[Research Progress on the Effect of Biochar Addition on Soil Microorganisms in Cultived Land]

Biochar is a carbon-rich product derived from the pyrolysis of fibrous biomass. It has attracted considerate attention because of its functions, such as improving soil fertility, achieving soil carbon sequestration, and adsorbing soil pollutants. Soil microorganisms are the main components of the soil life system in cultivated land, playing an important role in soil structure, nutrition, ecological balance, and plant health. Soil microorganisms are involved in the complex relationship between biochar addition and cultivated soil and plants. Therefore, the direct effects of biochar on soil microorganisms and indirect effects on soil properties, plant root growth, and metabolic status were investigated. Biochar could directly provide habitat and nutrients for soil microorganisms, alter enzymatic activity, and affect signal communication. Polycyclic aromatic hydrocarbons （PAHs） and other substances in biochar were not conducive to the survival and metabolism of soil microorganisms. Biochar could indirectly affect soil microorganisms by improving soil physical and chemical properties, such as porosity, pH, aggregate structure, and bulk density, stimulating plant growth, changing secretion status, and enrichment of harmful substances. The observed effects of biochar on the metabolic activities and community structure of soil microorganisms in cultivated land were complex, related to the properties of biochar raw materials, processing technology, and application rate. We proposed biochar products with low preparation cost, few potential hazards, and high comprehensive benefits and prospected future research directions, providing a basis for the study of biochar regulation in cultivated land soil.