Spatial variability of soil nitrate nitrogen after potatoes and its change during winter

摘要: Knowledge of the frequency distribution and spatial structure soil NO3-N is required to develop an efficient sampling strategy. A 1 ha polder field was sampled after harvest potatoes in October 1987, February April 1988, without being fertilitzed since March 1987. These data sets were examined by a classical statistical as well analysis. The found be lognormally distributed, showed normal distribution. All three had structure, although anisotropic needed removal trend. variability NO3−N decreased, became isotropic evolved towards larger range dependence during winter. this permitted krige or cokrige data. number samples estimate mean content with acceptable precision 39, 43 17 October, respectively.