SOIL ENZYME ACTIVITY IN A LEAD CONTAMINATED SOIL AMENDED WITH POULTRY MANURE AND BIOAUGMENTATION

Lead (Pb) contamination in soil poses a serious threat to ecosystem functions due to its toxicity, persistence, and potential for bioaccumulation. Organic amendments such as poultry manure (PM), combined with bioaugmentation, might mitigate these impacts by improving soil microbial activity and enzyme functions. This study evaluated the effects of PM and bacterial inoculation applied over 60 days (every 15 days, four applications) on soil β-glucosidase and fluorescein diacetate (FDA) hydrolysis activities under Pb stress. Results showed that PM alone (PM/Bac–) and in combination with bioaugmentation (PM/Bac+) significantly increased FDA hydrolysis (by 75%) and β-glucosidase activity (by 302%) compared to the control. PM/Bac+ outperformed PM/Bac–, showing 18% higher FDA hydrolysis and 152% higher β-glucosidase activity. These improvements were attributed to enhanced nutrient availability, improved soil conditions, and stimulation of beneficial microbial communities. Overall, the combination of poultry manure and bacterial inoculation demonstrated a synergistic effect, effectively restoring soil biological quality and providing a promising strategy to alleviate the adverse impacts of Pb contamination on soil health and microbial function.