| No-tillage is one of the important innovations of modern farming technique. Compared with conventional tillage, it has high economic and ecological benefits, time saving ,labour saving and conserve soil and water. In the word, about 30 countries use this technique. The area reaches 98,000,000 hectares. With this technique' popularization and application, peoples' attention on the sustainable effect of this technique increasingly. The research object was based on the no-tillage soil under conditions of paddy-upland rotation. Study on soil fertility factor through investigation and laboratory analysis and evaluate the soil fertility quality by multivariate statistical technique. The results were shown as follows:1. After water-cultivation and dry cultivation, along with the no-tillage years increasing, the content of soil bulk first increase and then decrease and reincrease. The maximum of soil bulk occurred in the year of 7-8, the value were 1.61g/cm~3 and 1.66g/cm~3 spectively. It was significant difference compared with that in the conventional soil. Long-term no-tillage can make the soil compact. Soil pH value in no-tillage soil were lower than that in conventional tillage. Soil pH value was significantly higher than that of conventional tillage at the year of no-tillage 2-3, it were decreased by 0.29, 0.46 spectively. Along with the no-tillage years increasing, the soil values were tended to be stable. No-tillage can make the soil acidizing. It was significant in the initial stage.2. The surface (0-5cm) gathering phenomenon of organic matter, total nitrogen, available nitrogen, available phosphorus, and available potassium was obvious in the no-tillage soil. the contents of organic matter and total nitrogen in the plough layer were higher than that of conventional tillage and decreased significantly in no-tillage 7-8 years. After dry cultivation, the tendency of available nitrogen and available phosphorus were consistent with organic matter and total nitrogen. After water-cultivation, the content of available nitrogen in no-tillage was higher than that of conventional soil, but there was no significant difference among different no-tillage years. Available phosphorus kept stabilization after no-tillage 5-6 years when the content of it reached a maximum, and was significantly higher than that of conventional tillage. The content of available potassium has no significant difference compared with conventional tillage in no-tillage 5-6 year and the highest content occurred in the year of 7-8. The contents of fertility index were higher in the condition of water-cultivation compared with dry cultivation3. On soil layer distribution, there were no rules in the no-tillage, except exchangeable Mg under water-cultivation. In the top soil (0-20cm) the contents of exchangeable Ca and exchangeable Mg in no-tillage soil were lower than that of conventional tillage, along with the no-tillage years, the lowest content occurred in the year of 7-8. Compared with conventional soil, the content of exchangeable Ca decreased by 33.38%, 51.77%, and the content of exchangeable Mg 34.82%, 40.32%, which was significant difference compared with that in the conventional soil. The content of exchangeable Ca was different between paddy-upland and exchangeable Mg has the same phenomenon.4. The surface gathering phenomenon of available Zn was obvious in the no-tillage soil, except available Fe, Mn, and Cu. In the top soil (0-20cm) the content of available Fe, Mn, and Zn under water-cultivation condition and available Mn under dry cultivation condition were higher than conventional tillage in the initial stage of no-tillage. The content of available Fe, Mn, Cu, Zn decreased significantly in no-tillage 7-8 years, along with the no-tillage years increasing. Compared with dry cultivation, the content of soil Available Fe was highly in the condition of water-cultivation. Will, the content of Available Mn, Cu, and Zn shows an opposite result.5. After water-cultivation and dry cultivation, the values of soil integrated fertility index (IFI) decreased significantly in the year of 7-8, and it were 0.269, 0.139, which were lower than that of conventional tillage 0.486, 0.511. It can be known that long-term no-tillage can result in deterioration of soil fertility quality. For surface tillage, the value of soil integrated fertility index significantly increased in no-tillage >10 years.
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