As state agriculture officials scramble to pin down the source of a mysterious crop die-off that has cost farmers in Whatcom County hundreds of thousands of dollars so far this year, a Washington State University researcher who traced a similar crop kill a decade ago said he had worried that the problem would re-emerge.
The researcher found the earlier problem stemmed from a powerful and long-lasting herbicide that made its way into compost, and he said he had feared the state's failure to ban spraying the herbicide on hay and wheat might lead to a new round of trouble.
The herbicide, Clopyralid, and its newer and more powerful chemical cousin, Aminopyralid, are used by hay and grain farmers, primarily on the eastern side of Washington, to keep down thistles and other broadleaf weeds. Washington State Agriculture Department (WSDA) investigators recently found both herbicides in compost on several Whatcom County farms where the latest crop kills have occurred.
Garry Hamlin, a spokesman for Dow Agrosciences, the Dow Chemical Co. subsidiary that makes Clopyralid and Aminopyralid, told Crosscut the company is aware of its herbicides are showing up in Whatcom County.
"We've been working with local regulators to get to the bottom of this," Hamlin said. "There's been a breakdown in the stewardship of our products and we need to find out how that happened and shut it down."
While the latest Whatcom County problem has mainly been confined to organic farms, compost made from animal manure is widely used on organic and non-organic farms and gardens all over. Tracking a long-lasting herbicide through a chain of hands — from hay farmers, to truckers, dairies, and horse farms — before it finally ends up as compost on a vegetable or fruit farm could pose a daunting problem for regulatory officials.
Both Clopyralid and Aminopyralid are classified as safe for human exposure by the U.S. Environmental Protection Agency. WSDA allows the herbicides to be sprayed on wheat and other grains.
"In the testing (of Clopyralid and Aminopyralid) WSDA has conducted to date in this investigation, residue levels we are finding are far below what is allowed to come into the marketplace," WSDA spokesman Jason Kelly said in a statement to Crosscut. "The issue here is inadvertent damage to plants, not impact on human health."
Clayton Burrows, a Whatcom farmer who operates Alm Hill Gardens, a 70-acre organic farm in Everson, Washington, said he asked WSDA for help in June after the farm lost $250,000 in produce this spring. Alm Hill usually harvests some 3,000 pounds of tomatoes each year from each of its several greenhouses, Burrows told Crosscut. This year, the farm's July tomato crop, he said, was just 20 pounds, although the season has just started and there will certainly be much more to pick, with some areas of the farm unaffected by the problem.
Burrows said he was surprised when WSDA investigators found Clopyralid and Aminopyralid in compost the farm was spreading on its beans, tomatoes, peas, raspberries and other crops. "We're an organic farm and we don't use herbicides," he said.
Since then, Burrows said, he has heard from a half-dozen other farms and a number of home gardeners in Whatcom County who are having similar problems. Whatcom grower Kirk Hayes told the Bellingham Herald last week that he lost $40,000 in organic potatoes and salad crops in two months after he spread tainted compost on seven-and-a-half acres of his farm.
Dow voluntarily pulled Aminopyralid off the market in Britain in 2008 after farmers there reported the failures of crops exposed to compost that had been made from silage sprayed with liquid manure that contained the herbicide. Dow reintroduced Aminopyralid in the UK this year, Hamlin said.
Clopyralid has also shown up in manure in California. Kjell Kallman, general manager of Grab & Grow, a Santa Rosa, Calif., commercial composter, said his company now tests every load of manure if receives from local ranchers because of herbicide concerns. "Occasionally, we find traces of Clopyralid," Kallman said. The company rejects any manure containing the herbicide, he said.
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