施肥结构对砂质潮土有机质及氮磷钾养分变化的影响

通过在砂质潮土上10年长期定位试验，研究了不同施肥结构对作物产量和土壤有机质及N、P、K等养分在土体中变化的影响。结果表明，单施N肥小麦减产21.1％～34.3％，玉米则增产155.9％～209.7％；单施P肥小麦增产29.3％～39.7％，玉米减产50.4％～63.0％；而N、P肥配施小麦、玉米分别增产3.43～5.79倍和3.04～4.23倍。施有机肥能显著提高作物产量和土壤养分含量，而N、P肥单施或配施仅能维持较低有机质水平，且土壤K耗竭严重。单施N肥N素易于下淋，而N、P肥配施有利于N在土壤上层的保持。有机肥配施N肥或N、P肥是较好的施肥结构。

Effect of fertilizing structure on the change of organic matter and N,P and K nutrients in sand soil

Through long-term fertilizing experiment in sand soil ,the effects of different fertilizing structures on crop yield and the changes of organic matter and N,P and K nutrients in sand soil were analyzed. The results showed that wheat yield decreased to 21.1％～34.3％ and maize yield increased to 155.9％～209.7％ by solely applying of nitrogen fertilizer,wheat yield increased to 29.3％～39.7％ and maize yield decreased to 50.4％～63.0％ by solely applying phosphorus fertilizer,but they were increased by 3 43～5.79 times and 3 04～4. 23 times respectively by coordinate application of N with P fertilizer. Manure significantly raised crop yield and nutrient content of soil ,but no matter nitrogen and phosphate fertilizer were solely or coordinately applied ,organic matter only kept at low level, furthermore, soil potassium was heavily consumed. Nitrogen was easy to move down to lower soil layer when nitrogen fertilizer was solely applied, whereas it was favorable to nitrogen to be maintained at upper soil bed as nitrogen fertilizer was coordinately fertilized with phosphate fertilizer. The coordinate application of manure with nitrogen fertilizer or with nitrogen and phosphate fertilizer was optimum fertilizing structure.