华北太行山前平原农田土壤养分的空间变异性研究

采用地统计方法，分别对栾城县(面积约30490hm^2)和中国科学院栾城生态农业试验站示范区(15hm^2)农田耕层土壤养分的空间变异特征进行了研究．结果表明，在2个不同采样间距下，各土壤养分含量均具有空间相关性，县域范围近似以1km网格采样，最大相关距离为4．2～15．6km，在示范区以20m网格采样，则为112～223m；在同一采样间距下，土壤有机质、全氮、全磷、速效养分(N、P、K)含量的空间变异结构也各不相同，具有块金方差效应，半方差图分别遵从高斯和球函数模型．认识本区土壤的这种空间变异结构有助于实现对农田土壤养分的分区和合理管理．

Spatial variability of farmland soil nutrients at Taihang piedmont

By the method of geostatistics, this paper studied the spatial variability of soil nutrients in 30,490 hm2 crop field in Luancheng region and in 15 hm2 experimental field in Luancheng Ecological Agriculture Station of Chinese Academy of Sciences. The results showed that the variation of soil nutrient contents differed obviously, and the semivariograms could be simulated by Gaussian and spherical models with some nugget variances. The limit distance of spatial correlation was 4.2-15.6 km and 112-223 m in Luancheng region and in experimental field, respectively, and the spatial variability of soil organic matter, N, P and K was of semivariance structure. It revealed that there existed a spatial correlation in soil nutrient contents under relatively large-block scale, which made it possible to develop regionalized soil nutrient precision management.