| 排水循环灌溉下稻田磷素时空分布特征 |
| 摘要点击 1368 全文点击 802 投稿时间：2016-01-28 修订日期：2016-03-16 |
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| 中文关键词 循环灌溉 磷流失 稻田 渗漏 排水 田面水 |
| 英文关键词 cyclic irrigation phosphorus loss paddy leaching drainage surface water |
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| 中文摘要 |
| 排水循环灌溉具有提高降水资源利用率和减少农田面源污染的潜力，为缓解我国南方地区降雨分布与水稻作物需水时间不匹配和农田磷流失污染的问题，开展了排水循环灌溉条件下稻田磷素时空分布规律研究. 采用田间试验的方法，监测藕塘水和鱼塘水循环灌溉下水稻田面水和渗漏水中总磷、可溶性磷和可溶性反应磷的质量浓度，及土壤剖面总磷与Olsen-P含量的变化. 结果表明，排水循环灌溉下水稻田面水和渗漏水中不同形态磷素质量浓度沿程降低，尤其渗漏水磷质量浓度的减少趋势更为显著，排水循环灌溉水源中磷质量浓度在一定范围内的变化不会增加田面水和渗漏水中的磷质量浓度. 田面水和渗漏水中不同形态磷质量浓度在不同灌溉时期的变化较大，8月田面水和渗漏水的磷质量浓度明显低于其它时期. 表土Olsen-P含量随距进水口的距离的增加而减少，并随排水循环灌溉水中磷质量浓度的增加而增加；土壤剖面TP含量受排水循环灌溉的影响不明显. 在8月水稻需肥高峰期进行排水循环灌溉或延长灌溉水的流程，可明显改善排水循环灌溉下稻田的磷素去除效率. |
| 英文摘要 |
| Considering the potential of cyclic irrigation to increase rainfall use efficiency and reduce agricultural non-point pollution, the experiment of phosphorus transport in paddy fields under cyclic irrigation of drainage water was conducted to address the problem of phosphorus loss pollution and the mismatch between rainfall temporal distribution and crop requirement in the south of China. Lotus pond water and fishpond water were used to irrigate paddy fields for monitoring concentrations of total phosphorus (TP), dissolved phosphorus (DP), and dissolved reactive phosphorus (DRP) in surface water and leachate, and soil profile total phosphorus and Olsen-P concentrations. The results showed that the concentrations of TP, DP and DRP in surface water and leachate decreased along the field under cyclic irrigation of drainage water, especially the phosphorus concentrations of leachate dropped more obviously. As the phosphorus content of cyclic irrigation water sources varied within a certain range, phosphorus concentrations of surface water and leachate did not increased. The concentrations of TP, DP and DRP in surface water and leachate varied with cyclic irrigation time, and the least phosphorus concentrations were observed in August. Top soil Olsen-P concentration decreased along the field and increased with phosphorus content of cyclic irrigation water sources, and soil profile TP concentration was not influenced by cyclic irrigation. Phosphorus removal ratio of paddy field could be increased by extending field length or cyclic irrigation in August. |
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