A robust soil-water system is essential for achieving most of the Sustainable Development Goals of United Nations. Systems approach is essential to keep the soil-water system to derive sustainable benefits. Prevention is better than cure; hence accurate prediction of the likely results of our action on soil-water system is needed. Hydrus is one of the handy tools for simulating root zone under drip irrigation to derive best management practices for water and nutrient application. Hydrus is parameter intensive software. Hence, mostly, there is a tendency to use typical values of parameters available in the literature for modelling. In this research work, we generated data for Hydrus by intensive field experimentation to improve the reliability of modelling. The first order rate constants of urea-ammonium-nitrate reactions were obtained by field experimentation. HYDRUS was used numerically to simulate nitrogen transport for paddy crop under drip irrigation. From the simulation, various fluxes of urea, ammonium and nitrate were quantified, to develop a N fertigation schedule for entire crop duration. The fertigation schedule was implemented by raising a paddy crop and evaluation was done by estimating N assimilation of crop by plant sample analysis. The simulated values of nitrogen uptake were in good agreement with the observed values of nitrogen uptake.

健全的土壤-水系统对于实现联合国的大多数可持续发展目标至关重要。系统方法对于保持土壤-水系统获得可持续利益至关重要。预防胜于治疗; 因此，需要准确预测我们对土壤-水系统采取行动的可能结果。Hydrus是在滴灌条件下模拟根区以获取水和养分施用最佳管理方法的便捷工具之一。Hydrus是参数密集型软件。因此，大多数情况下，倾向于使用文献中可用参数的典型值进行建模。在这项研究工作中，我们通过密集的现场实验为Hydrus生成了数据，以提高建模的可靠性。通过野外实验获得了尿素-硝酸铵反应的一级速率常数。使用HYDRUS数值模拟滴灌条件下稻田作物的氮素运移。通过模拟，对尿素，铵和硝酸盐的各种通量进行了定量，以制定整个作物持续期的氮肥施肥计划。施肥计划是通过种植水稻作物来实现的，而评估则是通过植物样品分析来估计作物对氮的吸收。氮吸收的模拟值与氮吸收的观测值非常吻合。为整个作物持续时间制定氮肥施肥计划。施肥计划是通过种植水稻作物来实现的，而评估则是通过植物样品分析来估计作物对氮的吸收。氮吸收的模拟值与氮吸收的观测值非常吻合。为整个作物持续时间制定氮肥施肥计划。施肥计划是通过种植水稻作物来实现的，而评估则是通过植物样品分析来估计作物对氮的吸收。氮吸收的模拟值与氮吸收的观测值非常吻合。