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Xinjiang is China's largest production base of high-quality commodity cotton, cotton area in Xinjiang accounted for 40% of the total cultivated area in the main cotton producing areas, the proportion of up to 80% or more, even for very common phenomenon. Long-term continuous cropping of cotton cotton natural resources lead to degradation of the quality, causing serious pest damage, soil nutrient imbalance, the destruction of farmland ecological balance, cotton quality declined, making cotton output and efficiency are affected, the sustainable development of agricultural production and have a very large potential risk. Coupled with long-standing large amounts of fertilizer, pesticides and plastic sheeting applied, making the already fragile ecological environment carrying capacity declining. For continuous cropping soil functional impact is the focus of attention, where research is more soil enzymes. Select the lake basin, Toto Township cotton as research object, even for five years, 10 years, 15 years, 20 years, 30 years, cotton soil enzyme activity and soil physical and chemical properties of the situation, as well as the correlation between the two. Aims to investigate the cotton cropping effects on soil micro-environment in order to reveal the characteristics of soil quality cotton, cotton in Xinjiang to provide the basis for sustainable development. The main results are as follows: (a) cotton, natural and semi-natural sample plots activity changes of soil characteristics: catalase, phosphatase, urease and invertase in 0 5 0cm activity within trends for the cotton gt; semi-natural plot gt; natural plot; vertical direction overall performance for the upper gt; middle gt; lower, ie decreasing with soil depth. (2) cotton, natural and semi-natural plot plots the variation of physical and chemical properties as: soil moisture, organic matter are manifested as cotton gt; semi-natural plot gt; natural plot, the vertical depth of soil moisture with the increase of cotton fields and semi-natural organic matter content expressed as plots with depth diminishes; total salt content were natural plot gt; semi-natural plot gt; cotton, natural and semi-natural plots plots attributed to extreme heavy salinized, cotton is moderate salinization; every soil pH of 8.0 or more, the natural and semi-natural plots plots belong to the strongly alkaline soil, cotton is an alkaline soil; ion content of each soil profile by the the lower to the upper gradually increased ion content in general is: SO 4 2 - gt; Ca 2 gt; Cl - - gt; Mg 2 gt; HCO 3 - gt; CO 3 2 - < / sup>. The study area is mainly sulfate salts, salt ions accumulate mainly in migration trends, there is little leaching desalination process, soluble salts upstream process, sulfate accumulation at the most intense. (3) Different Cropping Cotton Soil enzyme activities characterized by: at 0 5 0cm inside, with the increase of years of continuous cropping, soil catalase activity expressed as 30 years gt; 10 years gt; 20 years gt; 15 years gt; 5 years, in the section decreased with soil depth; urease activity trends for the 20-year gt; 10 years gt; 30 years gt; 15 years gt; 5 years, from 5 to 30 years, the overall performance is increased; invertase activity trends in the performance of 30-year gt; 20 years gt; 10 years gt; 5 years gt; 15 years of continuous cropping of 10 years invertase activity showed middle gt; Upper gt ; the lower layer, the remaining Cropping showed an increase with soil depth decreases; phosphatase activity expressed as the mean of 20 years gt; 10 years gt; 5 years gt; 30 years gt; 15 years. 5 years, 15 years, 20 years, 30 years of phosphatase activity showed an upper gt; middle gt; lower; cropping period of 10 years invertase activity showed middle gt; Upper gt; basement. (4) Different Cropping Cotton Soil enzyme correlation between are: phosphatase and invertase, urease in a very remarkable and significant levels were positively correlated catalase and urease, invertase in a very remarkable and significant levels were positively correlated with sucrose enzyme urease correlation was not significant. (5) Different Cropping Cotton variation of soil properties: In 0 5 0cm inside, with the increase of years of continuous cropping, soil moisture trends of 10 years gt; 5 years gt; 20 years gt; 30 years gt; 15 years, the performance of the soil profile with soil depth increases; total salt showed an increase with continuous cropping declining, which is 5 years gt; 10 years gt; 20 years gt; 15 Year gt; 30 years, even for five years and 10 years are very severe salinization, even for 15 and 20 years are heavy salinized, even for 30 years, is moderately salt; pH trends 15 years gt; 5 years gt ; 10 gt; 20 years gt; 30 years; from cropping five to 30 years between organic matter content of the overall trend is increased, that is, 10 years gt; 20 years gt; 30 years gt; 5 years gt; 15 years in the soil have shown cross section gradually decreasing from top to bottom; soil CO32-ions in addition, the change trend of continuous cropping with the increase of decreasing ion content of the overall performance of SO 4 2 - gt; Ca 2 gt; Mg 2 gt; Cl - gt; HCO 3 - gt; CO 3 2 - . (6) canonical correlation analysis, Pearson correlation analysis and stepwise regression analysis showed that, from the point of view into the soil physical and chemical factors, organic matter is a better indicator of predictive activity can be used to predict the level of enzyme activity. (7) Continuous Cropping Cotton Soil salinization comprehensive evaluation showed, 0 5 0cm soil ranked composite score of five years gt; 20 years gt; 10 years gt; 15 years gt; 30 years . It can be concluded, with the extension of continuous cropping, soil salinization degree of harm is greatly improved.
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