Soil Chemical Properties and Interactive Effect of Livestock Manure and Variety on Growth, Yield, Seed Nutritional and Proximate Compositions of Groundnut (Arachis hypogaea L.)

Unavailability and escalating cost of fertilizer coupled with the need to safeguard the environment has called for the use of local nutrient resources for soil fertility management. A pot experiment was carried out to investigate the effect of manure from different livestock dungs on soil chemical properties as well as the interaction effect of variety and manures on growth, yield, as well as seed nutritional and proximate composition of tah-erect and tah-creeping varieties of groundnut (Arachis hypogaea L.). Plants were grown in soil amended with poultry dung (PD), cow dung (CD) and goat dung (GD) while the treatment with no dung (ND) served as the control. The experiment was laid out in complete randomized design with 5 single plant replicates per treatment. Results showed that livestock manure generally enhanced the nutrient content of the soil compared to the control. Soil amended with PD contained the highest N, P. K, Ca, Mg and Na followed by CD, and then GD. Organic content was highest under CD followed by GD and least in PD. Heavy metals including Fe, Mn, Cu and Zn were higher under CD than in GD and PD. There was a significant difference (p<0.05) in number of leaves, number of branches, shoot length and stem girth among the treatments in both varieties, where PD followed by CD displayed superiority over GD, which was however better than the control. PD led to the highest number of seeds, seed fresh and dry weights in both varieties as compared to CD and GD, which were better than the ND where the least values were recorded. Seed N, P, K, Mg and Ca were increased in both varieties by livestock manure applications. Except the carbohydrate content that was unaffected, proximate parameters including protein, fat, crude fibre, percentage ash and moisture content in the seeds of the two varieties were higher in plants grown in manure-treated soil than in the control. Livestock manure enhanced availability of nutrients in soil for increased vegetative growth and seed yield, as well as seed nutritional and proximate values in the two varieties of Arachis hypogaea.