雷州半岛南部土壤肥力综合评价及空间变异

通过测定雷州半岛南部845个耕地土壤样品pH、有机质、全氮、有效磷、速效钾、碱解氮的含量,采用层次分析法确定各肥力评价指标权重,应用模糊数学法对该区域耕地土壤肥力进行综合评价,并利用ArcGIS 9.2软件对土壤肥力空间变异进行分析.结果表明:雷州半岛南部土壤有机质、全氮、有效磷、速效钾、碱解氮平均值分别为26.18 g/kg、1.48 g/kg 、34.63 mg/kg、158.57 mg/kg、133.17 mg/kg;土壤速效磷的变异系数最高,为103.14%,属强变异性,有机质、速效钾、碱解氮、全氮的变异系数属中等变异性,pH值的变异系数最小.土壤肥力总体水平处于中等偏低;从空间分布来看,土壤肥力中部高,东北、西南部相对较低

Comprehensive Evaluation and Analysis on Spatial Variation of Agricultural Soils Fertility in the Southern Leizhou Peninsula

To evaluate the agricultural soils fertility in Xuwen County in the southern Leizhou Peninsula,a total of 845 soil samples was analyzed for the content of pH,organic matter,total N as well as the available N,P and K.The assessment was performed by using the Fuzzy method with the weight of the each evaluation index determined according to the method of AHP.Furthermore,the spatial characterization of soils fertility was also obtained by using the geostatistical analyst extension of ArcGIS 9.2.As the results showed,the average content of soil organic matter,total N,available P,K and N were 26.18 g/kg,1.48 g/kg,34.63 mg/kg,158.57 mg/kg and 133.17 mg/kg,respectively.The available P had high variability with its coefficient of variability(CV) above 100%,and moderate variability was found for organic matter,total N as well as the available N and K.In addition,soil pH had low variability.Overall,the agricultural soils fertility in Xuwen County was at a middle or low level.As for spatial distribution,the fertility of soils in the central part and showed high level and low for northeast and southwest.