Research On Soil Quality In Yutian Oasis Of The Keriya Valley

Soil is a basic resource for human beings, its quality directly affect the human production,life and development. Soil quality is to seek a balance and the overall performance betweenthe different soil functions to determine the intrinsic properties of the soil, and it must becomprehensive expressed according to the external properties of soil that we have mastered.With the intensified pressure of population increasing on the natural resources and theenvironment, and the soil quality decline caused by sanitization of soil, soil fertility decline,and desertification limited the progress and development of human society very seriously. Byanalyzing soil water-salt, nutrients and enzyme activity, this study made an attempt to discussthe relationships between soil nutrients, enzyme activity and water-salt properties by themethods of path analysis in Keriya Oasis. While revealing the physical and chemicalproperties of soil, enzyme activity response to soil water and salt factors through constrainedordination methods. And then by building soil quality evaluation system and thecorresponding evaluation index, use the factor analysis and cluster analysis to evaluate soilquality status under different land use types in Keriya Oasis. In order to provide a reference tothe improvement of soil quality, agricultural lang planning, and the development andutilization of soil resources in the oasis.1. The study on soil water-salt, nutrients, enzyme activity properties in oasis showed thatthe soil enzyme activities, soil moisture and nutrients were relatively low while the soilsalinity and alkalization were generally high; meanwhile, the range of groundwater depth wasbig.2. There were significant differences among different soil types in terms of soilwater-salt, nutrients and enzyme properties in Keriya Oasis. The soil moisture of farmlandwas the highest, the groundwater depth of saline-alkali wasteland was the lowest and sandyland was the highest, pH and soil total salt in aline-alkali wasteland were high; Soil organicmatter, total nitrogen and available P of farmland were highest, available K of saline-alkali wasteland was the highest and farmland was the lowest and it different from others; Theenzyme activity of farmland was the best.3. The path analysis and the redundancy analysis showed the relationship between soilnutrients, enzyme activity and water-salt. The soil nutrients and enzyme activity were largelydetermined by soil moisture and groundwater depth, soil moisture and nutrients(exceptavailable P, available K) had positive relationships while groundwater depth had significantnegative relationship; Available P had no significant effect; The available K was determinedlargely by salt factors though the direct path coefficients to water properties were bigger.4. Construct soil quality indicators to evaluate the soil quality. The results of soil qualityevaluation in different land use types was in the order of farmland＞forest land＞grassland＞Saline-alkali land＞sandy land. By clustering analysis to classified the soil quality grades ondifferent soil types: farmland was classified into grade1, forest land and grassland soil qualitygrade was2, soil quality in saline-alkali land was close to grade3, and sandy land had a soilquality of grade4.