The present study employs a process-based DSSAT (Decision Support System for Agrotechnology Transfer) model for estimating agriculture water use and its evaluation for simulating groundwater fluctuations. A field experiment was performed during kharif season with PR 121 variety (rice) at Punjab Agricultural University, Ludhiana. There were six treatments with three dates of transplanting – June 5 (D₁), June 20 (D₂) and July 5 (D₃), one cultivar – PR121 (V) and two irrigation regimes – 2-day drainage (I₁) and tensiometer-based (I₂). Both simulation and experimental results showed that paddy transplanted on June 20 (D₂) and tensiometer-based irrigation treatment (I₂) gave 23 and 32% higher yield in comparison to June 5 (D₁) and July 5 (D₃) with maximum water use efficiency of 1.69 kg/m³. The validated DSSAT model was simulated for a historical time slice (1998–2014) and indicated that 66% of applied water in the form of rainfall or irrigation in paddy fields was lost as drainage component. The simulated change in storage (rainfall minus evapotranspiration) was able to explain groundwater level fluctuations in terms of trends/magnitude in most of the years.

本研究采用基于过程的DSSAT（农业技术转让决策支持系统）模型来估算农业用水量，并对其模型进行评估以模拟地下水波动。在卡里夫季节期间，在卢迪亚纳的旁遮普农业大学对PR 121品种（大米）进行了田间试验。一共有6种处理方法，其中有3种移栽日期– 6月5日（D ₁），6月20日（D ₂）和7月5日（D ₃），一种品种– PR121（V），两种灌溉方式– 2天排水（I ₁）和基于张力计（I ₂）。模拟和实验结果均表明，水稻于6月20日移植（D ₂）和基于张力计的灌溉处理（I ₂）与6月5日（D ₁）和7月5日（D ₃）相比，分别提高了23％和32％的产量，最大用水效率为1.69 kg / m ³。经过验证的DSSAT模型针对一个历史时间段（1998-2014年）进行了仿真，结果表明，稻田中以降雨或灌溉形式施用的66％的水作为排水成分而流失了。模拟的蓄水变化（降雨减去蒸散量）能够解释大多数年份中地下水位的趋势/幅度波动。