Alternate wetting and drying (AWD) practice in rice cultivation can save a significant amount of irrigation water compared to conventional practice. This practice involves a soil moisture stress-based irrigation scheduling and possibly affects the nitrogen transport in the farm fields. In this study, non-weighing lysimeter plots were used to understand the nitrogen transformation, transport and balance of rice soil under AWD practice. The lysimeter data sets were used to simulate the nitrogen transport for no soil moisture stress (NS: 0 cm), mild soil moisture stress (MS: 450 cm) and severe soil moisture stress (SS: 700 cm)-based irrigation scheduling by using Hydrus-1D model. The Hydrus-1D model was able to simulate N transport (\({NH}_{4}^{+}-N\) and \({NO}_{3}^{-}-N\)) from the ponding water to the soil–plant system for both calibration and validation datasets. The simulation results indicated that the applied N was mostly concentrated within the puddled (top) layer but slightly decreased with the increase in the soil moisture stress. The N crop uptake and leaching loss were decreased by 6% and 38%, in MS and by 15% and 52% in SS, respectively, when compared to NS (flooded rice). Both volatilization and denitrification losses were increased by 14 and 7% in MS, and by 17 and 7% in SS, respectively, when compared to NS. The Hydrus model can be used as a management tool to determine the appropriate soil moisture stress in the puddled layer for which the required N nutrients are sufficiently available to the rice crop and the N loss to the environment can be controlled.

与常规做法相比，水稻种植中的交替湿润和干燥（AWD）做法可以节省大量灌溉用水。这种做法涉及基于土壤水分压力的灌溉计划，并可能影响农田中的氮素运输。在这项研究中，使用非称重测渗仪图了解了AWD方式下水稻土的氮转化，运移和平衡。使用渗漏测定仪数据集，通过使用以下方法模拟了基于无土壤水分胁迫（NS：0厘米），中等土壤水分胁迫（MS：450厘米）和严重土壤水分胁迫（SS：700厘米）的灌溉计划下的氮素运移Hydrus-1D模型。Hydrus-1D模型能够模拟N传输（\（{NH} _ {4} ^ {+}-N \）和\（{NO} _ {3} ^ {-}-N \）），从池塘水到土壤-植物系统，以进行校准和验证数据集。模拟结果表明，施氮量主要集中在水化（顶层）层中，但随着土壤水分胁迫的增加而略有降低。与NS（水淹稻）相比，MS的氮素吸收量和淋溶损失分别降低了6％和38％，而SS分别降低了15％和52％。与NS相比，MS的挥发损失和反硝化损失分别增加了14％和7％，SS分别增加了17％和7％。Hydrus模型可以用作管理工具来确定水化层中合适的土壤水分胁迫，为此，所需的N营养素可充分用于水稻作物，并且可以控制N对环境的损失。