潮白河中游冲积平原土壤养分空间变异特征及其影响因素

Spatial Variability of Soil Nutrient and its Controlling Factors in the Middle Reaches of Chaobai River

应用经典统计学和地统计学方法研究了潮白河中游冲积平原表层(0～30 cm)土壤养分的空间变异特征,分析了空间变异的主要影响因素及其影响机制。结果表明:研究区土壤有机质(SOM)、全氮(TN)、全磷(TP)、全钾(TK)含量分别为9.49±4.42 g kg^(-1)、0.77±0.26 g kg^(-1)、0.64±0.19 g kg^(-1)、21.18±1.32 g kg^(-1);SOM和TN含量总体水平较低,Ⅴ级(缺乏)面积占比均超过60%,TP和TK含量较高,前者达到Ⅲ级(中上)水平的面积占57.6%,后者达到Ⅱ级(丰富)水平的面积占94.7%;4项指标均具有明显的空间自相关性,结构性因素起主导作用;地下水位埋深能够影响可溶性养分流失的难易程度和土壤的腐殖化程度,对SOM、TN、TP均有显著影响;土地利用类型在土壤淹水条件、土壤通气条件、生物归还能力等方面形成差异,对TN有显著影响;成土母质通过土壤矿物成分显著影响TK含量;不同因素之间存在交互效应,不同母质在潮褐土和壤质石灰性潮土中的SOM含量差异显著,而在碱化潮土中该差异不明显;地下水位埋深在林地中的TN含量差异显著大于在其他土地利用类型中。

Spatial variabilities of top soil (0~30cm)nutrients and their dominating factors in the Middle Reaches of Chaobai River were analyzed by using the statistics and geostatistics methods.The results showed that the contents of soil organic matter (SOM),total nitrogen (TN),total phosphorus (TP),and total potassium (TK)varied in the range of 9.49±4.42g kg^-1、0.77±0.26g kg^-1、0.64±0.19g kg^-1,and 2.12±0.13g kg^-1,respectively.The contents of SOM and TN generally were at low levels,over 60% of the study area with Ⅴ(lack)level.The contents of TP and TK generally were at high levels,57.6% of the study area with Ⅲ (above the average)rating of TP content and 94.7% with Ⅱ (rich)rating of TK content.There was very strong spatial autocorrelation among all four soil nutrients and structural factors played dominating roles in their spatial variabilities.Groundwater depth influenced the loss of soluble nutrient and the degree of humification,which lead to the significant differences in the contents of SOM,TN and TP.Land use types had significant impacts on TN content due to their different soil flooding and aeration conditions,biological returning capacity,and so on.Soil parent materials had extremely significant effects on TK content because of their difference in soil mineral composition.Interaction effects were presented among the factors.There were significant differences between different soil parent materials in meadow cinnamon soil and calcareous fluvo-aquic soil rather than in alkaline meadow soil,and between different groundwater depths in woodland rather than in the other landuse types.