The four-year drought in California has heightened attention to a long-running problem for irrigated agriculture in the Central Valley: the salt that accumulates in the soil over the years from the crop-sustaining water, says Environmental Health News. Options range from draining away briny subsoil water to retiring land altogether because crops can no longer grow on it.
The Regional Water Quality Control Board in the Central Valley accepted a plan this month that calls for moving salt-laden water along a “brine line” to the San Francisco Bay for discharge into the ocean after it has been cleaned of contaminants and farm runoff. The project, 10 years in development, “would require funds from local, state and federal sources,” says EHN.
“To some extent, growers can choose crops less sensitive to salt,” says EHN, using the example of a farmer who says pistachios are more tolerant to salt than other crops. Water pumped from wells tends to be saltier than water diverted from rivers, so growers can try to get better-quality water for irrigation. Plant breeders are working on crop varieties that are less sensitive to salt as well. “Ultimately, though, some farmland is unsalvageable,” says EHN. The Westland Water District has retired 88,000 acres because the soil is too saline. Solar panels now sit on some of the land.