红壤蔗区土壤有效硅的空间变异特征

在一块面积约24 km2的低丘红壤蔗区中,测定了土壤表层175个土样的土壤有效硅含量,结果表明有效硅平均含量较低(117.7mg/kg),变异系数为中等变异强度。地统计学的空间结构分析表明,土壤有效硅存在中等程度的空间相关性,变程为5 km。Kriging方法绘制的等值线图显示,土壤有效硅的空间分布呈明显的斑块状,与地形分布有一定的相关性。通过估计值标准差分布图增补采样点可提高插值精度,为施肥管理提供依据。

Spatial variability of soil available Silicon in the sugarcane field of red soil area

175 soil samples were collected in a sugarcane field(approximately 24 km~2) in the hill region of subtropical China.The soil available Si were measured.The statistical results indicated that the mean value at a low level of 117.7 mg/kg,and the coefficient of variation belonged to the medium level.The geostatistical analysis revealed that the spatial correlation of the available soil Si was moderate,and the range of spatial correlation was 5 km.The contour map by Ordinary Kriging method showed that the spatial distribution of values of the soil available Si were spots in evidence.To a certain extent,a spatial similarity exists between the topography and the item.Addition samples from the spares places based on the map of estimated standard deviations could improve the interpolating precision that would be useful to conduct optimal fertilization.