黄土高原东北缘退耕坡地土壤养分和容重空间变异特征研究

Spatial Variation of Soil Nutrients and Bulk Density in Rehabilitated Slope Land on Northeast of Loess Plateau

以山西广灵退耕6年的典型坡地为代表,在实地调查和取样分析的基础上,使用经典统计学和地统计学方法研究了黄土高原东北缘退耕荒草地中土壤养分与容重的空间变异特征。结果表明:研究区土壤容重较高、养分含量较低,土壤较为贫瘠,且土壤容重具有弱变异而土壤养分具有中等程度变异;同时,所研究土壤性质的合理采样数从多到少依次为全磷>有机质>速效磷>碱解氮>速效钾>全氮>容重;另外,该区土壤养分和容重的空间分布可用球状模型进行较好的拟合,而且其空间变化主要是人为等随机性因素作用的结果。

A representative slope land which was rehabilitated before 6 years was selected as experimental area in Guangling county of Shanxi province. In the area, the soil was sampled and then the soil properties including organic matter, total nitrogen, total phosphorus, available nitrogen, available phosphorus, available potassium and bulk density were measured. The experimental data was analyzed by classic statistical method and geostatistical method to explore the spatial variation of soil nutrients and bulk density in rehabilitated slope land on northeast of Loess Plateau. The results show that the soil bulk density has a weak variation and is a little higher than regular. Oppositely, the soil nutrients have a moderate variation and are fewer than regular. The descending order of reasonable sampling number of soil properties is total phosphorus 〉 organic matter 〉 available phosphorus 〉 available nitrogen 〉 available potassium 〉 total nitrogen 〉 bulk density. The distribution and variation of soil properties was mainly influenced by random factors including man-made factors rather than structural factors including such as natural factors. Also, the spatial distribution of soil nutrients and bulk density can be well fitted by spherical model. These results mentioned above will be useful for understanding spatial variation of soil properties at some extent in northeast of the Loess Plateau, China. It also will be very helpful for ecological restoration and sustainable land use in research region.