EFFICIENCY OF MINERAL FERTILIZERS AND MUCUNA ON THE IMPROVEMENT OF THE YIELD OF MAIZE IN ZIMBABWE

In Zimbabwe farmers use sub-optimal amounts of fertilizers due to cash limitations and poor access to fertilizer markets, hence the need to integrate legumes like mucuna (Mucuna pruriens) into their cropping systems. In this study, the effect of P and N along with different mucuna management options was investigated on the yield and yield components of maize. The experimental design was a split - split- plot with two P rates (0 and 40 kg P ha^-1) applied to a preceding mucuna crop, four mucuna management options [1) fallow (F), 2) mucuna ploughed in at flowering (MF), 3) all mucuna above ground biomass removed at maturity and only roots were ploughed in (MAR) and 4) mucuna pods removed and the residues ploughed in (MPR)] and four N treatments [N0 = 0, N1 =40, N2 = 80 and N3 = 120 kg N ha^-1respectively] applied to a subsequent maize crop. The various crop parameters like grain yield, cob length, number of grains per cob, cob diameter, 1000 dry grain weight, stalk weight and harvest index of maize were determined. Phosphorous application improved mean maize grain yield from 2.29 t ha^-1 to 2.34 t ha^-1. The MF and N3 treatment combination resulted in the highest maize grain yield. The MF and MPR and N0 treatment combinations resulted in similar grain yields when compared with F and MAR management options and N3. Other parameters followed similar trends. The MF and MPR management options could, therefore, save 80 and 120 kg N ha^-1for smallholder farmers without sacrificing yield.