The Characters And Changes Of Available Soil Nutrients Of Hotan Oasis

Soil is an important natural resources and indispensable environmental condition to the survival of human. With the development of science, soil science an important natural basic disciplines has been continuously in-depth research and development. Soil is a part of the surface soil which is the basis of material life of vegetation. The content of available soil nutrients is an important indicator in measuring soil fertility. Therefore the study of available soil nutrients is of great significance to guiding agricultural production and soil improvement.659 samples were collected in Hotan Oasis of Xinjiang. There are 17 soil profiles, by every 10 cm from a sample, collected a total of 250 soil samples which includes 7 in oasis zone, 6 in the transitional zone and 4 in desert zone. 409 surface soil samples were collected in different landscape.All soil samples have been measured in the laboratory. In this paper the statistical methods and SPASS statistical software (13.0) were used. The analysis was combined with Hotan soil survey information in 1980s.The results show that the content of available soil nutrients in the study area is a medium-intensity variation. With the increase in depth, the contents of available soil nutrient in different landscape show an Downward trend. The increase of available soil nutrient contents is concentrated in the surface soil.The contents of available N is 26.17 mg/kg -57.5 mg/kg. The contents of available P is 12.87 mg/kg -16.70 mg/kg. The contents of available K is 982.06mg/kg-999.41mg/kg .Oasis with the contents of available soil nutrient is the largest in the three landscape zone. The contents of available N ,available P, available K and soil organic matter have a very significant positive correlation, the correlation coefficient is 0.590**,0.200*,0.311**. Serious imbalance is in the proportion of nitrogen and phosphorus. The proportion in oasis zone is 5.25, it in transitional zone and desert zone is 3.65 and 1.74. For phosphorus is very low intensity, it in oasis zone, transitional zone and desert zone is 0.67%, 1.09%,1.74%;In the past 20 years, Nitrogen strength has improved and the soil available nutrient content of Hotan Oasis upward trend. Among them, soil available K content has increased, but the level is higher, soil available P content has increased from low level to middle class, In Hotan and Luopu County, the available soil N content were rising to a higher level from a very low level. However, the majority samples of Moyu County still belong to a very low level. Three counties should be based on their own soil nutrients and soil conditions improve the soil.