Comprehensive evaluation of soil fertility in Liangshan tobacco growing area.

The principal component analysis in the SPSS statistical software was adopted to conduct a comprehensive evaluation of soil fertility according to 9 fertility indicators of 5 soil types in Liangshan tobacco growing areas.The cumulative contribution rate of three main components was 86.96%.The original indicators information could be explained basically by these three main components.The three main components were: ① soil organic matter,organic total carbon,total nitrogen,total phosphorus,available nitrogen,available phosphorus content;② total potassium and available potassium content;③ pH-value.The integrated fertility score of various soil types showed the following order: yellow soil purple soil red soil paddy soil yellow brown soil.