Growth and Yield of Bambara groundnut (Vigna Subterranean) in a Soil Amended with Different Rates of Pig and Cow Manure in Humid Tropical Region of Nigeria

Organic manure is crucial for enhancing soil fertility and promoting plant growth, particularly in nutrient-deficient soils. This study was conducted at the Teaching and Research Farm of the Crop Science and Horticulture Department, Nnamdi Azikiwe University, Ifite-Ogwari Campus, Anambra State, to evaluate the effects of different types and rates of organic manure on the growth and yield of Bambara groundnut (Vigna subterranea). The experiment employed a completely randomized design (CRD) with treatments consisting of various manure applications: pig manure (PM) at rates of 5t/h, 10t/h, and 15t/h, cow manure (CM) at equivalent rates, and a control (no manure applied), replicated three times. Results revealed that pig manure at 10t/h significantly enhanced the leaf area and branches per plant, with means of 269.0 (cm²) and 89.7 respectively recorded at 12 weeks after sowing (WAS). Furthermore, cow manure at 15t/h showed comparable effects, particularly on leaf area and stem girth, indicating its potential for improving growth metrics. The interaction of pig and cow manure also positively influenced all growth parameters measured at 12 WAS, with notable increases in leaf area (254.9 cm²) and plant height (27.8 cm). Overall, pig manure demonstrated superior efficacy in boosting pod and seed yields, with recorded values of 510 g/plant and 195 g/plant respectively at the highest application rate. The findings suggest that integrating organic manure, particularly pig manure, is effective for optimizing growth and yield in Bambara groundnut cultivation, thereby promoting sustainable agricultural practices in similar agro-ecological zones.