Spreading thin

SALEM, Ohio – Steve Miller cut his fertilizer use in half in the last three years and still wound up with the best soybean yield of his life last fall.
How’d he do this? This central Ohio farmer can’t say for sure but he’s pretty certain his use of sludge helped.
Sludge, also called the more public-friendly “biosolids,” has been spread across fields for years. But with today’s increasing fertilizer costs, some farmers are taking a closer look.
Somewhere to go
Think of all the waste generated every time you dump leftovers into your garbage disposal, every time the bath water swirls down the drain, every time the washing machine empties the sudsy detergent, every time you flush the toilet.
All this waste has to go somewhere after it hits the local wastewater plant. But where? There’s only so much landfill space and dumping it into the ocean was outlawed years ago.
Imagine it being recycled into a product that can be spread on your fields for free. A recycled product that may add nitrogen and cut your fertilizer bill. A recycled product that could improve soil quality.
Of course, something so closely associated with feces and decaying food and dirty laundry isn’t embraced by everyone.
Supporters and opponents have wrangled for years, reaching a boiling point in the early ’90s, first when a Washington dairy farm launched a very public lawsuit alleging sludge made the owners sick and killed their cattle, and then in 1993 when the EPA issued new rules for biosolids’ use.
Now, more than a decade later, many experts think biosolids have come a long way and, if handled correctly, may be an answer to farmers’ financial woes.
It’s used out there
Sludge is applied across 30,000 acres of Ohio farmland each year, according to Ohio EPA’s Suzanne Matz, field coordinator for the Division of Surface Water.
Another 270,000 acres are also OK’d by the EPA but currently aren’t in use, Matz said. And it’s likely that many more acres could also be approved.
Technician Brian Alger is working through a company called Synagro to let farmers know their ground could be next.
Heavy tillage depletes a soil’s organic matter but biosolids will restore it, Alger said. The organic nitrogen in biosolids releases slowly, unlike commercial fertilizers, meaning it’s more available to the plant during the growing season, he said.
For no-till fields, Alger said biosolids increase the soil’s moisture-holding capacity.
Free fertilizer?
Biosolids are high in nitrogen and phosphorous, Alger said, but they don’t provide all nutrient needs. Think of them as a soil amendment, he said, not a fertilizer replacement.
But because biosolids are free to farmers, they will definitely cut fertilizer costs, Alger said.
And farmers aren’t stuck with extra labor.
Companies like Synagro handle the contracts with local wastewater plants, then recycle and land apply the biosolids on the fields, all under EPA oversight. Wastewater plants can’t wait to get rid of the material, and many farmers like the idea of a free fertilizer supplement.
But one thing often stands in the way. Public perception.
There’s a lot of misunderstanding about biosolids, Alger said.
People think of biosolids, or sludge, and imagine feces floating in a field, and that’s not true, he said.
Urine, blood, metals?
But if farmers saw what Tom Marshall sees in his position as public utilities director in Delaware, Ohio, they wouldn’t even consider spreading sludge on their fields, he said.
Urine, blood, bodily fluids, household chemicals, industrial and manufacturing waste, heavy metals, hospital waste, radioactive material, tampons, needles, gum, cigarette butts. Anything that fits down a drain can end up at the plant, said Marshall, who is also a food, ag and biological engineer with Ohio State.
“Many times I’ve had to go out to farmers’ fields after it rains and pick up condoms,” he said. “I’ve had to do this more times than I can count.”
Although the industry has tried to screen or grind this trash, “significant amounts” still end up in fields, he said.
For these reasons, the city of Delaware no longer allows its sludge to be used agriculturally, Marshall said.
‘The boron field’
One of the last straws, Marshall said, was about 20 years ago when one field died after a sludge application. Soil tests showed the ground was overloaded with boron and even after the top 6 inches of soil was scraped, no crops would grow, he said.
Further investigation showed an industry in town used boron and a few times a year it would rinse its tanks, flushing remnant boron down the drain. Apparently the farmer happened to get a load of sludge right after the company rinsed its tanks, he said.
“We spend a lot of time and energy treating sludge to make it innocuous,” he said. “The harm can be reduced but not removed.”
That’s because wastewater plants can’t test for everything that could possibly come down the drain, Marshall said.
Although the plants are tested twice a year for priority pollutants, that doesn’t show what’s being flushed into the plant daily, he said. Dangerous materials, such as in the boron case, usually aren’t continuously coming through the plant, he said; it’s only when industries are rinsing their equipment or there’s an accident.
Marshall acknowledges using sludge isn’t all bad.
For example, he said, land application on a stripped mine land would be good for the soil.
“But take a nice, pristine farm field and it will go downhill.”
Stick with it
After three years of using biosolids, farmer Steve Miller said he’s never picked up, or even seen, trash in his fields after a sludge application.
And since his crops are growing better than ever and his fertilizer costs are down by half, he plans to stick with it.
Yes, there are concerns and cautions … just like with fertilizers, he said. That’s why Miller did his research before signing an agreement and continues to do soil tests and monitor his yields.
Miller has a 450-acre bean-wheat-corn rotation in Fairfield County, Ohio. Each spring, sludge is applied to one-third of his fields prior to soybean planting. Afterward, his no-till planter helps incorporates the sludge into the ground.
From the start, Alger and Miller worked together, putting in writing how Synagro would be responsible for applying the biosolids, listing fields that could be used, and marking buffers around waterways. They tested the soil to be sure the phosphorous was below 150 parts per million and the pH was above 5.5.
At the end, Ohio EPA reviewed the paperwork, visited the fields and gave its OK.
The big question
One of Miller’s major concerns, and the one Alger gets asked about most often, is the smell.
Alger says it’s a musty scent, but not like manure’s sulfur odor, and Miller says it usually lasts about two or three days.
Each Christmas, Miller visits his neighbors with homemade fruitcake and scented candles and explains what biosolids are and tells them they may smell it for a couple days in the spring.
So far, he hasn’t had any complaints.
Because of odor concerns, biosolids are usually applied in fields sitting off the road and not near many houses, Alger said. EPA requirements say sludge can’t be spread within 300 feet of wells or 33 feet of waterways. Plans near housing developments typically aren’t approved, he said.
Many local wastewater plants address public concerns with their own sets of regulations, Alger said.
For example, a local management plan may specify biosolids can’t be applied after 5 p.m.
Everything about biosolids is regulated from the federal level down to the local level, Alger said.
It’s safe, it reduces reliance on landfills, it helps farmers cut down on input costs, he said.
“Now,” he said, “we just have to make it politically correct.”
(Reporter Kristy Hebert welcomes feedback by phone at 800-837-3419, ext. 23 or by e-mail at khebert@farmanddairy.com.)
* * *
Biosolids basics


Up-to-date agriculture news in your inbox!