Impact of Organo Minerals and Their Integrated Forms on Soil Fertility and Maize Productivity in Southeastern Nigeria

Agricultural soil quality is drastically affected by modern human activities. This study evaluates sole and combined effect of three agro-wastes namely: - rice husk Ash (RHA), rice husk dust (RHD) and poultry manure (PD) on soil fertility nutrient content and grain yield of maize on an Ultisol in Southeast Nigeria. Single and combined effects of the materials were investigated at application rates of 10t/ha for sole PD and RHD, 5 t/ha for sole RHA, 5 t/ha PD + 5 t/ha RHD, 5 t/ha PD + 2.5 t/ha RHA and 3.33 t/ha PD + 3.33 t/ha RHD + 1.67 t/ha RHA with 0 t/ha(control) giving seven treatments. The soil studied was low in pH, organic carbon (OC), total nitrogen, available phosphorous, exchangeable potassium and cation exchange capacity. The soil parameters studied include soil pH, OC, Total nitrogen, exchangeable bases, CEC, EA and available phosphorous while the grain yield of maize was also measured after harvest. Results showed that the amendments significantly improved the soil pH, organic carbon, exchangeable Na, K, Ca and Mg, while the total nitrogen was not affected significantly. Exchangeable acidity was drastically reduced by the amendments, while the available phosphorous was significantly increased by the application of treatments. Maize grain yield was also significantly increased by the treatments applications. The integrated application especially at 5 t ha-1 poultry manure and 5 t ha-1 rice husk dust increased maize yield and most soil nutrient elements higher than other combinations in the study.