PERFORMANCE AND PRODUCTIVITY OF COMPONENT CROPS IN LEGUME-UPLAND RICE INTERCROPPING SYSTEM AS INFLUENCED BY ZINC RATE

The application of zinc to some selected legumes (cowpea - Vignaunguiculata L. Walp., soybean – Glycine max L. Merr. or mungbean - Vigna radiate L. Wilczek) intercropped with upland rice (OryzaesativaL.) may improve the presence of residual nitrogen in the cropping system andprotein in-take of farmers faced with protein and mineral deficiency, especially zinc in their daily food menu. Information on the effect of zinc on legumes and rice is inadequate. The study investigated zinc rate effectsonshoot zinc status, grain yieldand productivity of the crop species in sole and intercrop with upland rice. There were three separate trials laid out in a randomised complete block design with three replications. Zinc rate (0, 2, 4 and 6 Kg•ha^-1) were applied to the sole and intercrop in the trials. Intercropping legumes with rice exhibited a high degree of complementarity. On average, 2 Kg Zn•ha^-1 gave the highest total land equivalent ratio (LER 1.89) in soybean/rice, followed by 4 Kg Zn•ha^-1 (LER 1.64) in mungbean/rice compared to other zinc rates.The application of 6 Kg Zn•ha^-1 in cowpea/rice intercrop gave the highesttotal gross monetary and net returns (NR) but lowest benefit–cost ratio (BCR) compared to the other trials at the same Zn rate.In mungbean/rice intercrop,highest NR (₦263692:77•ha^{−1})and BCR(0.90) were exhibited at 4 Kg Zn•ha^-1. The application of 4 or 6 Kg Zn•ha^-1in intercropping to the selected legumespecies with upland rice enhanced productivity and financial returns in the systems.