Study On The Characteristics Of Farmland’s Soil Salt In Turpan City

Soil salinization problems have been seriously affected on the production and the ecological environment of human beings.Especially the arid and semi-arid regions in northwest of China, due to its special geographical position, natural condition, the ecological environment extremely sensitive,and people’s living environment can not be protected. Therefore, the study of soil salt problem in arid areas is top priority of regional agriculture sustainable development. This paper relyed on the statistical methods ArcGIS10.0 and SAS9.2, based on 2013 to 2014 field sampling data obtained on the basis of the study area, analysing the valley basin irrigation farmland soil salt composition, distribution and different space-time change law in Turpan city farmland.The results show that:(1)The soil salinization in Turpan city is mainly composed of sulphate. 2.7% are salt,and salt mainly concentrated in the Daheyan river’s downstream desert terrain.With the increase of the depth,the soil salt ion content decreases,the list of clustering is 0.78,so base ions distribution is SAP. In irrigation period,the soil salt ion variability changes more seriously than the designated time. The surface soil salt ions present stronger spatial variability.(2) The HCO3-content has a significant correlation with soil’s total alkalinity.The SO42- and CI –content have a close relationship with the salt content of soil. Soil ion content has a obvious top-down vertical differentiation characteristics in the soil profile. Between the stage irrigation and irrigation period, the surface soil salt content is higher than that of the subsoil, the overall trends is stage irrigation period stronger than the irrigation period.(3)The Daheyan river’s soil salt content increases gradually from upstream to downstream, Taerlang river’s,too. The Meiyao river and Heigou river’s soil salt content decreases gradually from upstream to downstream,may cause Heigou river is in Turpan basin center,which is flattens;The Meiyao river’s soil salinity changes isminimal from upstream to downstream. Soil salinity variability is middling performance in May, the layers of soil salt’s fitting model conform to the Linear model and Exponential model respectively; Soil salinity variability is weak in November, the layers of soil salt’s fitting model conform to the Exponential model and Gaussian modelrespectively.(4) The soil salinity is changed, may cause of the geography, topography, river hydrology,building water conservancy projects, Karez and the artificial fertilization policy.