中国农业大学上庄实验站土壤理化性质的空间分布特征

Spatial variation of physico-chemical properties in Shangzhuang experimental station of China Agricultural University

对中国农业大学上庄实验站面积约70hm。的试验区布设了68个观测点，驯定了其表层土壤基本理化性质（质地、容重、pH、电导率、速氮、速磷、速钾、有机质、微量元素等）。应用传统统计学和地统计学方法对数据进行分析。结果表明：除pH变异系数为0．02外，其余土壤理化性质的变异系数范围为0．12～0．77，均属中等变异强度。半方差函数分析结果表明：除微量元素Mn和Zn表现为纯块金效应外，其余土壤理化性质在一定范围内均存在空间相关关系。其中表层土壤颚粒组成和阳离子交换量的空间相关距离最大。表现在全区均有相关性；其次，CaCO3含量和速效Fc的空间相关距离较大，分别为603m和541m；其余土壤理化性质的相关距离范围为180～477m。采用Kriging最优内插方法对未测点进行了估值，并绘制了土壤理化性质的空间分布等值线图，分析表明其含量产生差异的主要原因是土壤母质、土地利用方式、施肥、耕作等因素的影响。

Sixty-eight topsoils were sampled in Shangzhuang experimental station of China Agricultural University, Soil texture, bulk density, pH, EC, available nutrients, soil organic matter and micronutrients were determined for each soil sample. Descriptive statistics and geostatistics were used to analyze the data and the results indicated that the coefficient of variation （CV） for soil pH was 0.02, and the CVs for the other soil properties were in the range of 0. 12-0.77, which belonged to middle intensity. Semivariance analysis showed that all the soil properties had the spatial correlation in some distances, except for soil available Mn and Zn. Soil texture and CEC had the largest spatial correlation distance and soil CaCO3 and available Fe had the second largest spatial correlation distance, which were 603 m and 541 m, respectively. The spatial correlation distances for the others ranged from 180 m to 477 m. The Kriging method was used to estimate the unobserved points and generated the contour map. The results showed that their content difference was mainly caused by soil parent material, land use type, fertilizer application and cultivation.