Evaluation of Compost and Biochar to Mitigate Chlorpyrifos Pollution in Soil and Their Effect on Soil Enzyme Dynamics

The widespread environmental contamination of chlorpyrifos (CP) has raised human health concerns and necessitated cost-effective methods for its remediation. The current study evaluated the degradation behavior of CP in compost and biochar amended and unamended (original and sterilized) soils in an incubation trial. Two levels of CP (100 and 200 mg kg−1), compost and biochar (0.50%) were applied, and soil was collected at different time intervals. At the higher CP level (200 mg kg−1), CP a showed lower degradation rate (ƙ = 0.0102 mg kg−1 d−1) compared with a low CP level (ƙ = 0.0173 mg kg−1 d−1). The half-lives of CP were 40 and 68 days for CP at 100 and 200 mg kg−1 in original soil, respectively, and increased to 94 and 141 days in sterilized soils. CP degradation was accelerated in compost amended soils, while suppressed in biochar amended soils. Lower half lives of 20 and 37 days were observed with compost application at CP 100 and 200 mg kg−1 doses, respectively. The activities of soil enzymes were considerably affected by the CP contamination and significantly recovered in compost and biochar amended soils. In conclusion, the application of organic amendments especially compost is an important strategy for the remediation of CP contaminated soil.