粤北山区耕地土壤肥力空间分布及综合评价研究

Research on spatial distribution of soil fertility and comprehensive assessment of cropland in mountain areas of north Guangdong

粤北山区是广东省重要的粮食产区之一，该地区以山地丘陵为主。以韶关南雄市黄坑镇耕地为例，利用地统计学、GIS和主成分分析法等相关的理论和方法，对研究区域耕地土壤肥力的空间变异特征、分布及综合肥力评价等方面进行研究。结果表明：研究区域耕地土壤碱解氮、有效磷含量非常丰富，平均值分别为186．25、40．39mg／kg，全氮含量中等，有机质、缓效钾、速效钾含量偏低；肥力元素变异系数在13％～69％之间，均为中等强度变异；碱解氮具有弱空间自相关性，有效磷、有机质、全氮、pH值、速效钾、缓效钾空间自相关性依次增强；土壤综合肥力总体中等偏低，从空间分布来看，土壤肥力东北及东部较高，中部、西南部相对较低。

The mountain area is one of the most important grain producing areas of Guangdong province, and the area is hilly. Taking the cropland of Huangkeng town in Shaoguan city as research object, the spatial variation characteristics, distribution and comprehensive evaluation of soil fertility of cultivated land in the study area were studied in detail, by the methods of geostatisties, GIS and principal component analysis. The results showed that, in the research area, the contents of soil available nitrogen and available phosphorus were very rich, and the average values were 186.25 mg/kg and 40.39 mg/ kg, respectively, the content of total nitrogen was moderate, while the contents of organic matter, slow-available potassium and available potassium were lower. The variation coefficient of soil fertility elements was 13%-69%, and the variation intensity was medium. Soil available nitrogen had a weak spatial autocorrelation, while the spatial autocorrelation of available＇ phosphorus, organic matter, total nitrogen, pH value, available potassium, slow-available potassium enhanced in turn. On the whole, the comprehensive fertility of soil was medium to low; from the spatial distribution, soil fertility in the northeast and eastern part was higher, that in the central and southwest was relatively low.