不同取样尺度农田土壤速效养分空间变异特征初步研究

Primary study of spatial variability of available soil nutrients in farmland with different sampling intervals

以3种取样间距(100m、50m、25m)进行网格取样,对土壤速效养分的空间变异性进行研究。结果表明:取样间距对土壤速效养分的含量水平、变异系数影响不显著;取样间距对合理取样数目具有一定的影响,合理取样数目分别为:碱解氮(71)、速效磷(36)、速效钾(18)。土壤速效养分的空间变异性主要受结构因素影响,但碱解氮与速效磷受随机因素影响强于速效钾。利用Kriging内插法绘制了不同取样间距土壤速效养分的等值线图。

The grid-sampling method was used to study spatial variability of available soil nutrients. The results showed that the sampling intervals did not significantly affect the contents and variance coefficients of available soil nutrients; they affected the proper sample number to some extent and the proper number should be 71 for alkali-hydrolysable nitrogen, 36 for available phosphorous, and 18 for available potassium. The spatial variability of available soil nutrients were mainly affected by structural factors but chance factors affected alkali-hydrolysable nitrogen and available phosphorous more than available potassium. The contour map of the available soil nutrients at different sampling intervals were depicted with Kriging interpolation method.