Modelling the Effect of Environmental Conditions on Wheat Yield in Gujarat Using APSIM-Wheat Model

Abstract

Wheat (Triticum aestivum L.) is a major staple crop globally and a key contributor to food and nutritional security in India. The area, production, and productivity of wheat in India have increased significantly due to the introduction of high-yielding varieties during the Green Revolution. Climate change-induced variations in temperature, radiation, and atmospheric CO₂ concentration are expected to significantly influence wheat productivity. The study aims to effect of change in environmental conditions on wheat grain yield using the APSIM wheat model. A sensitivity analysis was conducted using the APSIM-Wheat model to quantify the effects of changes in maximum temperature (Tmax), minimum temperature (Tmin), bright sunshine hours (BSS), and CO₂ levels on the grain yield of three wheat varieties, GW 496, GW 451 and GW 513, under the climatic conditions of Anand, Gujarat. Simulation results indicated that increasing Tmax had a substantial negative impact on yield, with a +5°C rise reducing grain yield by 19.5-23.1%, whereas a −5°C decrease enhanced yields by up to 19.2%. Similarly, elevated Tmin reduced productivity, with GW 496 showing the highest loss (-27.3% at +5°C), while lower Tmin values improved yields by up to 10.9%. Among the varieties, GW 496 exhibited the greatest sensitivity to temperature fluctuations, while all varieties responded positively to increased BSS and CO₂ enrichment. These findings emphasise the dual challenge and opportunity posed by climate change-while rising temperatures threaten yield stability, strategic management of sowing dates, irrigation, and cultivar selection, combined with the potential benefits of CO₂ fertilisation, could help sustain wheat production. This study provides valuable insights for climate-resilient agricultural planning and underscores the importance of integrating crop simulation modelling into policy and farm-level decision-making to ensure long-term wheat productivity under changing environmental conditions. Overall, the findings emphasise that wheat production in Anand is particularly vulnerable to an increase in temperature and a reduction in sunshine hours, but could benefit from elevated atmospheric CO2 levels, provided other growth factors remain optimal.