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

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 geostatistics，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.