Influence of Soil Fertility Management Practices on the Nodule-forming Ability of Some Soybean Varieties in a Sub-humid Environment, Nigeria

Abstract

In a two-year field trials, the influence of eight soil fertility management practices in optimizing the  ability  of six selected promiscuous soybean varieties to form nodules was evaluated in Abakaliki, Southeastern Nigeria which has no history of soybean cultivation in the past. Soil test before planting indicated a pH of 5.50 and 5.85 after harvesting with high available phosphorus, which may have been the reason for its low impact in influencing nodule formation among other practices. Poultry manure and wood ash were both affordable and available low-external inputs which had high potentials in improving and optimizing nodule formation in the soybean varieties to 73.14% and 50.92% in 2008 and 68.55% and 30.77% in 2009, and both are highly recommended as veritable tools for improving soil fertility among the smallholder farmers, where high cost of external inputs has always been the major setback to crop production.

Keywords: Inorganic fertilizer, nodule formation, poultry manure, promiscuous soybean, soil fertility