Effects of soil biofilm on the functions of paddy rice field system

Soil microorganisms can form biofilms through the extracellular matrix secreted by their own cells. The formation of biofilm is conducive to the better adaptation of microorganisms to the surrounding environment, and also plays a certain role in regulating the development of soil and the growth of plants. Soil biofilms can regulate soil element cycling and influence soil pollutant degradation through extracellular polymers and their own metabolic processes. Meanwhile, soil biofilms also play an important role in enhancing rhizosphere immunity, inhibiting pathogen invasion to plant roots, and improving soil fertility and crop yield. Paddy field is the largest constructed wetland in the world. The ecological environment of paddy field can not only satisfy the growth of rice, but also provide excellent conditions for the survival, reproduction and formation of biofilms of soil microorganisms. Various diseases, insect pests, nutrient limitation or heavy metal stress often affect its rice growth and grain yield. Therefore, from the perspective of ecological environment protection, this paper mainly reviews the effects of biofilm on soil heavy metal pollution, nutrient loss and rice growth and health in rice field system.