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土壤磷素的过量流失会危害地表水资源。为了评价农田中磷素释放危险的高潜在性,美国学者提出了耕地磷素流失评价指标。反映了以谷类作物为主的种植体系下,考虑了在侵蚀、径流和亚表层排水等3种主要迁移机制下诸来源因子的多个方面,并估计了进入水体生态系统且转化为对其有效的磷量。当侵蚀危险高时,测得颗粒磷的流失大于可溶性磷的流失,且长期过程明显地大于短期过程。这种磷的评价指标有助于交替选择磷素管理和土壤保护措施,以减少农田向地表水资源迁移的磷总量。
Excessive loss of soil phosphorus can endanger surface water resources. In order to evaluate the high potential of phosphorus release risk in farmland, American scholars proposed the evaluation index of phosphorus loss in arable land. Reflecting the cereal-based cropping system, various aspects of source factors were considered under the three main migration mechanisms of erosion, runoff and subsurface drainage and were estimated to enter the water ecosystem and translate into effective Of phosphorus. When the erosion risk is high, the loss of particulate phosphorus is greater than the loss of soluble phosphorus, and the long-term process is significantly greater than the short-term process. This assessment of phosphorus helps to alternate the selection of phosphorus management and soil conservation measures to reduce the total amount of phosphorus transported from farmland to surface water resources.