Carbon-Mediated Responses of Soil Nematode Communities to Miscanthus-Derived Biochar in a Controlled Sweet Corn Pot Experiment

The purpose of this study was to evaluate early chemical and biological responses of soil to miscan-thus-derived biochar in a controlled pot system with sweet corn. A short-term pot experiment was conducted using natural soil amended with miscanthus-derived biochar at different rates. Sweet corn was grown under controlled conditions, and soil samples were collected at the start of the experiment and after 60 days in both the with and without plants treatments. Biochar application increased total organic carbon content and modified several soil chemical properties, including nutrient availability, oxidation-reduction potential, and electrical conductivity. Total nematode abundance increased by up to 90% in biochar-amended soils compared with the control, with the strongest response observed in bacterivorous nematodes, indicating stimulation of bacterial energy channels. Multivariate analysis confirmed that soil carbon status and nitrogen availability were the main factors structuring nematode community composition. Overall, these findings show that short-term biochar amendment primarily enhances bacterial-driven soil processes, supporting the use of nematode functional indicators for early assessment of soil response in horticultural systems.