贵阳市开阳县植烟土壤有效中量元素调查与分析

Investigation and Analysis of Available Secondary Elements in Tobacco-planting Soil in Kaiyang County of Guiyang City

为明确贵阳市开阳县植烟土壤中量元素状况，科学补充烟田中量元素，对开阳县79个植烟土壤样本交换性钙、镁及有效硫含量进行了测定，并分析其分布状况。结果表明：开阳县植烟土壤交换性钙含量在1．14～30．41 cmol／kg范围内，平均交换性钙含量为9．51 cmol／kg，有34．18％的土壤较缺钙，宅吉植烟土壤交换性钙最高，冯三最低。交换性镁平均为2．36 cmol／kg，有12．66％的土壤缺镁。土壤交换性钙镁比在0．67～16．91范围内，平均为4．49，有67．09％的土壤存在生理性缺钙的风险。钙镁比值与交换性镁含量呈显著负相关关系，相关系数为－0．255。随着土壤pH值的增加，土壤交换性钙、镁含量逐渐增加，特别是交换性钙增加显著。土壤有效硫含量较丰富，平均为30．88 mg／kg，有18．99％的土壤存在缺硫或潜在缺硫。

In order to make clear the status of secondary elements in tobacco-planting soil in Kaiyang county of Guiyang city , and provide basis for the scientific supplement of secondary elements in tobacco field , we determined the contents of exchangeable calcium, exchangeable magnesium , and available sulphur in 79 tobacco-planting soil samples collected from Kaiyang county , and analyzed their distribution status .The results indicated that the exchangeable calcium content in tobacco -planting soil varied from 1. 14 cmol/kg to 30.41 cmolk/g , with an average of 9.51 cmol/kg;34.18%of soil samples were relatively deficient in calcium;the to-bacco-planting soil samples from Zhaiji contained the most exchangeable calcium , while those from Fengsan contained the least ex-changeable calcium .The average content of exchangeable magnesium in the soil was 2.36 cmol/kg, and 12.66%of soil samples was short of magnesium.The ratio of exchangeable calcium content to exchangeable magnesium content （Ca-Mg ratio） in the soil ranged from 0.67 to 16.91, with an average of 4.49;the physiological calcium lack risk existed in 67.09%of soil samples .There was a sig-nificantly negative correlation between soil exchangeable magnesium content and Ca -Mg ratio, and the correlation coefficient was 0. 255. Along with the increase in soil pH-value, the soil exchangeable magnesium content increased gradually , and the soil exchange-able calcium content increased significantly .The available sulphur content in the soil was relatively high , with the mean of 30.88 mg/kg.Among the soil samples collected , 18.99%of them lacked or potentially lacked in sulphur .