Abstract: The dynamic characteristics of phosphorus(P) in surface water of paddy field and its potential environmental impact were studied by the independent irrigation field experiment with different P fertilizer applied rates and two compositions of P application. The results showed that P concentration in surface water were elevated due to P fertilizer application. Both total P and dissolved P reached 0.201-1.301 mg/kg and 0.058-0.926 mg/kg in the first water samples (7 days after P applied) respectively. Under the same P fertilizer applied rate, compared with mineral P fertilizer only, the measurement of integrated supplies mineral fertilizer and organic hog manure could significantly increased P content in surface water. Within the week of first water sampling, the difference of total P concentration between the two compositions of P application was about 3.85-1.89 times, however, this difference decreased with time past and finally reached the same level. Any drainage from paddy field would be considered to induce nearby waters eutrophication. In view of P loss minimizing, P loss potential from surface water in paddy field would be greater when field drainage was conducted in the first week of irrigation after P fertilizer applied or the period of field rake. In addition, P fertilizer should not be applied in the rainy season.

Key words: phosphorus, paddy field, surface water, dynamic, characteristics, environmental impact

摘要： 通过独立排灌式磷肥大田试验探讨了水稻田表水磷素的动态特征及其潜在的环境效应。研究发现, 施入磷肥增加了田表水磷素水平, 首次水样总磷水平为0.201～ 1.301 mg/kg, 溶解磷水平为0.058～ 0.926 mg/kg; 在等量施磷的条件下, 与单施无机磷肥比较, 有机无机磷配施能显著地提高田表水磷素水平; 在首次采样的一周之内, 两者总磷水平相差达3.85～1.89 倍, 但随着时间的推移, 因施磷结构的不同导致田表水磷素水平的差异逐渐缩小并趋于一致。任一次田间排水都存在诱发附近水域水体富营养化的可能。从减少磷素流失的角度出发, 在施磷灌水后约一周之内或田间耘田时, 田间排水磷素流失潜能增大, 另外, 还要避免在雨水集中的季节施用磷肥。

关键词: 磷素, 水稻田, 田表水, 动态, 特征, 环境效应