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Submitted to: Encyclopedia of Environmental Management
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/7/2011 Publication Date: 5/1/2013 Citation: Bjorneberg, D.L. 2013. Irrigation: Erosion. Encyclopedia of Environmental Management. DOI:10.1081/E-EEM. Interpretive Summary: Irrigation is vital to food production in the world. The most cited statistics indicate that irrigated cropland produces about one-third of the world’s crop production on only 16% of the cropland that is irrigated. However, irrigation-induced soil erosion reduces productivity of irrigated land and can cause off-site water quality problems. The factors affecting soil erosion from irrigation are the same as rainfall—water detaches and transports sediment. However, there are some unique differences in how the factors occur during irrigation and in our ability to manage the application of water that causes the erosion. Surface irrigation utilizes the soil to distribute water through the field. Water flowing over soil inherently detaches and transports sediment. Sprinkler and drip irrigation distribute water through fields in pipes, eliminating erosion from water distribution. Ideally sprinkler irrigation will have no runoff, but application rates on moving irrigation systems can exceed the soil infiltration rate, resulting in runoff and erosion. Using tillage practices to increase soil surface storage and selecting sprinklers with lower application rates will reduce sprinkler irrigation runoff. Irrigation can be managed to minimize erosion and maintain productivity. Technical Abstract: Irrigation is essential for global food production. However, irrigation erosion can limit the ability of irrigation systems to reliably produce food and fiber in the future. The factors affecting soil erosion from irrigation are the same as rainfall—water detaches and transports sediment. However, there are some unique differences in how the factors occur during irrigation and in our ability to manage the application of water that causes the erosion. All surface irrigation entails water flowing over soil. Soil type, field slope and flow rate all affect surface irrigation erosion, with flow rate being the main factor that can be managed. Ideally sprinkler irrigation will have no runoff, but application rates on moving irrigation systems can exceed the soil infiltration rate, resulting in runoff and erosion. Using tillage practices to increase soil surface storage and selecting sprinklers with lower application rates will reduce sprinkler irrigation runoff. Irrigation can be managed to minimize erosion and maintain productivity. |
