Innovative approaches: Exploring nano-biochar technology’s impact on soil properties, alachlor retention, and microbial populations

Abstract

Pesticide contamination and soil degradation stand as critical challenges in the agricultural ecosystem. This study delves into the impact of nano-biochar (NBC) on soil properties, alachlor retention, and microbial populations, exploring concentrations of 1 %, 3 %, and 5 % w w−1 in both planted and unplanted alachlor-contaminated soil. A six-week black bean-pot experiment was conducted in planted soil. The NBC, distinguished by its substantial carbon content and remarkable surface area, pore volume, and diameter, resulted in significant enhancements in soil pH, moisture content (MC), and soil organic carbon (SOC). Over the 6-week period, NBC3% and NBC1 % consistently increased SOC content, while NBC5% displayed a declining trend after the 4th week. The application of NBC led to a remarkable acceleration in alachlor reduction, achieving efficiencies exceeding 77 % in unplanted soils and reaching an impressive 97.3 % in planted soils. The reduction dynamics, modeled by a first-order equation, revealed notably shorter half-lives of alachlor in NBC-treated soils compared to controls. Abundance in total plate count (TPC), phosphate-solubilizing bacteria (PSB), and nitrogen-fixing bacteria (NFB) increased with NBC1 % and NBC3 %, although NBC5 % showed a decline after the 2nd week. The findings suggest that NBC1 % and NBC3 % offer optimal outcomes for desired soil improvements, enhanced microbial activity, and effective soil pesticide removal.