基于GIS和地统计的伊犁州农田土壤养分空间变异特征分析

【目的】 研究土壤养分的空间变异程度及分布规律,为干旱区农业施肥区划及精准农业的推广提供理论依据。【方法】 以新疆伊犁州为研究区,运用GIS技术与地统计学相结合的方法,研究伊犁州农田土壤养分的空间分布特征及变异规律。【结果】 (1)AP、SOM均属于强变异强度,变异系数分别为0.82、0.79;其它土壤肥力指标变异系数处于0.60~0.67,均属于中等变异强度。(2)伊犁州土壤TN、SOM含量总体较高,较丰富以上的样点比例分别占66.66%、61.07%;其次为AK、AP,较丰富以上的样点比例分别占50.85%、49.37%,AN含量相对较低,缺乏和较缺乏的样点比例超过65.72%。(3)TN、SOM、AN表现为极强的空间相关性,其块基比分别为0.107、0.002、0.000 07;AP的块基比为0.403,在区域内表现为中等强度的空间自相关性;速效钾的块基比为0.755,在区域内表现为较弱的空间自相关性。(4)该地区土壤养分含量在空间分布上多呈斑块状格局。5个养分指标中,TN、AN含量的空间分布大体相似,含量较高的区域主要分布伊犁州的东部;SOM、AP含量的空间分布大体相似,含量较高的区域主要分布伊犁州的南部;AK含量的空间分布相对均衡。【结论】 研究区AK、SOM、AP平均含量均处于较高水平;TN、AN平均含量均处于较低水平。土壤养分含量空间分布总体呈现南高北低、东高西低的格局。

Spatial Variability Analysis of Soil Nutrients in Farmland of Yili Prefecture Based on GIS and Geostatistics

【Objective】 To study the spatial variability and distribution of soil nutrients, and provide theoretical basis for the fertilization zoning of agricultural areas in arid areas and the promotion of precision agriculture.【Result】 (1). Both AP and SOM belonged to strong variation intensity, and the coefficient of variation was 0.82 and 0.79, respectively. The coefficient of variation of other soil fertility indicators was between 0.60 and 0.67, which were all of moderate intensity. (2). The content of TN and SOM in the soil of Yili Prefecture was generally higher, and the proportion of the above-mentioned samples was 66.66% and 61.07%, respectively. The second was AK and AP. The proportion of samples above the richer was 50.85% and 49.37%, respectively. The rations of missing and scarce sample points exceeded 65.72%. (3) TN, SOM, and AN exhibit strong spatial correlation, with block-to-base ratios of 0.107, 0.002, and 0.000,07, respectively; AP's block-to-base ratio is 0.403, showing moderate spatial autocorrelation in the region; The quick-acting potassium has a block-to-base ratio of 0.755 and exhibits a weak spatial autocorrelation in the region. (4) The soil nutrient content in this area is mostly plaque-like in spatial distribution. Among the five nutrient indicators, the spatial distribution of TN and AN content is similar, and the higher content is mainly distributed in the eastern part of Yili Prefecture; the spatial distribution of SOM and AP content is similar, and the higher content is mainly distributed in the southern part of Yili Prefecture; The spatial distribution of AK content is relatively balanced.【Conclusion 】 The average contents of AK, SOM and AP in the study area were all at a high level and the average contents of TN and AN were at a low level. The spatial distribution of soil nutrient content generally showed a pattern of high in the north, low in the north and high in the east and west.