Arkansas ranks fifth nationwide when it comes to withdrawing water, according to a report recently produced by the United States Geological Survey. This report also ranked Arkansas third overall for irrigation withdrawals. Altogether, Arkansas uses roughly 4% of the nation’s annual water, which is significant considering that it is the 33rd most-populous state in the country. The majority of Arkansas’ water consumption comes from irrigating crops primarily in the eastern portion of the state where most of the state’s crops are produced.
Arkansas is a state that has been blessed with an abundance of natural resources, water being one of them. Thus, it is important for Arkansas operators and landowners to recognize that our valuable aquifers are being depleted, and sustainable irrigation practices should be implemented to help preserve the State’s groundwater. The University of Arkansas Division of Agriculture (UA) has recognized several forms of sustainable irrigation technology and practices to help farmers select a method that best applies to their operations.
Computerized Hole Selection (CHS) is a computer software application that can be implemented to evaluate furrow irrigation systems. These systems incorporate row lengths, field elevations, pipe elevations, flow rates, pressure and friction loss to calculate the proper holes to punch in poly-pipe, allowing a uniform application of water. This software can even be used in rice production to flood each bay between levees simultaneously, known as multiple inlet irrigation. Such uniform application of water throughout a field means a reduction of run-off, which ultimately leads to more efficient irrigation and water withdrawal. According to the UA, using Computerized Hole Selection systems can potentially reduce water usage and irrigation costs by 25% or more. Pipe Hole and Universal Crown Elevation Tool (PHAUCET) and Pipe Planner by Delta Plastics are two free CHS systems that producers may utilize to help regulate irrigation costs and water use.
Irrigation scheduling is another sustainable method recognized by the UA and consists of the determination of the timing and duration of irrigation, the amount of water needed for the crop and the soil water storage capacity to implement an efficient irrigation system. This method eliminates excessive water discharge and leads to a reduction in run-off water by utilizing soil moisture sensors and along with predetermined information about the specific location.
Surge irrigation is another option for controlling excessive water discharge with computerized and mechanized methods. By utilizing surge valves, small amounts of water are discharged down a furrow at once. When released in small surges, the water moves down the rows faster than it would in a conventional constant-flow system. These surge systems have the potential to reduce water use by 20-30%.
There are other technologies and management practices that reduce groundwater use and run-off, but those mentioned above are the easiest and most cost-effective to implement. More information regarding these and other sustainable irrigation methods can be found by visiting the UA Cooperative Extension Service online at www.uaex.edu and searching “water conservation.”