Varietal Trials Of Soybean And Their Contribution To Soil Nitrogen

Abstract

Two sets of soybean varieties, ten early maturity variety (EMV) and six medium maturity variety (MMV) bred for the Rain Forest Zone of Nigeria, were assessed for seed yield and potentials for increasing soil nitrogen during the late planting season in Calabar, Nigeria. These were laid out in a randomized complete block design with three replications each. No mineral fertilizers were applied. In the EMV, TGX 1805-17F and TGX 1808-2E had significant grain yield over the other variety while TGX 1808-2E proved a better variety in terms of total nodule, viable nodule, yield and accumulated N in soil after harvest. For the MMV, TGX 1807-19E proved the best adaptable variety over others. Correlation analysis of viable nodule number and N grains showed a positive and highly significant relationship for EMV and positive but a non-significant relationship for MMV, suggesting that the soil N gains were obtained through N fixation by these legumes. These varieties have great potential for possible incorporation into our multiple cropping systems to increase soil N.Journal of Applied Chemistry and Agricultural Research Vol. 3 1996: pp. 25-31