Effect of fertilizer treatments and planting time on the yield of some grain legumes of the benue river basins of Nigeria

Abstract

A selection process for an ideal cover crop for yarn, maize, and cassava was initiated in 1993 cropping season in Makurdi, Nigeria. Four types of food legume crops grown locally were selected for the trials. The yield potentials of akidi (Phaseolus vulgaris), ground akidi (Sphenostylis stenocarpa), odudu (Phaseolus lunatus), and kafanji (Vigna unguiculata) were evaluated in two cropping seasons and under conditions where either no fertilizers, 50 kg nitrogen‐potassium‐phosphorus (NKP)/ha or 21 kg P/ha from single superphosphate (SSP) source were applied. The crops were planted in April and repeated in August of the same year in a 4 x 3 factorial in a split‐plot design. Fertilizer NKP generally increased the grain yield of all the crops significantly. The yield differences due to P fertilizers for odudu and akidi were not statistically significant (P=0.05). The P fertilizer resulted in significant increases in the grain yield of kafanji (from 1.113 to 1.7 mt/ha) and ground akidi (0.97 to 1.27). The biomass, root systems, and nodule yields were also increased proportionally by P application for all the legumes. No significant yield differences was observed between early and late crops in grain yield when no fertilizer was used. However, the crops produced about 30–40% less nodules, biomass, and root yield due to late planting (August).