干旱区冲积平原绿洲土壤养分的时空变异性研究——以新疆农八师121团为例

Spatio-temporal Variability of Soil Nutrients in Alluvial-plain Oasis in Arid Zone ——A Case Study of the Regiment 121 in Xinjiang

以新疆农八师121团为研究区,根据1982年第二次全国土壤普查养分数据和2004年5月采样获得的土壤养分数据,利用地统计学和GIS空间分析技术,研究了冲积平原绿洲土壤养分的时空变异性。结果表明:速效钾具有强烈的空间相关性,全氮、速效磷和碱解氮具有中等的空间相关性;而全磷和有机质则从1982年具有强烈空间相关性逐渐演变为2004年具有中等的空间相关性。分析认为:长期的耕作、施肥的变化、种植结构的变化等随机性人为因素,导致全氮、速效磷、碱解氮、全磷和有机质从主要由气候、母质等结构性因素影响逐渐演变为结构性因素和人为因素共同影响,尤其是全磷和有机质受到人为因素的影响逐渐加大;而速效钾则主要受研究区域土壤母质、土壤类型等的影响。

Taking the Regiment 121 of the 8th Agricultural Division,located in the manasi oasis in the north slope of Tianshan mountain,in Xinjiang,as the study area,the paper analyzed the spatio-temporal variability of soil nutrients by the combining method of geostatistics,traditional statistics analysis and GIS technique.The results showed that：the contents of soil organic matter decreased significantly from 1982 to 2004,whereas the total N,total P,available N,available P and available K increased obviously,which suggesting,after twenty-two years of cultivation and fertilization,N and P contents in soils has significantly increased. The Nugget/Sill ratios revealed that spatial correlation of the available K belongs to a strong class,suggesting that spatial distribution was mainly affected by soil parent material,while available N and total N has a moderate spatial correlation,indicating theirs spatial distribution was jointly affected by soil parent material and fertilizer,cultivation etc.The Nugget/Sill ratios of total P and OM was increased to 39.11% and 45.51% in 2004 from 15.74% and 17.57% in 1982 respectively.The changes in the Nugget/Sill ratios indicated that the strong spatial correlation of the total P and OM has changed into a moderate spatial correlation,suggesting that the stochastic factors such as fertilizer,cultivation,irrigation and crop structure during the 22 years have affected,and the soil nutrients were gradually jointly affected by the structural factors and stochastic factors.The contents of soil organic matter,total N,total P,available N and available P in Manasi river oasis were lower than those in Sangong river watershed oasis,but the content of available K,was higher than that of Sangong river watershed in 1982,and lower than that in 2004.Spatial variability of soil nutrients and soil organic matter in Manasi river oasis was lower than that of Sangong river watershed oasis,which was probably related to high fertilization in long-term cultivation and crop in Sangong river watershed.