不同年限蔬菜温室土壤基本化学性质比较研究

本文对沈阳市郊大民屯镇不同年限蔬菜温室土壤化学性质进行研究与分析。得到主要结论如下： 蔬菜温室0～20 cm表层土壤有机质、全氮、速效磷、速效钾、铵态氮、硝态氮均处于较高的养分水平，并且随温室使用年限的延长，呈增加的趋势。土壤有酸化的趋势，土壤电导率呈升高态势。土壤有效态Fe、Mn、Cu、Zn含量分别为8.57～60.30 mg kg-1、2.69～22.43 mg kg-1、0.64～7.52 mg kg-1和0.56～9.29 mg kg-1，变异系数为50%左右；随着温室使用年限的增加，土壤有效态Fe、Mn、Cu、Zn含量总体上呈增加的趋势。土壤Ni、Cd的有效含量随种植年限的延长趋于增加，有效Pb呈现出下降的趋势，土壤重金属Cr的有效态含量与种植年限之间没有明显的相关性。 不同年限蔬菜温室土壤剖面有机质、全氮、速效磷及速效钾含量高于相邻的露地菜田土壤，并随种植年限的延长而增加，随土层深度的增加而下降。温室土壤中铵态氮的含量随温室种植年限的变化相对较小，在土壤剖面不同层次中变化也没有明显的规律性。与露地菜田土壤相比，温室土壤中有效态铁、锰含量下降，有效态铜、锌、铅、镍含量增加。0～30 cm土层土壤交换性Ca呈下降的趋势，交换性Mg呈上升的趋势，土壤Ca/Mg比值呈下降的趋势。

Soil chemical properties in vegetable greenhouse fields with different planting ages was examined, in Damingtun Township of Shenyang City, in order to offer basis for reasonable application of fertilizers to greenhouses. Following results were obtained: The contents of total organic carbon, total N, available P, available K, ammonia nitrogen and nitrate in vegetable greenhouse fields increased with the greenhouse plangting ages. The soil has showed obvious tendency to acidification and to salinization. The contents of soil available Fe, Mn, Cu, and Zn were 8.57～60.30 mg kg-1, 2.69～22.43 mg kg-1, 0.64～7.52 mg kg-1and 0.56～9.29 mg kg-1, respectively. The coefficient of variation was about 50% for test variables. Generally, soil available Fe, Mn, Cu, and Zn contents increased with the greenhouse planting ages. With increasing ages of greenhouse planting, the available contents of the metals Ni and Cd in soils all exhibited the increasing trend, while decrease in Pb, in the main. But no significant variation principle was observed for Cr. Total organic carbon, total N, available P and available K in soil profiles were obviously higher in vegetable greenhouse field than in the open field. The above mentioned indexes increased with the greenhouse planting ages and decreased with soil depth. No significant variation principle was observed for ammonia nitrogen. Compared with the open field soil, soil available Fe, Mn, and Pb decreased and soil available Cu, Zn, and Ni increased gradual1y in the vegetable greenhouse field. At the depth of 0-30 cm, soil exchangeable calcium decreased, and the ratios of exchangeable calcium and magnesium decreased, while the content of exchangeable calcium increased in the vegetable greenhouse field.