People need food. Desert soils are generally very fertile, as there is very little water to wash out the nutrients. In order for most food crops to grow (wheat, corn, barley, etc.), irrigation is needed. Irrigation has the capacity to increase crop yields over 10 times compared to fields without irrigation. Without proper management, the soils can become a salty mess, incapable of crop production.
Poor soil that is damaged by accumulated salt content from poor quality irrigation water near Mexicali, Mexico. May 1972. Credit: Charles O'Rear. US Archives 412-DA-6597
Where does the salt come from?
Basin flood irrigation on wheat. Yuma, Az. Credit: Jeff Vanuga, USDA-NRCS
Why is salt a problem?
Changing Groundwater Tables
Different Types of Salinity
Salt-affected soils are visible on rangeland in Colorado. Salts dissolved from the soil accumulate at the soil surface and are deposited on the ground and at the base of the fence post. Credit: USDA NRCS
Drip irrigation can reduce evaporation.
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