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根据2008年耕地地力评价结果,及与1982年第2次土壤普查时土壤有机质、全氮、有效磷、速效钾含量的比较,杭州市余杭区土壤各项养分平均含量均有所增加。其中低山丘陵区速效钾含量增幅最大;河谷平原区全氮含量增幅最大;水网平原区和滨海平原区有效磷含量增幅最大;有机质含量增加主要是由农作物秸秆还田所贡献;全氮含量提高主要是氮化肥大量施用和秸秆还田所致;有效磷及速效钾含量增加主要是由于磷化肥及复合肥大量施用的结果。
According to the evaluation results of cultivated land productivity in 2008 and the contents of soil organic matter, total nitrogen, available phosphorus and available potassium in the second soil census in 1982, the average contents of nutrients in Yuhang District of Hangzhou increased. Among them, the content of available potassium in the hilly region increased most rapidly; the content of total nitrogen increased most significantly in the plain of the river; the content of available phosphorus increased most obviously in the water plain and the coastal plain; the content of organic matter was mainly contributed by crop straw returning; Mainly due to the application of nitrogen fertilizer in large quantities and straw returning; the increase of available phosphorus and available potassium is mainly due to the large amount of application of phosphate fertilizer and compound fertilizer.