【摘要】 测定了陕西杨凌示范区不同日光温室栽培土壤剖面的养分含量及变化。结果表明,日光温室土壤有机质、硝态氮、有效磷和速效钾含量呈现显著累积趋势,其中以0~20 cm土层有机质、0~40 cm土层有效磷和速效钾以及0~200 cm土层硝态氮累积量尤为突出。蔬菜生长过程中温室土壤剖面中铵态氮含量的变化相对较小,而硝态氮含量呈逐渐降低趋势。蔬菜收获后土壤剖面(0~200 cm)硝态氮残留量在707~1 161 kg/hm2之间,平均达954kg/hm2,明显高于农田土壤。温室栽培条件下土壤电导率明显高于农田土壤,以土壤表层尤为突出。土壤硝态氮、有效磷和速效钾与土壤电导率之间的关系均达显著水平,其中硝态氮含量与土壤电导率间的关系最为密切,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。更多还原

【Abstract】 Nutrient accumulations in soil under the vegetable cultivation in solar greenhouses have been investigated in Yangling,Shaanxi.It was found that the contents of organic matter in 0²0cm layer,available phosphorus and potassium in 0⁴0cm layer,and NO₃^——N in 0²00 cm of soil profiles were significantly increased.The contents of NH₄⁺-N in soil profiles remained stable during the growth of vegetable crops;however,the contents of NO₃^——N in 0²00 cm soil profiles were significantly decreased due to the uptake of NO₃^——N by vegetables.After the harvesting,the residual NO₃^——N in 0²00 cm soil profiles was in the range of 707¹ 161 kgN/hm²,with an average of 954 kgN/hm²,being notably higher than that in the crop field.The soil electric conductivities of greenhouses were higher than that of crop field,especially in the surface layer.There were close relationships between the soil electric conductivities and the contents of NO₃^——N,available phosphorus and potassium,and the correlation coefficient between NO₃^——N contents and soil electric conductivities was the highest,indicating that the excessive application of nitrogen fertilizer was the main reason to increase soil electric conductivities in greenhouses.更多还原