• 关键词：水稻田  氮素  动态特征  模式表征  流失

• 基金项目：浙江省科委项目(971103195);省科技计划项目(992030)

• 张志剑
• 浙江大学环境与资源学院,杭州 310029

• 董亮
• 浙江大学环境与资源学院,杭州 310029

• 朱荫湄
• 浙江大学环境与资源学院,杭州 310029

• 摘要：采用具有独立排灌系统的田间试验研究了水稻田面水氮素的动态特征、模式表征及田间排水氮素流失.施用尿素后,田面水氨氮、总氮浓度迅速增加;随时间的推移,田面水氮素浓度下降较快.施氮后第3-4天,田面水氨氮总氮比为0.41-0.91,随时间的推移,氨氮总氮比呈下降趋势.田面水总氮、氨氮浓度随时间动态下降的最佳拟合模式为指数、对数或乘幂型.在控水灌溉下的水稻田,两次田间排水合计总氮流失负荷分别为8.993-29.131kghm²,氮肥表观流失率随施氮量提高而逐渐下降.施氮后一周是防止水稻田面水

• Abstract：A field case study with independent irrigation system was conducted to elucidate the dynamic characteristics, modeling of nitrogen (N) in surface water of paddy field and N loss from drainage. The results of field experiment showed that urea application within three times sharply increased the concentrations of ammonia nitrogen (NH₄⁺-N) and total nitrogen (T-N) in field surface water and both subsequently declined as the time followed.On the third to fourth day after N application the rate of NH₄⁺-N/T N in surface water was 0.41-0.91, and slowed down as the time followed. Quantitative models with best coefficient for T N and NH 4 N concentrations in the field surface water after N fertilizer application were exponential and logarithmic or logarithm.Total N loss within two drainages reached 8.993kg N/hm² (N-Ⅰ), 16.013kg N/hm² (N-Ⅱ), 24.969kg N/hm² (N-Ⅲ), 26.744kg N/hm² (N-Ⅳ) and 29.131kg N/hm² (N-Ⅴ) respectively.It was clear that N apparent loss ratio was reduced as the N applicated level increased. The period within a week after N application was defined as the key time to control massive N loss from flooded paddy field. To control N nonpoint pollution from paddy field, further research must be focused on the minimization of N loss from paddy field drainage and the best N management for native rice production.

• Key words：Paddy field  nitrogen  dynamic characteristic  modeling  loss

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