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连续2年对陕西杨凌地区设施栽培菜地土壤剖面的养分含量进行了测定。结果表明,菜地土壤有机质和全氮含量较农田明显增加,但与高产优质菜地对土壤有机质含量的要求相比,仍属较低水平。菜地土壤0～100cm剖面硝态氮含量以及耕层及20～40cm土层有效磷、有效钾含量均较农田土壤显著增加,表明养分特别是硝态氮在土壤剖面发生明显的淋溶作用,由此可能引起的环境问题值得关注。土壤硝态氮、有效磷和速效钾与土壤电导率间有密切的关系,其中硝态氮含量与土壤电导率间的关系更为密切,说明过量施用肥料特别是氮肥是引起土壤盐分累积的主要原因。
The nutrient contents of soil profiles in the cultivated vegetable fields in Yangling, Shaanxi Province were determined for two consecutive years. The results showed that the content of soil organic matter and total nitrogen in vegetable field increased obviously compared with that of farmland, but still lower than the requirement of organic matter content of soil in high yield and quality vegetable garden. The contents of nitrate nitrogen in 0-100 cm section of vegetable soil and available phosphorus and available potassium in topsoil and 20 ~ 40 cm soil layer increased significantly compared with farmland soils, indicating that nutrients, especially nitrate nitrogen, were obviously leached in the soil profile, The environmental issues that may be caused by this concern deserve attention. Soil nitrate nitrogen, available phosphorus and available potassium were closely related to soil electrical conductivity. The relationship between nitrate nitrogen content and soil electrical conductivity was closer, which indicated that excessive application of fertilizer, especially nitrogenous fertilizer, was the main cause of soil salt accumulation the reason.