COLUMBUS – Beef and milk producers want to concentrate on their cattle. Egg producers want to concentrate on their flocks.
And that can be a problem, if they give little thought to the manure generated on their farms.
“Most managers want to focus their time and effort on the commodity they’re producing, not on manure management,” said Jon Rausch, an animal manure management program specialist with Ohio State University Extension.
Hot topic. What to do with livestock manure is a hot issue in Ohio in light of an increasing number of large livestock farms around the state.
With more concentrated livestock facilities, operators often have more manure than they have land to spread it upon, Rausch said.
Concerns, complications. Concerns have been raised regarding manure storage and application, specifically about odor and fly problems, excessive nutrients applied in soil and potentially reaching water supplies, and the risks that disease-causing microorganisms could cause human health problems.
Complicating matters is that manure can be applied to land only when conditions warrant: when the land needs to be fertilized, and when heavy rains won’t wash it away, polluting neighboring surface water.
Currently, livestock operations often use storage ponds to hold liquid manure until it can be applied to nearby land as fertilizer, Rausch said.
That works for many types of operations, especially those that are able to apply the liquid as fertilizer to nearby land.
Odor patrol. One challenge with manure holding ponds is controlling odor. Odors can be reduced by creating an aerobic environment that prevents the creation of odor-causing compounds, Rausch said.
Options include running a paddle-wheel type agitator across the pond, pumping air up through the pond, or churning the pond with propellers.
Another option, especially for dairy producers, is to pump waste into the pond from the bottom and allowing a crust – a “biofilter” – to build up on top of the pond.
“That’s an excellent way to control odors,” Rausch said.
Separation systems. One alternative to liquid storage ponds is to separate liquid from solid waste and composting the manure, Rausch said.
The advantage? The process reduces odors, and it allows producers to haul the solids farther distances at less expense. It also reduces the phosphorus content of the liquid portion of the waste, allowing more of it to be applied to a smaller amount of land.
“Phosphorus is the limiting nutrient when applying manure to land,” Rausch said.
“If too much is spread on land and runs off into streams, high phosphorus content spurs algal growth in surface water. That can putrefy the water and cause a fish kill.”
Separating solids also allows a livestock facility to produce high-quality compost and possibly sell it at a profit, Rausch said. Some Ohio producers are currently doing this, but it takes a lot of management.
Manmade wetlands. Another alternative is to treat manure in constructed wetlands that border a facility, Rausch said.
Jay Martin, an ecological engineer at Ohio State, said the advantages are many.
They’re effective at reducing pathogens, nitrogen and phosphorus levels, and biological oxygen demand (BOD), which, at high levels can cause fish kills.
“They’re cheap to operate – no chemicals or mechanization is required,” Martin said. “You can rely on the renewable energies of the sun and wind to treat the waste.”
However, they do take up a lot of space, and, like other treatment and storage systems, they require an initial investment to set up.
Application options. Several options are available for manure application, too, Rausch said. Liquid manure can be applied to land by using:
* A drop-hose toolbar or center-pivot system, in which hoses hang in rows from a bar, allowing application close to the ground, reducing odor and allowing even distribution of nutrients.
* A disc incorporator. Incorporating the manure into the ground as it is applied also helps reduce odors, “but you have to watch because it’s easy to over-apply manure with direct injecting,” Rausch said.
“Applying a large volume concentrated in a small area sometimes allows the waste to find its way into tiles, through worm holes or cracks in the soil,” he added. “That takes it directly to nearby surface water.”
* Side-dressing techniques. “Instead of trying to get all the manure on land before planting, some farmers are applying waste as side-dressing on corn fields or top-dressing on wheat fields,” Rausch said.
“Each situation on each farm is different,” said Rausch. “There is no silver bullet. There are only individual solutions to individual circumstances.”
* * *
Manure management workshop
* Best Management Practices for Manure Application workshop
June 18
Ohio State University’s Lima campus
* Determining Calibration and Application Rates
Presenters Ohio State manure specialist Jon Rausch and Mike Monnin, USDA/NRCS
* Whose Manure Is It Anyway?
Presenters Kevin Elder, Ohio Department of Agriculture; Martin Joyce, Ohio Department of Natural Resources; and Rick Wilson, Ohio Environmental Protection Agency
* Frozen and Snow Covered Land
Presenter Rick Wilson, Ohio Environmental Protection Agency
Registration: $20 before June 11; $30 after June 11, includes lunch.
Checks should be made payable to Ohio State University/FABE and sent to the attention of Jon Rausch, 590 Woody Hayes Drive, Columbus, OH 43210.
For more information, contact Rausch at 614-292-4504 or rausch.7@osu.edu.
* * *
Ohio’s CAFOs
* Currently 147 Ohio livestock operations fall under the Livestock Environmental Permitting Program rules, with at least 1,000 head of beef cattle; 700 dairy cattle; 2,500 swine; 100,000 laying hens or broilers; or 55,000 turkeys.
* At least 300 more farms are just under that threshold, and about 3,000 farms are classified as “medium” sized – at least 200 dairy cows, 700 swine or 300 beef cattle, for example.
Source: Ohio Department of Agriculture
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