苕溪流域不同施肥条件下稻田田面水氮磷动态特征及产量研究

本研究设计了不同肥料和不同施肥管理方式等8种处理，以期通过研究不同减量施肥处理下稻田田面水中氮素和磷素的动态变化来了解研究区面源污染状况及风险。结果表明，各减量化处理均能有效保证水稻产量，同时不同程度降低了田面水中的氮磷浓度，降低流失潜能。总氮和铵氮分别在施肥后第1天和第3天达到峰值，一周之后降至较低水平，铵氮是田面水中氮素流失预防的主要监测对象。总磷和可溶态磷均在施肥后第1天便达到峰值，之后迅速降低至稳定，5天后总磷浓度降至1 mg/L以下，可溶态磷/总磷基本在0.5以下，田面水中磷素的主要流失形态为悬浮颗粒态磷。此外，后期的施氮行为会引起田面水中可溶态磷/总磷的上升，使可溶态磷相对流失潜能增大。

Study on Rice Yield and Dynamics of Nitrogen and Phosphorus in Surface Water of Paddy Field Under Different Fertilizations in Tiaoxi River Basin

Under 8 treatments with different fertilization and management practices, this study investigated the status and risk of non-point pollution in Tiaoxi River basin through the dynamic of N and P in surface water of paddy field. The results showed that all of fertilizer reduction treatments could ensure the rice yield and reduce the concentration and loss potential of N and P in surface water of paddy field. The highest concentrations of TN and NH4+-N occurred at the 1st and 3rd day after fertilization, and descended to a low level in 7 days after fertilization. NH4+-N was the main monitoring indicator of N loss in paddy field. The highest concentrations of TP and DIP occurred at the 1st day after fertilizations, and decreased with time. The concentration of TP descended to less than 1 mg/L in 5 days after fertilization. DIP/TP was basically less than 0.5, suggesting the suspended particulate phosphorus was the main way of P loss. In addition, the later fertilization could increase the relative loss potential of DIP by raising the value of DIP/TP.