秸秆还田对江西农田土壤固碳影响的模拟分析

秸秆还田等农田管理措施能有效地增加土壤碳储量,从而有利于减缓大气CO₂浓度的上升趋势。论文基于环境政策综合气候模型(EPIC),采用千烟洲生态试验站和鹰潭生态试验站农田监测场长期观测数据,验证和优化了EPIC模型参数,同时利用1990-2010年江西省气象资料以及土壤清查资料,模拟分析了4种秸秆还田(CR)比例情景下2010-2030年江西省水稻田土壤的固碳潜力。研究结果表明,无秸秆还田 (CR0%)和秸秆还田25%(CR25%)两种处理下耕作层土壤有机碳储量分别下降21.3%和6.5%,秸秆还田50%(CR50%)和100%(CR100%)处理下土壤有机碳储量分别增加5.4%和11.9%;相对CR0%情景而言,CR25%、CR50%、CR100% 情景下江西省水稻田土壤总固碳潜力分别为6.43、14.92和25.26 TgC(1 Tg = 10⁶ t)。研究结果表明,通过合理的调控措施,采用保护性耕作(秸秆还田)是提高水稻田土壤固碳能力的一种有效途径。

Simulation and Prediction of Straw Return on Soil Carbon Sequestration Potential of Cropland in Jiangxi Province

Straw return and other farming management measures can effectively increase soil organic carbon (SOC) storage, thus contributing to mitigate the increase in the atmospheric CO₂ concentration. Based on the EPIC model, which was validated using the database of long-term observation in Qianyanzhou and Yingtan experimental stations in Jiangxi Province. EPIC model was based on the meteorological information from 1990 to 2010 and soil database in Jiangxi Province, to simulate the paddy soil carbon sequestration potential from 2010 to 2030 under alternative crop residue return scenarios in Jiangxi Province. The results indicated that the top soil organic carbon stocks showed a decreasing trend under the straw removal(CR 0%) and straw incorporation 25% (CR 25%) scenarios, the ratio of loss is 21.3% and 6.5%, and an increasing trend in the case of straw incorporation 50%(CR 50%)and straw incorporation 100% (CR 100%)scenarios, the ratio of increasing is 5.4% and 11.9%;compare to the CR 0% scenario, the carbon sequestration potential of crop straw return scenarios of CR 25%, CR 50% and CR 100% are 6.43, 14.92 and 25.26 Tg C (1 Tg= 10⁶ t) in paddy soils of Jiangxi Province. The simulating results demonstrated that conservation tillage (straw return) is an effective way to improve the paddy soil carbon sequestration.