A simulation study based on water balance approach and field experimentation with rice-wheat cropping system was carried out by employing daily rainfall and evaporation (2002–2016) and edaphic data of Experimental Farm of the university, Pusa (25.98°N, 85.67°E, 52 m amsl), Bihar, situated under middle Indo-Gangetic Plains. The aims of the study were to optimize transplanting dates and assess irrigation requirement and water productivity of rice with a view to achieve climate smart rice-wheat production system. The suitability of advancing wheat planting under this cropping system was also evaluated for escaping terminal heat stress during reproductive to maturity period. Under rice-wheat system, late transplanting of rice during kharif season (monsoon season, synonymously also called as wet season) and, consequently, late planting of wheat during rabi (winter) season tend to reduce grain yield significantly under a set of adverse environmental conditions during flowering to maturity phases of both the crops. The study revealed that rice crop of 150-day duration (seed to seed) could be successfully transplanted early in the kharif season during 20–30 June and be harvested by 25 October–5 November with the use of average 404–425-mm irrigation water to achieve potential yield and higher water productivity (1.648–1.731 kg m⁻³ ha⁻¹). Early rice harvesting ensured early completion of wheat planting before 15 November, which helped in escaping terminal high-temperature stress during the reproductive phase. Hence, higher system productivity can be achieved by shifting the planting dates of rice and wheat through optimum utilization of natural resource environment (moisture and thermal regimes) and offsetting the negative impacts of erratic monsoon rains on rice growth and terminal heat stress and hailstorm on subsequent wheat crop.

利用每日降雨和蒸发量（2002-2016年）以及普萨大学实验农场（25.98°N，85.67°E）的水文资料，基于水平衡方法和稻麦种植系统的田间试验进行了模拟研究。 ，52 m amsl），比哈尔省（Bihar），位于印度－恒河中部平原之下。该研究的目的是优化移栽日期并评估水稻的灌溉需求和水生产率，以实现气候智能型稻麦生产系统。还评估了在这种耕作制度下促进小麦种植的适宜性，从而避免了生育期到成熟期的终极热胁迫。在稻麦系统下，在哈里夫期间晚稻的移栽季风（季风季节，也称为湿季），因此，在两种作物的开花期至成熟期的一系列不利环境条件下，在狂犬病（冬季）季节晚播小麦往往会显着降低谷物产量。研究表明，持续150天的水稻作物（种子）可以在6月20日至30日的哈里夫季节早期成功移植，并在10月25日至11月5日收获，平均使用404-425毫米灌溉水以实现潜在的产量和更高的水生产率（1.648–1.731 kg m ^-3  ha ^-1）。早稻收割确保了11月15日之前小麦播种的早日完成，这有助于避免生育期终末的高温胁迫。因此，通过最佳利用自然资源环境（水分和热力状况）来改变水稻和小麦的播种日期，并抵消季风雨季降雨对水稻生长和终末高温胁迫以及冰雹的不利影响，可以提高系统的生产力。小麦作物。