不同类型紫色土交换性钙镁含量及对烟叶钙镁分布的影响

为探讨江西紫色土交换性钙、镁含量及对烟叶钙、镁含量分布的影响,于2009年在江西紫色土烟区点对点采集土样和烟样进行了化验分析。结果表明,江西紫色土交换性钙含量丰富但变异较大,交换性镁含量偏低且交换性钙、镁比值较大,导致烟叶含钙量变异较大且烟叶含镁量较低;烟叶含镁量为中性紫色土>酸性紫色土>碱性紫色土;中性紫色土烤烟不同叶位烟叶含钙、镁量差异不大,但碱性与酸性紫色土烤烟均为上部烟叶含钙、镁量高于中下部叶;土壤交换性钙、镁之间呈极显著正相关,交换性钙、镁与土壤pH、有机质和氮、磷、钾、硫之间具有一定的相关性,但交换性钙与微量元素呈极显著负相关。

Exchangeable Ca and Mg Contents in Various Purple Soils and their Effects on Ca and Mg Contents in Flue-cured Tobacco

In order to understand the contents of exchangeable Ca and Mg in different types of purple soils of Jiangxi and their effects on nutrients (Ca, Mg) distribution of flue-cured tobacco, the soil and tobacco samples were collected by point to point approach (namely the location of soil sample was same to that of the tobacco sample) in purple soil area of Jiangxi and were then determined in 2009. The results showed that in Jiangxi's purple soils, the exchangeable Ca was sufficient and greatly variable, while the exchangeable Mg was low and the ratio of exchangeable Ca to Mg was high, so the concentration of Ca in leaves was variable and the concentration of Mg was low;the concentration of Mg in tobacco leaves was neutral purple soil >acid purple soil >alkaline purple soil. In the neutral purple soil, the concentrations of Ca and Mg in difference position of leaves were not significant difference, but in the acidic and alkaline purple soils the concentrations of Ca and Mg in the upper leaf were higher than those in the middle and lower leaves. Soil exchangeable Ca was significantly positive correlation to Mg, and also was positively correlative to pH, organic matter, nutrients (N, P, K, S), and was extremely significant and negative correlated to soil trace elements.