Billowing cylinders of smoke stacked precariously into the summer sky. As more acres of straw burned, the air seemed to reflect the blackened earth and took on its own oppressive murkiness. Spiraling streams of smoke added to the darkening day.
On “Black Tuesday,” August 9, 1969, the wind churned gigantic clouds of smoke from thousands of acres of grass-seed fields across the Willamette Valley, downwind and southward. Oregon Governor Tom McCall, who was in Eugene that day, witnessed the blackened skies. On his return to Salem, he declared a 10-day emergency ban on field burning.
Since the 1940s, grass-seed fields in the Willamette Valley had been routinely burned after seed harvest as an efficient means to clean the fields of disease and to reduce straw. The practice began when an accidental burn eliminated “blind-seed” disease, a troublesome fungus that keeps the seed from germinating.
“Field burning was cheap and accomplished so much efficiently,” said Mark Mellbye, an Extension agronomist with Oregon State University who has spent much of his career working with grass-seed growers in Linn County.
The number of acres burned each year peaked at 315,000 in 1969, the year of Black Tuesday and the year that more than 5,000 complaints were made to the State Board of Health. The Oregon legislature soon mandated that field burning be phased out over a series of years.
A major turning point for the Oregon grass seed industry had arrived. Dave Nelson of the Oregon Seed Council called it “one of the greatest political redirections of agriculture in the U.S.” Many grass-seed growers called it a disaster and thought the grass-seed industry would collapse.
The industry didn’t collapse. But more than a change in management practices emerged from the teamwork of farmers and researchers from OSU and the U.S. Department of Agriculture. “It’s been a whole mind shift,” said Mellbye, who worked for more than 20 years to help growers find alternatives to field burning. “And it’s been one of the success stories of the grass-seed industry.”
Together growers and researchers experimented with ways to mimic the results of field burning. They set up trial sites on farmers’ lands to test various ways to deal with the leftover straw, weeds, and disease, according to Bill Young, an OSU Extension seed-production specialist, who helped with the research. “The sites were close to home for the farmers and showed them what could be done. It made adoption of new techniques more rapid,” he said.
Researchers found that baling straw after seed harvest and removing it from the field was a viable alternative to field burning. Today, that is how most non-burned acres are managed, and the practice has created a new export industry, sending more than 600,000 tons of baled straw from Oregon to Japan, South Korea, and Taiwan each year.
Perhaps the most surprising discovery was that straw left after harvest does not have to be removed from the field at all. “It sounds simple,” Mellbye said, “but we realized we didn’t have to get the straw off the field, just off the crown of the plant.” He found that for many varieties of grass seed grown in the Willamette Valley, the straw can be spread out, chopped, and left to compost on the field, improving soil quality as it decomposes.
Even the dreaded blind-seed epidemic did not return. Researchers found that by planting varieties of grass seed that mature later in the spring, farmers could avoid much of the wet weather that allows blind-seed disease to flourish.
With each discovery, the mindset of growers changed from panic to optimism. With effective residue management becoming the accepted practice by the 1990s, grass seed fields in Oregon grew by 150,000 acres. The price of grass seed rose with increased demand for lawns around homes and parks, specialty turf for golf courses, and grasses for animal forage. Growers were able to invest in equipment to improve tillage and straw management, according to Mellbye. They discovered they could save $40 to $60 an acre in fertilizer by chopping the full straw load. As growers recognized the benefits of composting straw rather than removing it in bales, there has been a drop in exported straw, Young said.
Don Wirth, a long-time grass-seed grower from the Tangent area, sees improved soil structure when he takes soil samples from his fields. “Our soils are changing,” he said. “You can see improved organic matter, with microbes and earthworms; much more than some of us thought there would be.”
Field burning has not completely disappeared; 33,110 acres were burned last year in western Oregon, about one-tenth the acreage that was burned in the year of Black Tuesday. But east of the Cascade Mountains, field burning has been the only option for grass-seed growers. That’s where the best seed grows for Kentucky bluegrass and rough bluegrass, varieties well suited to central Oregon’s dry, high-desert climate.
Bluegrasses need sunlight down into the plant to produce the next year’s crop, according to Marvin Butler, superintendent of OSU’s Central Oregon Agricultural Research Center in Madras. Field residue has to be eliminated, and the best way to manage straw and disease after harvest has been to burn the fields.
In the last several years, central Oregon farmers have shouldered responsibility for smoke management and safety, according to Butler. Growers began working with Butler and other scientists at the research station to find ways to better mange smoke while they sought alternatives to burning bluegrass fields. Together they developed the use of pilot balloons released before burning to indicate wind speed and direction. Growers voluntarily imposed a “no-burn” zone next to highways and hired flaggers to work with local law enforcement staff to stop traffic when smoke becomes severe. Currently, Butler and other OSU researchers are testing 15 varieties of Kentucky bluegrass to determine if any can be grown profitably for seed without burning the fields.
Back in the Willamette Valley, Dave Nelson, executive secretary of the Oregon Seed Council, credits OSU scientists for helping farmers make an important change in how problems are solved in the Oregon grass-seed industry. “OSU researchers changed their role from telling farmers how to do things to tracking what everyone was madly trying to do to save their farms and stay economically viable,” Nelson said. “Farmers were testing everything in the world, and OSU researchers were evaluating the effectiveness of all these different practices. It was a great service to the industry, and it made conversion possible within six or seven years.”