Projection of the Irrigation Water Requirement of Forage Corn Under Climate-Change Conditions in the North of Mexico

Climate change has put the agricultural industry under enormous pressure, as rising temperatures and changing rainfall patterns are affecting crop yields and productivity. The temporal variability of the irrigation water requirement (IWR) as a function of crop evapotranspiration (ETc) and effective rainfall (Peff) was analyzed for forage corn cultivation from a climate-change perspective in the “Comarca Lagunera” region, located in the north of Mexico. The time periods 1975–2016 and 2061–2080 were analyzed, the latter using the forcings of the climate-change scenario SSP5-8.5, from the meteorological data. The Peff, ETc, and IWR for the maize crop were modeled with CROPWAT software, and the Rodionov test was applied to detect points of change in the three variables mentioned above. The historical values of IWR, ETc, and Peff values for spring were estimated at 511, 571, and 57, while for summer, they were 336, 450, and 122, respectively. The climate-change scenario toward the distant horizon projects increases in IWR of 11.9% and 3.5% and in ETc of 7.7% and 0.6%, respectively, for both spring and summer agricultural cycles, as well as decreases in Peff of −30% and −12%, respectively. These results emphasize the combined impact of rising temperatures and reduced rainfall on crop water needs, a crucial factor for crop production in regions that depend on agricultural irrigation. This study provides a foundation for planning irrigation water management in anticipation of an imminent increase in demand due to erratic weather patterns in arid zones.