中文摘要：

灌区排水系统是输出化肥、农药等农业非点源污染物的主要通道。了解排水系统布置与管理对农田氮素运移的影响，对提高作物产量与保护农业生态环境具有重要意义。根据一组灌区排水稻田地下水氮素浓度变化的实测资料，应用经典统计学和地统计学方法，研究田间不同深度地下水中氮素浓度受灌排水系统布置以及水位调控的影响，分析排水稻田地下水中氮素的分布规律。结果显示：两种排水条件下，生长季内田间0.3 m和1.4 m深处地下水中NO-3-N浓度的平均值均随着水稻生长而逐渐减小;常规排水稻田中，0.3 m深处的NO-3-N空间相关性比1.4 m深处强；控制排水使得随机因素对1.4 m深处NO-3-N的空间变异性影响减小;NO-3-N和 NH＋4-N浓度分布并没有随灌排系统布置呈现出有规律的变化。

英文摘要：

Understanding nitrogen migration as influenced by design and management of drainage systems is important for improving crop production and protecting agricultural ecological environment. In this paper, according to the nitrogen concentrations were measured by sampling groundwater in paddy fields through installation of observation wells at different depths, traditional statistics and geostatistical methods were used to study the nitrogen concentration influenced by drainage system and water level control and analyzed nitrogen distribution. The results show that NO3^- - N concentration average is gradually reducing with rice growing at 0.3 m and 1.4 m depths under conventional and controlled drainage. Spatial correlation of NO3 - N at 0.3 m is stronger than that of at 1.4 m by spatial analysis under conventional drainage condition . The spatial distribution of NO[ - N and NH4 - N are not affected by the drainage systems.