四川盆地秸秆还田免耕对土壤养分及碳库的影响

Effects of straw-mulching and no-tillage on soil nutrients and carbon pool in Sichuan Basin

在四川盆地2种不同母质的土壤上,通过3 a 6季作物的田间试验,研究作物秸秆还田对稻田土壤N、P、K,土壤活性碳,微生物碳,矿化碳和碳库管理指数的影响.结果表明:与对照相比,秸秆还田免耕和旋耕均可提高土壤全N,全P,全K,有效N、P、K,不同形态碳素含量和碳库管理指数.作物秸秆还田旋耕比秸秆还田免耕更能改善土壤有效碳库质量,土壤活性碳、微生物碳、矿化碳和碳库管理指数分别提高5.81%～31.76%、33.87～39.33%、15.42%～21.56%和4.03%～21.13%.相关性分析表明,运用土壤碳库管理指数表征土壤养份及碳素动态变化比土壤有机碳更具灵敏性.

The content of NPK,different available carbons and CPMI are discussed through a fixed field experiment of three years on two kinds of different parent materials soil in Sichuan Basin.The results indicated that straw-mulching treatment increased the content of soil organic matter,total NPK,available NPK,different available carbons and CPMI.Treatment of straw-mulching-spiral-tillage can improve the quality of available carbon cool comparing with straw-mulching-no-tillage,and CA、CMB、CM and CPMI increased 5.81%-31.76%,33.87%-39.33%,15.42%-21.56% and 4.03%-21.13% respectively.The results of correlation analysis demonstrated that CPMI can reflect the dramatic variation of soil fertility and soil carbon more actively than that of soil organic matter.