ABSTRACT
This experiment was conducted to investigate the effects of poultry manure application on some chemical properties of soil and the availability of certain macronutrients in depleted soils at the University of Benin Research Farm, Ugbowo, Edo State, Nigeria. Poultry manure was selected for this study as an effective fertilizer. This research involved the application of varying rates of poultry manure specifically 0 kg, 5 kg, 10 kg, 15 kg, and 20 kg per hectare across designated plots to assess their effects on soil pH, total organic carbon (TOC), and essential macronutrients, including nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), sodium (Na), and sulfur (S). The results indicated that soil pH ranged from 4.97 to 6.15, with the highest pH observed at 15 kg/ha of manure. TOC levels were significantly enhanced at the 5% level of significance (p<0.05) with values of 7.6 g/kg in the control group and up to 13.5 g/kg in the 10 kg/ha treatment. Nitrogen content peaked at 0.7 g/kg with the 10 kg/ha application, while phosphorus availability reached 9.15 g/kg at the same rate. Potassium levels were highest at 0.85 cmol/kg with 15 kg/ha, and magnesium concentrations varied, with the 10 kg/ha treatment yielding 0.99 cmol/kg. Sodium levels increased to 0.18 cmol/kg at 15 kg/ha, and sulfur content was highest at 11.3 g/kg with 10 kg/ha. Although poultry manure application had minimal impact on soil texture, it slightly influenced clay content, particularly in the 10 kg/ha treatment, which shifted the soil classification from sand to loamy sand. These show the importance of managing poultry manure effectively as a sustainable soil amendment to combat soil depletion and promote healthier agricultural systems for ultimately contributing to improved crop yields and soil health.
