FIVE POINTS, Calif. (AP) -- A hardy but pedestrian plant is doing triple duty in California's agricultural heartland.
Farmers, water managers and agriculture researchers are closely watching an experiment using canola plants to absorb the salt from soil and water. The seeds are then crushed to extract oil for blending into environmentally friendly biodiesel.
If that were the end of the story, it would be just another case of farmers turning food into fuel. Yet at John Diener's Red Rock Ranch in this town 60 miles southwest of Fresno, the selenium-rich canola byproduct has an even higher calling: cattle feed naturally infused with an essential micro-nutrient.
"It's all part of what we have to try to do here to turn a profit," said Diener, who also grows almonds, tomatoes, grapes and corn on 5,000 acres.
In a trial, Diener's canola meal - grown on once-fallow land - was fed to dairy cows on the east side of the San Joaquin Valley, where selenium does not occur naturally and has to be added to food rations.
If the USDA's experiment is successful, officials say they will try to persuade other farmers in the region to start planting canola and other selenium-tolerant plants.
"These challenges force farmers to become smarter, and that's where science comes in," said Gary Banuelos of the U.S. Department of Agriculture's research station in Parlier, who manages test plots at Diener's ranch.
There is urgency to the effort because the ongoing drought and court-ordered water rationing to protect threatened fish species means farmers who have relied for decades on state and federal water deliveries via canals are being forced to turn to groundwater pumping.
Irrigation water that passes through the soils picks up toxins as it percolates. And what to do with that drainage has vexed farmers, water managers and attorneys since the Bureau of Reclamation's drainage ponds at the Kesterson Reservoir closed in the 1980s after selenium caused often-fatal birth defects in millions of waterfowl.
Whether canola can cure the valley's groundwater and soil problems and become a viable crop is the challenge facing the U.S. Department of Agriculture.
Diener installed drainage pipes under some of his fields to funnel the percolating water to the once-fallow areas where it irrigates canola and other salt-resistant plants such as prickly pear cactus and poplar trees.
If Diener, 57, can find a crop that can grow profitably using marginal soils and groundwater, he can increase his farm's productivity, help solve the drainage issue and perhaps make farming economically attractive to his adult children. The canola crop even yielded the oil that Diener blended with regular diesel to power his tractors.
For eight weeks this summer, Banuelos fed six pounds of the leftover canola meal each day to 36 Jersey and Holstein dairy cows at California State University at Fresno as part of their 100-pound rations, eliminating the need for adding the critical dietary salt.
The cows did well, Banuelos said, and produced a milk with trace amounts of selenium, a potential cancer-fighter that humans need in small amounts for good health.
Diener is readying his fields for his second crop of canola, with yields of $300 an acre that pale next to the $6,000 an acre he can earn growing almonds on his prime land. But the potential to sell it as a dietary supplement for some of the San Joaquin Valley's 2.5 million dairy cows holds promise.
"It's potentially the most valuable part of the process," Diener said. "In the end, we're capitalists."