Spatial Variability of Soil Salt on the Surface of Cotton Fields in the South of Xinjiang

Fast and accurate simulation of the spatial distribution of soil salt from the study on soil spatial variability was the basis for precision agriculture and environmental protection.The electrical conductivity of the surface soil was measured through grid method in a cotton field(50 m×70 m) by soil conductivity meter called PET2000.The model was constructed,screened and validated by geostatistic module of ArcGIS9.2.Salinity spatial variation regularity of the surface soil(0—25 cm depth) in cotton fields was studied using the geostatistics at an interval of 5 cm.Spatial distribution of the salinity in the soil was predicted and the corresponding solution measures for salt accumulation of the surface soil in cotton fields were put forward.The results showed:(1) Rational Quadratic model was suitable for forecasting soil electrical conductivity.Salinity spatial variability of the surface soil in local cotton fields was obvious.The variation coefficient reached 0.578 and salinity spatial variability of the soil gradually decreased with increased depth;(2) Generation of spatial variability was mainly due to the spatial difference of the soil lithology and irrigation with brackish water;(3) To solve the problem of local salt accumulation in cotton fields,we should irrigate timely and spatially based on the analysis and forecast of spatial differential characteristics of soil salinity.Thereby,the water resources can be rationally used and the crop growth environment can be improved.