曲靖市坡耕地土壤养分的空间变异性及其与利用方式的关系

Spatial Variability of Soil Nutrients and Their Relationship with Different Land utilization Types in Sloping Farmland in Qujing

以云南省曲靖市麒麟区越州镇面积为1 km2的典型性坡耕地为研究区,应用常规统计学方法和地统计学方法,对土壤的全氮、全磷、全钾、碱解氮、速效磷、速效钾、pH和有机质的空间变异规律进行分析,探讨了土地利用方式与土壤养分变异的关系。结果表明:研究区土壤养分空间变异程度以pH值最小,速效磷最大。速效养分、有机质和pH受人为活动影响明显,它们的空间自相关性中等或较弱。有机质、全磷、全钾、碱解氮、速效磷和速效钾等主要养分呈现出西北-东南方向逐渐增高的空间格局,与海拔和地形走势有明显相关性。不同坡位(坡位高低)间的土壤养分差异显著,有机质、全磷、全钾、碱解氮、速效磷和速效钾等养分指标呈现随坡位下降而升高的趋势。土地利用方式对土壤养分含量空间变异性也有明显的影响,施肥强度大的水田土壤养分含量最高,其次为施肥中等的旱地,土壤养分最低的是施肥量小或不施肥的果林和桉树林。

The objective of this study was to determine spatial variability of soil nutrients and their correlation with different land utilization tyoes on sloping farmland in Qujing region, Yunnan Province. Total N, total P, total K, available N, available P, available K, OM and pH of soil samples were examined and analyzed by conventional statistics and geo-statistics. The soil samples were taken from lkm2 sloping farmland on northwest highland of Qujing. The results showed that CV of pH was the lowest and CV of available P was the highest in all analyzed samples. Spatial variability of available nutrients, OM and pH were moderate or weak, because they had been greatly affected by human activities. The spatial variability pattern for whole study area was that main nutrients, such as OM, total P, total K, available N, available P and available K, and they were from low to high in the direction of northwest to southeast, and directly correlated with the altitude and topography. Difference of soil nutrients in different positions of the slope was Contents of OM, total P, total K, available N, available P the slope. Different land utilization greatly affected spatial significant. and available K increased dramatically in lower positions of variability of soil nutrients. Contents of soil nutrients varied with different cropping systems and land management.