Jiao Ping-Jin, Xu Di, Zhu Jian-Qiang, Yu Ying-Duo
National Center for Efficient Irrigation Engineering and Technology Research, Beijing 100048, China.
State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.
Huan Jing Ke Xue. 2016 Oct 8;37(10):3842-3849. doi: 10.13227/j.hjkx.2016.10.023.
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.
考虑到循环灌溉在提高降雨利用效率和减少农业面源污染方面的潜力，开展了排水循环灌溉稻田磷素运移试验，以解决中国南方磷素流失污染问题以及降雨时间分布与作物需求不匹配的问题。利用莲藕塘水和鱼塘水灌溉稻田，监测地表水和渗滤液中总磷（TP）、溶解态磷（DP）和溶解性反应磷（DRP）的浓度，以及土壤剖面总磷和有效磷（Olsen-P）浓度。结果表明，在排水循环灌溉条件下，地表水和渗滤液中TP、DP和DRP的浓度沿田块方向降低，尤其是渗滤液中的磷浓度下降更为明显。由于循环灌溉水源的磷含量在一定范围内变化，地表水和渗滤液中的磷浓度并未升高。地表水和渗滤液中TP、DP和DRP的浓度随循环灌溉时间而变化，8月份磷浓度最低。表层土壤有效磷（Olsen-P）浓度沿田块方向降低，并随循环灌溉水源磷含量的增加而升高，土壤剖面总磷浓度不受循环灌溉影响。延长田块长度或在8月份进行循环灌溉可提高稻田的磷去除率。
