论文部分内容阅读
应用甘肃农业大学定西旱农综合试验站的2001—2008年长期定位实验数据对DNDC模型进行验证,4个处理的相对误差均小于±10%,均方根误差在6.41%~12.96%之间,模型模拟值与实测值表现出较强的一致性,证明DNDC在模拟预测该地区土壤有机碳储量上是可行的。对定位试验的4个处理的长期(100 a)模拟表明,免耕覆盖秸秆(NTS)和传统耕作+秸秆还田(TS)能够较大幅度地提高土壤有机碳含量,其土壤有机碳含量分别较初始值增加了74.76%和71.13%,免耕(NT)处理下土壤有机碳含量增加了39.18%,趋势较为平缓。而传统耕作不覆盖(T)处理下土壤有机碳呈下降趋势,较初始值减少了35.54%。土壤有机碳含量对土壤性状以及耕作管理措施变化的响应模拟研究表明,秸秆还田和施用有机肥是最有效的提高土壤有机碳含量的耕作措施,而土壤性状,尤其是初始有机碳含量是影响土壤有机碳变化的最主要敏感因素。DNDC模型模拟得出,实行秸秆覆盖或还田及免耕等耕作措施将有效持续地增加土壤有机碳含量,提高土壤的可持续利用能力。
The DNDC model was validated by long-term positioning experimental data from 2001 to 2008 of Dinghan dry-farming comprehensive experimental station of Gansu Agricultural University. The relative errors of the four treatments were less than ± 10% and the root-mean-square error was between 6.41% and 12.96% The simulated values of the model and the measured values show a strong consistency, which proves that DNDC is feasible in predicting soil organic carbon storage in the area. The long-term (100 a) simulations of the four treatments of the location experiment showed that no-tillage covered straw (NTS) and traditional tillage + straw returned to the field (TS) increased soil organic carbon content significantly, and soil organic carbon content Compared with the initial value, the content of soil organic carbon increased by 74.76% and 71.13%, and the soil organic carbon content increased by 39.18% under no-tillage (NT). However, the soil organic carbon in the non-coverage (T) treatments showed a decreasing trend, decreasing by 35.54% compared with the initial values. Response of soil organic carbon content to changes in soil properties and tillage management practices Simulation studies show that straw and organic manure are the most effective tillage measures to increase soil organic carbon content, while soil properties, especially initial organic carbon content, are affected The main sensitive factors of soil organic carbon change. DNDC model simulation shows that the implementation of tillage or straw mulching and tillage and other tillage measures will effectively and continuously increase the content of soil organic carbon and improve the sustainable utilization of soil.