中文摘要：

南太湖区域内稻田磷素的流失浓度及负荷与田间水浆管理技术密切相关.本研究在南太湖区域农业生态与植物保护监测站（余杭区）建立中长期试验基地,重点探索稻田养分管理技术-节水灌溉模式-降水资源高效利用的组合技术控制下水田磷素流失的过程及其截流机制.结果表明,不同的磷肥施用水平下田表水磷素浓度随时间的降低而降低,随之趋于背景含量水平.传统灌溉总磷负荷为0.046～3.569kg·hm-2,节水灌溉总磷负荷为0.023～2.602kg·hm-2,传统灌溉比节水灌溉具有更高的磷素流失风险.本次试验提出了稻田水分“零排放”的技术模式,实现了传统灌溉总磷净负荷-0.102 kg·hm-2,节水灌溉总磷净负荷为-0.078 kg·hm-2,传统灌溉的截流磷素量高于节水灌溉模式.在无排水的前提下,稻田在P循环的“源-汇”交替中扮演“汇”的角色,实现了稻田圈截流磷素的生态作用.考虑多变的天气情况,节水灌溉模式在截流磷素方面将发挥更大的作用,可有效地使稻田向太湖的年磷素输出量最小化.

英文摘要：

A field experiment to elucidate the interception of phosphorus （P） export during a typical rice-growing season was conducted in the southern region of the Taihu Basin in China. Phosphorus export was measured for both traditional and water-saving irrigation-drainage regimes after application of superphosphate. P concentrations in floodwater rapidly declined after the application of P fertilizer, and subsequently returned to the background levels. The traditional irrigation-drainage scheme and the water-saving irrigation-drainage method contributed Total Phosphorus （TP） loads ranging from 0. 046 to 3. 569 kg· hm^-2, and 0. 023 to 2. 602 kg· hm^-2, respectively. Clearly the traditional irrigation-drainage practice had higher risk of P losses than the water-saving irrigation-drainage practice. An innovative water management scheme called ＂zero-drainage＂ technology was developed in this experiment. The net TP loads under the water-saving irrigation-drainage regime were - 0. 078 kg· hm^-2, but they were - 0. 102 kg· hm^-2 under the traditional irrigation-drainage regime. The paddy field could intercept P losses by acting as a pollutant sink rather than a source. The innovative water-saving irrigation-drainage technology should be applied full-scale to minimize P export.