)‐phosphorus (P)‐potassium (K) fertilizer use by producing an additional 2.74 and 1.59 kg grains/kg, respectively. While an additional six tons of yam tubers was contributed by the kafanji intercrop per hectare, only about three tons was contributed by ground akidi. With the exception of pigeon pea, the test legumes were suitable for use as cover crops for cassava, yam, and maize in the Benue River Basins of Nigeria.