江门市新会区耕地土壤养分空间变异特征

运用地统计学方法,结合GIS技术研究了江门市新会区土壤pH值、有机质、阳离子交换量、全氮、有效磷和缓效钾种养分要素的空间分布特征.结果表明,各变量符合正态分布或经对数转换后符合正态分布.半方差函数分析结果显示,除全氮具有强空间相关外,其余均具有中等空间相关性.Kriging插值结果表明,研究区域耕地土壤pH值和阳离子交换量在东北部最高,有机质含量在中部和东北部较高;全氮含量在1.5～2.0g·kg^-1的面积占研究区域耕地面积的74.7%,主要分布于研究区域西部和东部地区;有效磷含量＞40mg·kg^-1的面积占研究区域耕地面积的48.7%,主要分布于研究区域东北部和西部;缓效钾含量在10～350mg·kg^-1的面积占研究区域耕地面积的48.1%,主要分布于研究区域东部、东北部和中部.

Spatial variability of nutrients in cultivated soils of Xinhui District,Jiangmen City

Employing geostatistical methods and GIS technology,this paper studied the spatial distribution characteristics of pH,organic matter,CEC,total nitrogen,available phosphorus and slowly available potassium in cultivated soils of Xinhui District,Jiangmen City.All the test variables were normally or log normally distributed.Semivariogram analysis showed that soil nutrients were moderately spatially-dependent in a given spatial range,except that soil total nitrogen was strongly spatially-dependent.It was shown from Kriging analysis that soil pH and CEC was the highest in the northeast,and soil organic matter content was higher in the middle and northeast investigation region.The area with 1.52.0 gkg~(-1) soil total nitrogen content accounted for 75.7% of the investigated region,mainly distributed in the west and east,that with >40 mgkg~(-1) soil available phosphorus content was accounted for 48.7%,mainly distributed in the west and northeast,and the area that slowly available potassium content was 160350 mgkg~(-1) accounted for 48.1%,mainly distributed in the east,northeast and the middle.