Prasanna et al. Conducted field experiments to study the colonization of cyanobacteria and their effects on soil microorganisms and crop plant parameters. The results showed that inoculation of nitrogen-fixing cyanobacteria under the conditions of applying total phosphorus and potassium and reducing chemical nitrogen fertilizer by 25% still promoted plant growth , Improve crop yield and significantly enhance soil microbial activity. It shows that nitrogen-fixing cyanobacteria not only secrete substances that promote plant growth and affect plant productivity and soil fertility, but also can serve as an organic input source in rice-wheat farming systems by providing nitrogen and carbon.