PRODUCTIVITY, NITROGEN FIXATION AND GRAIN YIELD OF LEGUMES INTERCROPPED WITH ROSELLE IN SOUTHERN AND NORTHERN GUINEA SAVANNAH OF NIGERIA

A field experiment was conducted at the Teaching and Research Farm, University of Agriculture, Makurdi, and at the Demonstration Farm, Federal College of Education (Technical), Gombe during the 2012 cropping season to evaluate various grain legumes for productivity, N-fixation and grain yield. Three grain legumes intercropped with a reference roselle were grown in a randomised complete block design (RCBD) with three replications. No fertilizer was applied, as often practiced with farmers. The results showed that it was more productive to grow legume/ roselle crops together as depicted by yield advantages of 41%-55% and 44%-58% for Makurdi and Gombe, respectively. Intercropping depressed N-fixation and grain yields. Sole cowpea fixed the highest amount of N (50.07Kg/ha) and 50.73Kg/ha) for Makurdi and Gombe, respectively, while groundnut intercropped with roselle fixed the lowest amount of N (34.63Kg/ha and 34.97Kg/ha) for Makurdi and Gombe, respectively. The highest grain yields of 143.07Kg/ha and 143.73Kg/ha were obtained from sole cowpea for Makurdi and Gombe, respectively, while the lowest grain yield of 104.44Kg/ha and 104.97Kg/ha were obtained from groundnut intercropped with roselle for Makurdi and Gombe, respectively