Irrigation is Nevada. Photo: US EPA and National Archive and Record Administration; Wikimedia Commons.
Learn how efficient irrigation technologies and practices reduce water and power costs.
Irrigation is very important to productive agriculture, accounting for 20% of all farmland and 40% of all production worldwide. This is the major use of water in the world, accounting for about 70% of all freshwater use. Efficient irrigation systems use energy-efficient equipment and designs, and also minimize the amount of unnecessary water use, adding to the energy savings. As a result, farms that irrigate efficiently will not only reduce their operating costs but will also reduce the use of water resources that are increasingly scarce. There are two main ways a farm can improve the efficiency of its irrigation efforts: 1) improving the irrigation system, and 2) enhancing the management and operations of the system.
Modifying irrigation systems can reduce energy and costs. For example, according to the Natural Resources Conservation Service (NRCS), in certain areas of the United States, switching from high- to low-pressure sprinkler systems can save as much as $55 and 770 kWh per acre annually. In areas where ground and surface water availability is diminishing, efficient irrigation tools such as drip, trickle and lower-flow sprinkler systems save energy as well as water and money.
Some common causes of wasted energy in irrigation systems are worn or improperly sized pumps, worn nozzles, and improperly sized or designed fittings. Irrigation equipment problems and maintenance problems tend to go hand in hand. Pumps, motors, and engines that are badly designed or poorly maintained reduce the irrigator’s degree of control over water applications, making it impossible to maintain correct soil moisture levels. This leads to crop stress, reduced yields, runoff, erosion, and other problems.
On the other hand, mechanical improvements alone do not necessarily bring energy savings. Better system performance typically causes higher pressure and increased volumes of applied water. These improvements should make it possible to meet crop water needs with fewer hours of irrigation. But if the irrigator continues to run the system for the same number of hours, energy consumption often stays the same or even increases.
In order to avoid both overwatering and underwatering, all irrigators need to know their system’s net water application rate, measured in inches per hour or inches per irrigation. All irrigators should know general irrigation guidelines for the crops they grow. They should also know how to check their soil moisture levels. Most irrigators should also track crop water use, or evapotranspiration, as the season goes by.
An Irrigation Checklist is available to help with the optimization of irrigation system efficiency.
Farmers should examine their irrigation equipment and practices to ensure that their irrigation systems operate efficiently. To use energy in irrigation most efficiently, irrigators should:
The following links provide a wealth of information on energy efficient irrigation equipment and practices: