Keyvan Malek

Under what climatic conditions will it make economic sense to switch to a new irrigation system?

Posted by Keyvan Malek | March 2, 2017

High-efficiency drip irrigation system in wine grapes, a perennial, high-value crop in the region. Photo by Flickr user davitydave under CC BY-NC-SA 2.0.

Investing in efficient irrigation systems usually requires significant capital. As with other capital-intensive investments, doing it would only make economic sense if the benefits exceed the costs. Each farmer can estimate the cost of switching their system to a high-efficiency system. But what about the benefits? What do they depend on? And will those factors they depend on change in the future? We used a model to play out some “what if” scenarios to address these questions in Washington’s Yakima Basin (see this article on using models in this way).

Efficient irrigation systems can improve yields through a more efficient delivery of water to the root zone, where crops can access it. Say you have 2 acre-feet of irrigation water available. With a traditional system you might lose 40% of that water through evaporation, drift, or percolation beyond the rooting depth, so your crop will only have 1.2 ac-ft to use. With a high-efficiency system, that availability might go up to 1.9 ac-ft or more, which allows the crop to produce higher yields. Read more »

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Email: keyvan.malek@wsu.edu