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榆垡乡地处北京市南郊,位于大兴县西南部,西靠永定河,北滨天堂河.地势低洼,地下水位较高,属华北冲积平原.成土母质为河流冲积物.0—20公分土壤含石灰质较高,含碳酸钙平均为15.3%.磷肥施入以后极易生成不溶性的磷酸钙盐.从而降低了磷肥的施用效果.1977年我们进行试验,施入磷肥以前,速效磷是4ppm.每亩施40千克磷肥以后,第二天测定速效磷是40ppm.施后
Elm Township is located in the southern suburbs of Beijing, located in the southwest of Daxing County, west of Yongding River, North Beach Paradise River. Low-lying, high groundwater level, belong to the North China alluvial plain soil parent material for the river alluvial .0-20 cm Soil containing lime is higher, containing an average of 15.3% of calcium carbonate. Phosphate fertilizer into the very easy to generate insoluble calcium phosphate, thereby reducing the application of phosphate fertilizer .1977 we test, before the application of phosphate fertilizer, available phosphorus is 4ppm After applying 40 kg of phosphate fertilizer per mu, the available phosphorus was determined to be 40 ppm on the following day