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为了探讨连年施磷效果,于1983—1985年度进行了油菜和小麦的施磷试验。试验结果证明,不论油菜或小麦,施氮均有明显的增产效果,差异达极显著水平;施磷效果甚微,甚至反而引起减产,施磷水平间无显著差异。其原因是由于连年大量施用磷肥,加之磷肥利用率低,作物吸收的氮多磷少,氮素易挥发、淋溶、损失等,而使土壤中残留有一定量的磷素,氮素则相对显现不足,氮少磷多,比例严重失调,氮素成为最小养分因子所致。
In order to investigate the effect of successive years of phosphorus application, phosphorus was tested in rapeseed and wheat in 1983-1985. The results showed that there was a significant increase in N application rate in both rapeseed and wheat, and the difference was extremely significant. The effect of phosphorus application was very little, and even the yield was reduced, but there was no significant difference in phosphorus application rate. The reason is that a large amount of phosphate fertilizer is used year after year, and phosphorus is used at a low rate. Nitrogen and phosphorus are relatively abundant in the soil due to less nitrogen and phosphorus absorbed by plants, nitrogen volatilization, leaching and loss. Insufficient, less nitrogen and phosphorus, a serious imbalance in the proportion of nitrogen as a result of the smallest nutrients.