Study On Spatial Variability Of Soil Nutrients In County/Farm Region Based On Geostatistics

Due to the statistics usually requires uniform sampling; it brings certain difficulties to the larger regional variations in the quantitative study of soil nutrients. So the spatial variability of soil nutrient research in small-scale is more than large-scale. This literary is using Geostatistics combined with GIS in county/farm region to research, select the farm No 16, Yuepuhu County and Kuche County three region to research, analyze the spatial variability of soil nutrients including soil organic matter, available N, available P and available K in topsoil (0—20cm), and compare with three regions to explore a method of soil nutrients space variability analysis in county/farm region. The main results obtained are summarized as follows:The four types soil nutrient variability coefficient (CV) of these three areas are basically between 10~100%. Belonging to the moderately dependent, the characters of these changes are from structural factors and the random factors. Only 60% of available P in Kuche County is slightly high, other values are all around 30%.This is probably due to the soil nutrient level difference was not significant, farming practices, cultivation system is basically the same in these three areas. In the model selected. Only available P and soil organic matter of the farm No 16 are use spherical models, the other models are in line models.The four nutrient's proportions of C 0 /( C0+ C)are around 50%, which have shown the middle relevance. From the distance of space-related, except of available P, the other three basic elements in Kuche County and the Yuepuhu area are larger than the farm No 16, this may relative with sampling distribution.The decision coefficients of three areas are close to one. It proves fit better and more accurately. Through comparisons between the county and farm, soil organic matter, available N and available K of three regional distribute law to be comparatively average, which might be after long as three farming areas, fertilization, soil management by human factors undermined its home quality, climate, topography, and other inherent factors. But available P is respect of vulnerable to the effects by artificial fertilization, It reflecting the fertilization level, and can find out the available P content of the farm No 16 is higher than that of other two places through the data, which can indicate the manuring amount of the farm is larger than other two place. these three areas are all cotton growing areas, this is the reason why the cotton yield of the farm is higher than other county.Comparison between the three regions of the soil nutrient content, the soil organic matter content is below the middle level, available P is belongs to the high levels, available N and available K are the middle level. Generally the spatial variability of soil nutrients in these three different county and farm region under the influence of the human factor for a long time is becoming greater similarities and homogeneous variation tendency.