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淡灰钙土是宁夏重点开发利用的耕地资源。针对新垦淡灰钙土土壤速效P含量贫乏的问题,采取田间定位试验的方法,研究了新垦淡灰钙土4年的玉米施磷效应,结果表明:新垦淡灰钙土施用磷肥不但当季玉米增产效果显著,而且连续3年磷肥残效也十分显著,随着施磷量的增加,后效也增大。同时,增施磷肥可迅速提高土壤速效P含量,P2O5施用量为138.0、207.0、279.0、414.0kghm-2,当季土壤速效P含量较不施磷肥增加1.8mgkg-1～10.4mgkg-1,提高90%～520%。但在第2年～第4年不施磷肥的情况下,土壤速效P含量明显下降。
Light gray earth is the focus of development and utilization of cultivated land resources in Ningxia. In order to solve the problem of poor P content in the newly reclaimed lightly calcareous soils, a field experiment was conducted to study the four-year application of P fertilizers. The results showed that the application of P fertilizers not only Seasonal corn yield increase effect is remarkable, and for 3 consecutive years of phosphorus residue is also very significant, with the increase of phosphorus, after-effects also increased. At the same time, the available P content of soil increased rapidly with the increase of P fertilizer, and the P2O5 application rate was 138.0,207.0,279.0,414.0kghm-2. The available P content in soil increased 1.8mgkg-1 ~ 10.4mgkg-1 90% ~ 520%. However, in the second year to the fourth year without phosphate fertilizer, soil available P content decreased significantly.