Although carbon, nitrogen, and phosphorus, etc. are essential elements for agricultural production, they cause various environmental issues, such as groundwater contamination by nitrate nitrogen, eutrophication of water area by nutrient salts and global warming due to carbon dioxide, nitrous oxide and methane gas. These elements are circulating in ecosystems in various chemical forms. Microorganisms are the important drivers in these processes. The expansion of human activities has affected these biogeochemical cycles and the impact extends from a familiar ecosystem to the global scale now.
Aiming to optimize these cycles, we elucidate the effects of changes in agricultural management practices and applied materials on soil and water quality. We also evaluate the nitrogen and other nutrient cycles at the regional and national scales. In addition, we elucidate the function of organisms to drive carbon and nutrient cycles while proposing technologies for improving cyclical function of nature using organisms living in the agro-environment.