Spatial Variability of Soil Nutrients of Cultivated Land in Gaomi Area

Geostatistics combining with GIS was applied to analyze the spatial variability and spatial distribution of soil nutrients in Gaomi at county scale,including 9 soil nutrients of SOM,AN(alkaline hydrolyzing nitrogen),TN,available K,available P,Mn,Cu,Zn and B.The results showed that the variation coefficient of soil nutrients followed the order of P Zn K Cu B Mn AN TN SOM.P had the highest variation coefficient of 48.80%,while SOM had the lowest of 21.76%.The semivariograms of soil nutrients were best described by exponential model,except for that of Mn,which was best fitted by liner model.K,Cu and Zn had significant spatial self-correlation,and other nutrients had medium spatial self-correlation.The spatial self-correlation degree ordered as K Cu Zn B TN AN B SOM P Mn.The spatial correlation range of B was the highest of 28716 meters,and that of available Cu was the lowest of 1410 meters.Mn and B showed an obvious regularity in spatial distribution,with the content of Mn increased gradually from north to south,while content of B decreased gradually from north to south in the study area.SOM,TN and alkali-hydrolysable nitrogen showed a similar spatial pattern,Cu and Zn had no significant geographical trends,and the high value areas of K and P spatial distributed sporadically.This study revealed the spatial distribution of soil nutrients in Gaomi,which had a positive significance for precision agriculture and sustainable use of land resource.