邵阳植烟土壤pH时空特征及其与土壤养分的关系

为了解邵阳烟区植烟土壤pH时空特征及其与土壤养分的关系,采用传统统计学和地统计学及灰色关联方法分析了邵阳烟区植烟土壤pH状况、空间分布、演变趋势及其与土壤养分的定量关系。结果表明:①邵阳烟区植烟土壤pH总体上适宜,平均值为6.01,变幅为4.12~7.91,变异系数为11.98%,处于适宜范围内的样本占61.68%。②植烟土壤pH大小依次为邵阳县>隆回县>新宁县,3个县差异达极显著水平。③邵阳烟区植烟土壤pH呈斑块状分布态势,总体上有从北部、东部和西南部向中部递减的趋势,在新宁县的东北部有一个低值区。④隆回县和新宁县植烟土壤pH呈降低趋势,邵阳县植烟土壤pH呈上升趋势。⑤植烟土壤有机质、速效钾、交换性镁与土壤pH呈显著或极显著正相关;植烟土壤有效磷、有效锌、水溶性氯与土壤pH呈显著或极显著负相关。⑥土壤养分与土壤pH的关联顺序为:交换性镁>速效钾>有机质>有效磷>碱解氮>水溶性氯>有效硼>有效锌。

pH of Shaoyang tobacco-growing soils and their relations with nutrients

In order to understand soil pH of Shaoyang tobacco-growing areas and the relations with soil nutrients,pH,spatial distributionand changetrend of pHandtheir quantitative relationships with soil nutrients were analyzed by the methods of,and grey correlation analysis.The results were as follows：（1） pHs in tobacco-growing soils weregenerally suitable for tobacco cultivation with a mean of 6.01,amplitude of 4.12～7.91 and variation coefficient of 11.98%.About 61.68% of the soil samples was suitable for tobacco cultivation.（2）There were extremely significantdifferences among 3 county of tobacco-growingsoil pH; The soil pH for different counties werein the following order：Shaoyang county〉Longhui county〉Xinning county.（3）Kriging interpolation map indicated that the spatial distributions of pH were patchiness,while reduced from the north and eastand southwest to the middle.The lowvalue areasof pH were in some areas of the northeast Xinning county.（4） Thechangingtrend of pHin Shaoyang countywasincreasing,whilein Longhui county and Xinning counties were decreasing.（5） There were extremely significantor significantpositive correlationsbetween soil pHwith organic matter,available potassiumand exchangeable magnesium; whilenegative correlationsbetween soil pHwith available potassium,and water-dissolving chloride.（6）The grey correlation order was exchangeable magnesium〉available potassium〉organic matter〉available phosphorus〉availablenitrogen〉 water-dissolving chloride〉available boron〉.