The advent of pivot irrigation helped turn much of the arid High Plains green with crops, but a multi-disciplinary study from Kansas State University indicates that current levels of water use for crop and livestock production in the region cannot be sustained indefinitely. Cutting back now, the researchers say, would reduce production in the short term but could extend the lifetime of the aquifer and increase net production.
The study, published in the Proceedings of the National Academy of Sciences, involved researchers from the departments of Civil Engineering, Agronomy and Clinical Sciences (Mike Apley, DVM, PhD) at Kansas State and the Department of Environmental Science and Engineering, Fudan University, Shanghai, China.
The authors note the High Plains Aquifer supplies 30 percent of the nation’s irrigated groundwater, and the Kansas portion supports the congressional district with the highest market value for agriculture in the nation.
However, research indicates agriculture has pumped out 30 percent of the groundwater from that aquifer and at current irrigation trendlines would remove another 39 percent over the next 50 years.
Recharging of the aquifer accounts for only about 15 percent of the current use, and it would take about an 80 percent reduction in pumping to reach equilibrium with recharge rates. However, the researchers note that ongoing improvements in water-use efficiency in corn production could allow agricultural production on irrigated land to increase through 2040 with somewhat lower water use.