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

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.