ABSTRACT
This experiment was conducted to investigate the effects of pig manure application on some chemical properties of soil and the availability of certain micronutrients in depleted soils at the University of Benin Research Farm, located in Edo State, Nigeria. Pig manure was obtained from the university farm for the study. “This research involved the application of varying rates of pig manure at 0 kg, 5 kg, 10 kg, 15 kg, and 20 kg per hectare to investigate parameters, such as soil pH, total organic carbon (TOC), and the availability of essential micronutrients such as copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn)”. The results of the study revealed that soil pH values ranged from 5.03 to 5.69, indicating varying levels of acidity across the different treatment plots. Notably, the highest concentration of total organic carbon (19.9 g/kg) was recorded in the plots that received the 20 kg application rate of pig manure. Also, the application of 5 kg of pig manure significantly increased the levels of copper (0.83 mg/kg) and iron (11.7 mg/kg) in the soil. In contrast, higher application rates of 10 kg and above resulted in nutrient dilution, which adversely affected the availability of specific micronutrients. The particle size distribution analysis confirmed that the sandy texture of the soil remained largely unchanged, with sand content consistently ranging from 90.43% to 91.93% across all treatments. This finding suggests that while pig manure can enhance soil fertility and nutrient dynamics, it does not significantly alter the inherent textural characteristics of sandy soils. This study shows the potential of pig manure as a sustainable organic amendment to restore soil fertility and improve micronutrient dynamics, emphasizing the need for careful management of application rates to prevent nutrient imbalances and ensure long-term soil health
