EFFECTS OF INTERCROPPED LEERSIA HEXANDRA AND CARBON SOURCE AMENDMENT ON NUTRIENT AND MICROBIAL CHARACTERISTICS IN CHROMIUM POLLUTED SOIL

To explore the safe utilization of Cr-contaminated soil, in a pot experiment, the impacts of applying carbon source amendments, sole cropping of Leersia hexandra , and combined treatments on soil mechanical composition, nutrient content, enzyme activity, and microbial quantity were investigated. The results revealed that compared to the control, all treatments were able to alter the mechanical composition of Cr-contaminated soil, organic matter, and the content of available nitrogen, phosphorus, and potassium in soil. They also increased the activities of urease, phosphatase, hydrogen peroxidase, and sucrase enzymes, as well as the populations of bacteria, actinomycetes, and fungi. Among the treatments, those with the most significant effects on increasing available potassium content and soil fungi quantity were BS (biochar + sugarcane bagasse) and BSL (biochar + intercropping + sugarcane bagasse), while BL (biochar + intercropping) had the most significant impact on all parameters compared to their respective sole treatments, demonstrating a pronounced synergistic effect. The combination of biochar and intercropping with hyperaccumulating plants can effectively leverage the advantages of amendments and intercropping in improving the nutrient status of polluted soil, thus providing valuable insights for the safe utilization of Cr-contaminated soil.