Application of Biochar for the Reduction of the Effects Generated by Microplastics in Agricultural Soils: Case Study in Carabayllo, Lima

Abstract

Abstract– Microplastic contamination in agricultural soils represents an emerging threat to soil productivity and quality. In the Carabayllo district, where agriculture supplies 45% of the horticultural production for Metropolitan Lima, the accumulation of microplastics in the soil is a source of environmental concern. This study evaluated the effectiveness of biochar in reducing the negative effects of microplastics in agricultural soil in the Chocas Bajo sector of Carabayllo. The design of the investigation was quantitative exploratory-correlational with soil sampling at nine points to quantify microplastics through digestion with H2O2 and separation by density with NaCl. Subsequently, biochar doses of 0%, 1%, 2%, and 5% of the soil weight were applied in a pot experiment. Soil chemical properties (pH and electrical conductivity) and growth variables of the selected crop (shoot length, root length, and fresh biomass) were analyzed. The results showed an average concentration of 95.9 ± 57.1 microplastic particles per kilogram in the soil. Application of biochar regulated the pH towards neutral values and showed a significant positive correlation with electrical conductivity and with growth variables, with the 2% dose standing out for its best performance.