A Study on the Net Greenhouse Gas Emissions under Intensive High-yielding Cropland in North China-A Case Study of Winter Wheat-Summer Maize Rotation System in Huantai County

Utilizing the LCA matrix, we preliminarily analyzed whether wheat-maize rotation system was a carbon sink or a source based on long-term and large-scale straw return in Huantai county. The results indicated that the mode was a carbon source if we comprehensively considered agricultural materials production subsystem and farming subsystem together, with the quantity of net GHGs being -1075.71kgCO2e when producing 1 ton of wheat and maize. But if only farming system was considered, the averaged quantity of cropland carbon sequestration was +262.31 kgCO2e, which could offset the -222.99 kgCO2e carbon emission caused by fertilizes and agricultural machine. Therefore, through straw return and tillage system improvement, farming system might become the carbon sink in the future.