设施蔬菜栽培对土壤阳离子交换性能的影响

EFFECTS OF VEGETABLE CULTIVATION ON SOIL CATION EXCHANGE CAPACITY IN GREENHOUSE

以辽宁省沈阳市于洪地区设施菜地及其相邻旱田土壤为研究对象,测定土壤的有机质、阳离子交换量、交换性盐基离子组成和土壤盐基离子饱和度,分析设施蔬菜栽培对土壤阳离子交换量及交换性盐基离子组成的影响。结果表明:(1)与旱田土壤相比,设施土壤有机质含量明显增加,上下层土壤有机质平均含量分别为35.6 g kg-1和18.0 g kg-1,分别是旱田上下层土壤有机质含量的2.1倍和1.8倍;设施土壤阳离子交换量呈上升的趋势,土壤阳离子交换量与有机质含量呈极显著正相关关系(r=0.603**,n=50,r0.01=0.361)。(2)与旱田土壤相比,不同层次设施土壤交换性盐基总量均有所增加,交换性盐基离子中除交换性Ca2+含量变化不大之外,交换性K+、Mg2+、Na+含量均显著增加;不同层次设施土壤交换性K+、Mg2+、Na+饱和度显著高于旱田土壤,但交换性Ca2+饱和度和盐基饱和度呈下降趋势。

Soil samples were collected from vegetable fields under greenhouse and upland fields in their vicinity in Yuhong District of Shenyang,Liaoning Province,China,for determination of organic matter,cation exchange capacity（ CEC）,exchangeable base composition and soil base ion saturation,and hence analysis of effects of vegetable cultivation on soil cation exchange capacity in greenhouse. Results indicate：（1） the protected fields were much higher than the control（ upland field） in soil organic matter content,being about 35. 6 g kg- 1and 18. 0 g kg- 1or 2. 1 and 1. 8 times higher in mean content in the upper and lower soil layers,respectively; and the soil in the former displayed a rising trend in CEC; and an extremely significant and positive relationship between organic matter content and CEC; and（ 2） in the vegetable fields,total soil exchangeable base increased somewhat in all the soil layers,with exchangeable K＋,Mg2 ＋and Na＋,doing significanty,and soil exchangeable Ca2 ＋remaining almost unchanged; and the former three ions were much higher in saturation degree than those in the control,while the latter was lower in saturation degree and so was the soil base.