大荔枣园土壤养分空间分布及土壤肥力综合评价

为探究大荔县冬枣产区土壤肥力状况，采集了303个有代表性枣园土壤样品，测定了土壤pH、有机质、硝态N、铵态N、碱解N、有效P、速效K、有效Fe、有效Mn、有效Zn、有效Cu等指标，用ArcGIS软件绘制了土壤有机质和速效N、P、K的空间分布图，并应用主成分分析方法对枣园土壤肥力状况进行了综合评价。结果表明，pH值在各个采样点间的变异性较小，其余土壤肥力指标都存在着较大的变异，并且偏度和峰度>0，属于右偏态尖峰型；整体来看，大荔枣园土壤pH偏碱性，碱解N含量较为丰富，有效P含量中等偏低，速效K含量极其丰富，有机质含量较为缺乏。空间分布规律表现为土壤碱解N、有机质规律一致，东北区域低、其他区域高；有效P含量北部高南部低；除东北部少数区域外，土壤速效K含量普遍达到丰富或极丰富水平。主成分分析显示，有机质、速效K、有效Fe和有效P是影响冬枣园土壤肥力最主要的因素，通过对各乡镇的综合得分均值进行比较，发现各乡镇土壤得分高低与土壤养分空间分布结果相吻合。

Spatial Distribution of the Soil Nutrients and Comprehensive Evaluation of Soil Fertility in Jujube Orchards in Dali

In order to understand the soil fertility status of the winter jujube production in Dali County,Shaanxi Province,303 soil samples were collected from the jujube orchards and soil pH,organic matter and some nutrient contents were measured.The spatial distribution maps of soil organic matter and available N,P,K were drawn by ArcGIS software,and the method of principal component analysis was adopted to comprehensively evaluate the soil fertility situation of jujube orchards occurring in Dali.The results showed that soil pH had small variations while soil nutrient contents had significant variations with the over zero skewness and kurtosis,belonging to right skewness peak type.In general,the soil was alkaline,the alkali-hydrolyzable nitrogen was rich,the content of available phosphorus was low to the intermediate level eve,the available potassium was extremely rich,and the content of organic matter was insufficient.Both the soil alkali-hydrolyzable nitrogen and organic matter content were low in northeast area and high in other areas.The available phosphorus content was high in north and low in south.The soil available potassium was generally in rich or extremely rich level except for a few areas in northeast.The principal composition analysis showed that organic matter,available potassium,available iron and available phosphorous were the main factors contributing to soil fertility in winter jujube orchard.The soil fertility scores of each township were consistent with the spatial distribution of soil nutrients content.