April 29, 2024

Climate Change and U.S. Agriculture: Why Irrigating More Crops Is Vital for Future Yield

Expenses and Economic Analysis
Installing, keeping, and running watering equipment comes at a substantial expense to farmers, as much as $160 per acre annually. “Our work basically produces a U.S. map of where it will make the a lot of sense to set up and utilize irrigation equipment for corn and soybean crops in the future,” states initially author Trevor Partridge, a Mendenhall Postdoctoral Fellow and research hydrologist with the U.S. Geological Survey Water Resources Mission Area, who performed the research study while working on his PhD at Dartmouth.
U.S. map of predicted mid-century watering groundwater deficit– the volumetric distinction between irrigated water and available water– with currently irrigated corn and soybean areas outlined in black. The increasing costs of drought are pressing farmers to invest in watering throughout regions of the Corn Belt and southeastern U.S., and the long-lasting financial return on these financial investments is tough to predict.
Approach and Climate Scenarios
To conduct the cost-benefit analysis of irrigating corn and soybeans, the researchers ran a series of crop model simulations. They applied a number of international environment forecasts that cover the variety of possible future environments– dry and hot, hot and damp, cool and dry, cool and wet, each relative to the average environment projection– to mimic future crop development under totally irrigated or rainfed conditions.
For each climate situation, the crop model was run for both corn and soybeans across all cultivated areas in the U.S. The crop design simulations analyzed 3 periods: historical (1981-2010), mid-century (2036-2065), and end-of-century (2071-2100) under moderate and high greenhouse gas emissions scenarios. The simulations factored in county-level crop management and growth information from the U.S. Department of Agriculture National Agricultural Statistical Service, consisting of maturity, harvest, and planting dates.
Economic Benefits and Water Deficit
To determine the financial advantages of watering– the group computed the extra simulated crop yield from watering and the corresponding increased market price that could be expected– relative to the watering expenses, which included the electrical energy required to pump groundwater and disperse it over the field, and associated costs per acre to own and operate the irrigation system.
The team examined not just where and when it makes good sense to set up watering for corn and soybeans but also if there will be adequate water to do so. They determined the “irrigation water deficit,” which is the basic distinction in between just how much water is applied to the field relative to just how much water should be readily available for irrigation.
Outcomes and Water Availability
The outcomes show that by mid-century there will likely suffice water to irrigate soybeans in Iowa, Wisconsin, Ohio, and northern Illinois and Indiana, but not corn. Iowa is the biggest producer of corn in the U.S. Groundwater resources for irrigation were found to be the most abundant in the southeast U.S., specifically in the lower Mississippi Valley where agriculture is less intensive. Nevertheless, in this region the advantages of watering are minimal.
” Our results recommend that there is relatively little overlap between where there is enough water to completely water crops without placing additional stress on water resources and where farmers can anticipate the investment in watering to spend for itself over the long term,” states Partridge.
Obstacles and Environmental Stress
For example, the Ogallala Aquifer in the Great Plains is the biggest aquifer in the U.S., offering water to eight states, and supports one the most thoroughly irrigated areas for corn and soybeans.
” The increasing benefits of irrigation, could incentivize farmers to use more water, which will put extra stress on crucial aquifers, including the Ogallala,” says senior author Jonathan Winter, an associate professor of location and lead of the Applied Hydroclimatology Group at Dartmouth. Prior research study has shown that water is being extracted from the Ogallala Aquifer much faster than it can be replenished. “Theres simply inadequate water to continue watering at the existing rate from the Ogallala, specifically in the southern portion where groundwater levels are rapidly falling,” states Winter.
Future Implications
With greater warming, such as end-of-century under a high greenhouse gas emissions situation, heat tension will control influence on crop yields and minimize the effectiveness of watering as an adaptation technique throughout the majority of the U.S., particularly for corn. Corn generally has a greater yield than soybean, but soybeans are more heat tolerant, do not need as much water, and have a somewhat much shorter growing season.
” By the end of the century, our simulations suggest that it will be more economically advantageous to irrigate soybeans than corn,” states Winter. “Once irrigation is installed, we could see some locations that historically grew corn switch to soybeans since its a low-priced adaptation.”
When it comes to watering, farmers need to consider a series of complex and contending aspects: previous yield performance, crop market price, energy costs, financial rewards, and seasonal weather condition forecasts. The scientists hope that their analysis can be utilized to assist agricultural and water resource management policies in adjusting to a warmer climate.
Reference: “Irrigation advantages surpass costs in more United States croplands by mid-century” 14 August 2023, Communications Earth & & Environment.DOI: 10.1038/ s43247-023-00889-0.
Anthony Kendall and Bruno Basso at Michigan State University, Lisi Pei at Michigan State University and Georgia Institute of Technology, and David Hyndman at the University of Texas at Dallas also contributed to the research study.

U.S. map of projected change in crop watering worth for corn and soybeans by the middle of the 21st century with presently irrigated areas detailed in black. Credit: Trevor Partridge et al
. Scientist perform a cost-benefit analysis of broadened watering of corn and soybeans under future climate.
With climate modification, watering more crops in the United States will be vital to sustaining future yields, as drought conditions are likely to increase due to warmer temperatures and shifting rainfall patterns. Less than 20% of croplands are equipped for irrigation.
The Benefits of Expanded Irrigation
The outcomes show that by mid-century corn and soybeans that are presently rainfed would benefit from irrigation in many of North Dakota, eastern South Dakota, western Minnesota, Wisconsin, and Michigan. Soybean farmland that relies on rain throughout parts of Indiana, Illinois, Ohio, Kentucky, Kansas, and Oklahoma would likewise benefit from irrigation.

U.S. map of forecasted change in crop watering worth for corn and soybeans by the middle of the 21st century with currently irrigated areas outlined in black. Researchers conduct a cost-benefit analysis of broadened watering of corn and soybeans under future environment.
The outcomes show that by mid-century corn and soybeans that are presently rainfed would benefit from irrigation in most of North Dakota, eastern South Dakota, western Minnesota, Wisconsin, and Michigan. U.S. map of predicted mid-century irrigation groundwater deficit– the volumetric distinction in between irrigated water and offered water– with currently irrigated corn and soybean areas detailed in black. Iowa is the largest producer of corn in the U.S. Groundwater resources for irrigation were discovered to be the most abundant in the southeast U.S., particularly in the lower Mississippi Valley where farming is less intensive.