中文摘要：

借助自行设计的直管型和弯管型渗漏计,研究水稻生长期间不同施氮水平下稻田犁底层渗漏水中铵态氮和硝态氮的动态变化,以探寻氮素的渗漏损失规律;利用系统动力学模拟软件Vensim构建氮素转化、循环模型,模拟了氮素在水稻、土壤和水中的迁移转化过程,用2003年杭州余杭区稻田0、75、150、225、300、375kg N·hm^-2氮素水平试验结果来校准模型系数,并用2007年相同氮素水平下试验田大田数据来验证模型.从稻田不同供氮水平分次施肥后渗漏水中氮浓度的模拟结果与实测值的比较可知,直管和弯管型渗漏计的模拟数据与实测值的拟合程度较好,说明模型模拟结果可靠,具有应用价值.

英文摘要：

By using self-designed lysimeters, the dynamic changes of ammonia- and nitrate N leakage from the plowpan of paddy field under different N supply were studied, aimed to understand the N leakage loss from paddy field during rice growth period. A dynamic model was built to simulate the N translocation and transformation in rice plant, soil, and water by Vensim software. The data from the field experiment with N fertilization rates of 0, 75, 150, 225, 300, and 375 kg· hm^-2 in Yuhang district, Hangzhou City in 2003 were used for calibrating the model, and the data from the field experiment in 2007 were utilized for validating the model. The simulated N concentrations in the leakage fitted well with the observed data, suggesting that the simulated results were reliable and the model was applicable.