Changes in Carbon and Nitrogen Mineralization in Soil Organic Matter Under High CO2 Concentrations
Abstract To investigate the effects of different organic materials on soil organic carbon accumulation and carbon and nitrogen mineralization under different CO2 concentrations, field topsoil was used as the test soil and chicken manure, cow manure, and straw were mixed with soil samples as organic materials. The changes in organic carbon, carbon and nitrogen mineralization, and utilization of carbon sources by soil microorganisms were measured under high CO2 (800–1000 ppm) and low CO2 (400–500 ppm) concentrations. The results showed that adding organic material to soil can accelerate the mineralization of organic carbon and reduce the mineralization of nitrogen. While the addition of chicken manure and cow manure reduced the content of total organic carbon and active organic carbon in soil, straw increased the content of total organic carbon and active organic carbon in soil and reduced carbon utilization by the soil microbial community. Collectively, our findings revealed that, under high CO2 concentrations, adding organic material to soil can accelerate the mineralization of organic carbon and reduce the mineralization of nitrogen.