| The long-term located experiment has been conducted on the grey desert soil in the Fukang Desert- Ecology Station in Xinjiang since 1991 with the purpose to investigate the dynamic changes of 15 indicators of soil quality. The results showed that there were great differences of physical and chemical characters among different treatments. Through principal components analysis, three factors were determined for 88.9% of the variance interpretation. The 15 evaluation indicators could be divided into 3 principal components: the first was organic matter mineralization factor which had a positive loading on nutrition level, enzyme activity and crop yield; the second was soil potassium factor which had a positive loading on total K, available K, CEC and urease activity; the third was soil phosphorus factor which had a positive loading on total P and available P. According to the comprehensive factor scores, the effect of combination application of organic manure and chemical fertilizers were superior to single chemical fertilizers in improving the activities of soil enzyme and nutrients. |