Evaluation on the Effects of Organic Amendment on Soil Productivity of Selected Watersheds in Nnamdi Azikiwe University Awka Campus, Nigeria

This study was done to investigate soil physicochemical properties on the prevalence of biodiversity at Nnamdi Azikiwe University Awka and Amansea and to compare the performance of the different study areas (abandoned farmland and heavily grazed land) with respect to their productivity using different soil amendments. A soil amendment experiment was carried out using CRBD with four treatment levels of poultry manure for abandoned farmland and heavily grazed land. The study results revealed that soil physicochemical properties vary significantly across the study area. The difference between nitrogen and potassium levels were found to be significant at (P < 0.05), indicating favourable conditions for plant growth in specific locations. Conversely, other parameters, such as moisture content, phosphorus, organic matter, and pH, were not significant at (P > 0.05), suggesting suboptimal conditions for certain plant species. Roadside ecosystems exhibited the highest soil chemical properties, particularly potassium, making them conducive for plant growth. The perennial watershed ecosystem also offered favourable conditions, fostering a variety of plant species. In contrast, annual watershed areas exhibit the least soil nutrient support due to potential leaching effects. There was a notable positive correlation was observed between soil moisture and soil pH, percentage nitrogen, phosphorus, and potassium content (p<0.05). Specifically, significant positive correlations were identified between soil pH and phosphorus, as well as between soil pH and potassium (p < 0.05).More so, analysis of variance showed a significant difference between sites in all the physiochemical parameters examined (p<00.05).