Long-Term Tillage and Crop Rotation Impacts on Accumulation and Distribution of Carbon and Nitrogen in Corn and Soil Profile.

In order to evaluate the impact of tillage and crop rotation on accumulation and distribution of carbon (C) and nitrogen (N) in corn (Zea mays L.) and soil profile, we analyzed biomass C and N content in plant tissues and grain of corn at harvests and in soil profile after long-term (50 yr) of continuous tillage and crop rotation management at two experimental sites. The tillage management included no-tillage (NT) and chisel-tillage (CT), and crop rotation included continuous corn (CC) and soybean after corn (SC). The results show that total aboveground biomass C and N accumulation in corn is greater under SC than under CC. Soil C concentration at top soil (0-20 cm) is higher under NT than under CT. This study indicates that application of SC and NT can effectively accumulate C and N in corn and topsoil.