Effect of Chinese milk vetch (astragalus sinicus l.) and rice straw incorporated in paddy soil on greenhouse gas emission and soil properties

Abstract

Paddy soil is an important emission source of agricultural greenhouse gases. The excessive application of chemical fertilizer to paddy soil is one of the important reasons for high greenhouse gas emissions. Emissions can be reduced through optimized agricultural management measures. The incorporation of Chinese milk vetch (CMV) and rice straw in the field to replace some of the chemical fertilizer can reduce the emissions of greenhouse gases, but the relationship between these emissions and soil properties after the incorporation of CMV and rice straw is unclear. Through the continuous determination of greenhouse gases and the physical and chemical properties of soil, it was found that the addition of CMV and straw could increase the emissions of methane (CH4) and carbon dioxide (CO2), but nitrous oxide (N2O) emissions were lower. The effect of the combined incorporating of CMV and rice straw on soil properties was more significant than CMV alone. It was also found that CH4 and CO2 emissions were positively correlated with microbial biomass carbon and nitrogen, pH, and soil catalase and β-xylosidase activities. In practice, we can reduce greenhouse gas emissions by water and fertilizer management.