田块尺度下土壤磷素的空间变异性

采用经典统计学与地统计学相结合的方法,对中国科学院沈阳生态实验站30 m×42 m样地进行网格法分层(0～10和10～20 cm)取样,研究了田块尺度下土壤全P和Olsen-P的空间变异特征.结果表明,49对样本土壤Olsen-P的变异系数(4.5%～5.42%)远高于全P(11.8%～13.33%);全P和Olsen-P具有较好的空间结构且具有较相近的空间相关距离.最佳理论模型的参数显示各变量空间变异主要受结构性因素的影响,各变量半方差变异函数的C/(C₀+C)均高于%.全P和Olsen-P之间及在2个土层之间均具有较相似的空间分布格局.变异系数结合空间格局分析可以大大降低试验取样的数量.

Spatial variability of soil phosphorus in field scale

In this paper, the spatial variability of soil total P and Olsen-P at the depths of 0 approximately 10 and 10 approximately 20 cm in a field-scale was examined by using traditional statistics combined with geostatistics methods. A sampling grid of 30 m x 42 m including 49 pairs of soil sampling points was established in the Shenyang Experimental Station of Ecology, Chinese Academy of Sciences. The results showed that the variance coefficients were much higher for Olsen-P (46.56% approximately 56.42%) than for total P (11.68% approximately 13.33%). Both total P and Olsen-P in the two soil depths had strongly spatial structures and similar spatial correlation ranges. The parameters derived from best-fitted models showed that the spatial variability of both total P and Olsen-P was mainly affected by structural factors, with C/(C0 + C) being higher than 66% for all the variables. The kriging contour maps showed that both total P and Olsen-P in the two soil depths had similar spatial distribution patterns. A more precise sampling scheme could be made based on the spatial distribution pattern of test soil properties combined with traditional variance coefficients. To recognize the strong variability of soil Olsen-P in field-scale is of significance for better understanding the P cycling in farm ecosystems and for precise agriculture.