Abstract:

The study aims to identify the relationship between carbon input and carbon storage/carbon content and yields, and the difference of carbon sequestration efficiency of different fertilization tests under long-term fertilization in red paddy soil. The data of rice yield, soil organic carbon content, soil organic carbon reserves and rice yield under different fertilization for a long time were measured by using the method of continuous monitoring. Results showed that soil organic carbon content of all treatments increased, after 37 years, soil organic carbon content of NPKM was 30.5%, 23.4% and 24.7% higher than that of CK, NPK and NPK2, respectively. The storage of organic carbon increased significantly with the increase of carbon input. The carbon sequestration efficiency of NPK, NPK2 and NPKM treatment was 32.7%, 25.9% and 35.0%, respectively. There was a significantly linear positive correlation between rice yield and soil organic carbon content. Soil carbon content and carbon storage of CK and all fertilization tests were on the rise under double-rice planting mode. Carbon sequestration efficiency was improved significantly when chemical fertilizer was combined with organic fertilizer. There was a significantly positive correlation between organic carbon content and rice yield.

Key words: red paddy soil, organic carbon content, organic carbon stock, carbon input, efficiency of carbon sequestration