长期施肥对菜地土壤氮磷钾养分积累的影响

以皖北地区菜地土壤为供试土壤,以其相邻粮田为对照,研究了菜地土壤氮磷钾含量变化及其分布特征,结果表明:经过长时间种植蔬菜,菜地土壤氮磷钾养分发生了不同变化,与一般粮田相比,菜地土壤铵态氮含量没有发生明显变化,而菜地土壤硝态氮含量明显增加,菜地土壤0￣60cm土层中硝态氮含量一般为相邻粮田土壤的3￣20倍;菜地土壤磷素积累特别明显,主要积累于0￣40cm土层中,菜地土壤全磷积累量为粮田的1￣5倍,有效磷积累量为粮田的7￣20倍;菜地耕层土壤速效钾含量也明显高于粮田土壤,为粮田土壤的0.6￣4倍左右。种植蔬菜时间越长,土壤养分积累量越高。

Effect of Long-term Fertilization on the Accumulation of Nitrogen, Phosphorus and Potassium in Vegetable Soils

Change and distribution characteristics of nitrogen, phosphorus and potassium content in soil profile were studied to evaluate the effect of long-term fertilization on vegetable soil in north of Anhui province. The results showed that, nitrogen, phosphorus and potassium content of vegetable soils changed differently. Furthermore, there was no significant change existed in ammonium content of vegetable soil, while nitrate content of vegetable soil increased significantly after long-term cultivation of vegetables, when compared with neighbor cereal crop field, and nitrate content of vegetable soil in each layer from 0 cm to 60 cm was 3~20 times higher than that of cereal crop soil; Phosphorus accumulated significantly and it mainly accumulated in the layer from 0 cm to 40 cm. Total amount of phosphorus accumulation in vegetable soil was 1~5 times higher than that of in cereal crop soil, amount of available phosphorus accumulation was 7~20 times higher than that of in cereal crop soil and amount of available potassium content was 0.6~4 times higher than that of in cereal crop soil. The longer vegetables were cultivated, the more amounts of nutrition elements were accumulated.