黑龙江省双城市土壤有机质和速效养分的空间变异特征

Spatial Variability of Soil Organic Matter and Some Available Nutrients in Shuangcheng,Heilongjiang Province

采用地理信息系统（GIS）和地统计学相结合的方法研究了黑龙江省双城市土壤表层（0-20cm）有机质、速效氮、速效磷、速效钾这4种土壤养分指标的空间变异性。结果表明：土壤有机质、速效氮、速效钾的理论模型均为球状模型；速效磷的理论模型为指数模型。速效钾含量的C0／（C0＋C）为49.96％，存在中等的空间相关性，说明其空间变异是由随机性因素和结构性因素共同作用的结果；速效氮、有机质、速效磷含量的C0／（C0＋C）变化范围是8．10％-14．39％，均表现出强的空间相关性，说明其空间变异均受结构性因素的影响。从总体分布趋势来看，4项养分指标均呈现出由西向东、由西南向东北升高的趋势。

Geographical information system （ GIS） combined with Geostatistics was applied to reveal the spatial variability of soil nutrients including organic matter, available N, available P and available K in the topsoil l0 ～20cm） in Shuangcheng Heilongjiang Province. The results showed that theoretical semivariogram models of organic matter, available N, available K were best described with a spherical model, whereas the available P was best fitted with an exponential model. The ratios of nugget to sill of available K was 49. 96% , indicating that the spatial correlation was moderately spatially dependent and the spatial variability was affected by structural and random factors together, while organic matter, available N and available P were from 8. 10% to 14. 39%, indicating that the spatial correlation were all strongly spatially dependent, and the spatial variability was affected by structural factors. The findings indicate that the contents of four nutrients were enriched from west to east and from southwest to northeast.