日光温室土壤养分含量及比例与种植年限的关系

对陕西省泾阳县的日光温室蔬菜施肥情况与土壤养分状况进行了研究。结果表明,泾阳县日光温室氮磷钾养分的纯投入量平均为N·651 kg hm~(-2)、P2O5·485 kg hm~(-2)和K2O·855 kg hm~(-2),养分投入量明显偏高。温室耕层土壤速效磷、速效钾、水溶性钾和水溶性钙与种植年限之间都存在极显著的线性正相关关系,相关系数分别为0.995、0.973、0.973和0.979。种植7年后,硝态氮、速效磷、速效钾的含量分别是农田土壤的1.8、5.1和3.6倍,水溶性钾、钙、镁分别是农田的12.2、4.5和2.6倍。随种植年限的延长,温室土壤K、Ca、Mg三者的比例严重失衡,由养分不合理施用带来的养分损失及可能引起的环境问题值得关注。

Relationships between Content and Ratio of Soil Nutrient and Cultivating Years in Solar Greenhouse

The study surveyed the application of fertilizers in greenhouse,and measured the contents of available nutrients in soil profile in the Jingyang County.The results showed that the average application amounts of nitrogen,phosphorus,and potassium fertilizers were N 651 kg hm-2,P2O5 485 kg hm-2 and K2O 855 kg hm-2 respectively.Over -application of fertilizers was very serious in the vegetable cultivation.The content of soil available phosphorus,available potassium,water soluble potassium and water soluble calcium had significant linear positive correlations with cultivation years,with correlation coefficient of 0.995,0.973,0.973 and 0.979,respectively.After 7 years of greenhouse cultivation,the contents of nitrate nitrogen,available phosphorus and available potassium were 1.8,5.1 and 3.6 times of that in neighboring crop field;and the contents of water soluble potassium,calcium and magnesium were 12.2,4.5 and 2.6 times of that in crop field.Along with the increase of planting years,the balances between potassium,calcium and magnesium became severely unfavorable.Therefore,more attention should be paid to the loss of nutrients from soil profile owing to the inadequate application of fertilizers and environmental issues induced by over -application of fertilizers.