湘西州植烟土壤pH和中微量元素分布及其相关关系

Distribution characteristics of pH and medium/trace elements in tobacco planting soils in Xiangxi Autonomous Prefecture and their relationship

为揭示湘西州植烟土壤pH和中微量元素分布特征及其关系,于2015年采集湘西烟区1 242个土壤样本,采用分组回归和灰色关联方法分析了湘西州植烟土壤pH和中微量元素适宜性分布、县域分布以及pH与中微量元素的量化关系。结果表明:(1)湘西烟区植烟土壤pH变幅为4.17~8.17,平均值为6.12;处于植烟土壤pH适宜范围(5.5~7.0)内的样本占34.06%。(2)植烟土壤交换性钙和有效硼含量适宜,交换性镁、有效锌和有效钼含量(质量分数)较丰富,有效硫、有效铁、有效锰、有效铜含量(质量分数)偏高或过高。(3)主产烟县植烟土壤pH和中微量元素差异极显著。(4)植烟土壤交换性钙、交换性镁含量存在随土壤pH升高而升高的趋势,有效钼、有效铁、有效硫、有效铜含量存在随土壤pH升高而降低的趋势,有效锌、有效硼、有效锰含量与土壤pH间为曲线关系。(5)土壤pH对中微量元素的影响大小排序依次为交换性钙>交换性镁>有效硼>有效锌>有效钼>有效铜>有效锰>有效硫>有效铁。

To establish the distribution characteristics of pH and medium/trace elements in tobacco planting soils in Xiangxi Autonomous Prefecture and their relationship, 1 242 soil samples were collected from the main tobacco planting areas in Xiangxi in 2015, and the suitability distribution and county level distribution of pH and medium/trace elements in tobacco planting soils from Xiangxi and their quantitative relationship were studied by grouped regression and grey correlation analyses. The results showed that： 1） pH of tobacco planting soils in Xiangxi ranged from 4.17 to 8.17 with the average value of 6.12; the samples with suitable pH （5.5-7.0） for tobacco plantation accounted for 34.06%. 2） The contents of exchangeable calcium and available boron in tobacco planting soils in Xiangxi were suitable for tobacco cultivation, the contents of exchangeable magnesium, available zinc and available molybdenum were rich, and the contents of available sulfur, available iron, available manganese and available copper were slightly or over higher. 3） There were extremely significant differences of pH and medium/trace elements in soils among the main tobacco planting counties. 4）With the rise of soil pH, the contents of exchangeable calcium and exchangeable magnesium increased, while the contents of available molybdenum, available iron, available sulfur and available copper decreased; and the relationships between the contents of available zinc, available boron and available manganese with soil pH were curved type. 5）The effects of soil pH on medium/trace elements were in the rank of exchangeable calcium〉 exchangeable magnesium 〉 available boron 〉 available zinc 〉 available molybdenum 〉 available copper 〉 available manganese 〉 available sulfur 〉 available iron.