下辽河平原不同水-肥条件下玉米地土壤养分收支及氮肥利用效率

 【目的】了解下辽河平原地区施肥与水分条件对玉米地土壤中氮、磷、钾养分收支以及氮肥利用效率的影响。【方法】利用持续16年的长期田间试验结果结合气象观测资料，对不同水肥条件下玉米农田养分收支与氮肥利用效率进行研究。【结果】施肥条件差异可使玉米移出农田的养分量高出无肥处理2～3倍。水分条件对农田养分移出量的作用虽不如施肥明显，但在较好的降水条件下，即使较为理想的施肥模式，玉米地土壤中养分仍有可能出现赤字；氮肥的施用加剧了土壤磷的赤字，而氮、磷肥施用可加剧土壤钾收支赤字，有机肥的施用可以使养分收支赤字得到缓解；水分条件的改善则加速了养分收支赤字的出现，但适宜的水分供给对氮肥利用效率的提高作用显著。【结论】在下辽河平原地区，水肥条件对玉米土壤养分收支有显著影响，水分条件适宜土壤养分收支出现赤字的可能性增大，但保持农业系统养分循环再利用并根据土壤肥力适当施用化肥，既可满足作物丰产的养分需求又有利于平衡土壤养分收支，提高氮肥利用效率，减少农业对环境的影响。

Effect of Precipitation and Fertilization on Maize Farmland Nutrient Budget and Fertilizer-Nitrogen Use Efficiency in Low Reach of Liaohe River Plain

【Objective】The effects of fertilization and precipitation on the nutrient budget of N, P, and K in farmland soil and the Fertilizer-nitrogen use efficiency were studied. 【Method】 The results of a consecutive sixteen years field trial and meteorological observation data were used. 【Result】 The quantity of maize nutrients transferred from the system increased by a factor 2～3 in different fertilization conditions and it was more significantly influenced by fertilization than precipitation. But the precipitation was very important to increase Fertilizer-nitrogen use efficiency. Application of nitrogen fertilizer accelerated a large deficit of soil phosphorus, and the use of nitrogen and phosphorus accelerated the deficit of potassium. The process of deficit of soil nutrient was shortened with improving of precipitation condition. 【Conclusion】The use of recycled nutrients with an appropriate use of fertilizers according to the soil fertility could produce higher crop yields, balance soil nutrient budget, and reduce environmental pollution from agro-ecosystem.