Organic Matter Sources, Soil Fertility and Productivity: Evaluation of Different Sources of Organic Matter on Soil Fertilty and Productivity

Four organic materials namely cow dung, maize stover, M. pruriens vines and L. Leucocephala prunnings along with varying rates of inorganic fertilizer recommendation, were evaluated in the laboratory, the greenhouse and in the field for their impact on soil fertility and productivity in the Nigerian savanna, with maize as the test crop. Based on their nutrient concentrations and deduced ratios, cowdung, M pruriens vines and L. Leucocephala prunnings were characterized as high quality materials. Maize Stover may be considered as a low quality material. Principal component and correlation analysis confirmed this grouping of the organic materials. Applications of the organic materials alone led to 160 to 630% increases in maize grain yield relative to unamended control. The yield increases were in the following order: cow dung> M pruriens vines > L.leucocephala prunnings> maize stove. Combined applications of organic and inorganic fertilizers led to higher values of soil N and P, and better maintained the integrity of soil CEC without a corresponding decline in yield.