There have been many articles published about the dilemma facing growers in the Great Plains when it comes to irrigation. The challenge growers and decision makers face in preserving aquifers for agricultural use, without allowing them to be drained to unsustainable levels, is daunting.
These issues were brought front and center again this week at the Great Plains Irrigation Conference in Burlington, Colo., where researchers from two universities and the federal government filed a 24-page report about the future of irrigation in the Plains states.
Greatly increased irrigation efficiency and recharge from rivers has improved the picture in Nebraska for the High Plains Aquifer, the main source of irrigation water in the region. But the outlook is less positive in western Kansas, eastern Colorado, and the panhandles of Oklahoma and Texas.
“The aquifer in these regions is recharged at rates much less than current pumping, and the aquifer is declining as a result,” the authors say, adding that the Southern High Plains stands to lose 35% of its irrigated land in the next 20 to 30 years at current rates of depletion.
Researchers note that improved irrigationmanagement technology and adoption of notill practices have helped improve water-use efficiency. Some 54% of the increases in grain sorghum yield in recent decades can be attributed to adoption of reduced tillage and no-till practices that allowed for improved soil water content at planting time.
Advanced technology — such as subsurface drip and variable-rate irrigation — and better cultivars that improve wateruse efficiency will go a long way toward making irrigation more sustainable, but the researchers believe policies and regulations will also be needed that limit pumping to sustainable levels. Some state and local water boards have already been dealing with these tough decisions.
With historic droughts hitting many of these regions already facing a water shortage, it’s obvious that pumping more irrigation water isn’t a viable solution. We hope that increased adoption of no-till systems that increase soil organic matter and water-holding capacity can help many growers work through the lower allotments of water they’re getting.
In our next edition of Dryland No-Tiller, we’ll share an in-depth feature story detailing how growers are using cutting-edge precision irrigation technology and reduced tillage to improve irrigation efficiency. Stay tuned.