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Bob Wackernagel (right)
turned dairy waste into a lucrative resource by selling composted
manure to nurseries and tree farms.
Photo by Ken Schneider. |
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Bob
Wackernagel
Montague, Michigan
Summary of Operation
100-cow
dairy free-stall operation, with an additional 100 heifers and dry cows
Alfalfa,
corn, oats and wheat on 725 of 800 acres
Dairy
manure compost sold to area nurseries
Problem Addressed
Manure management. Bob Wackernagel
confronted a manure storage problem at his 725-acre dairy farm near
Montague, Mich. His property sits on a high water table, making
it difficult to store manure in a traditional lagoon. Once he figured
that out, he decided to scrap a lagoon manure storage system that
had been in the planning stages for several years. “In years when
it is very wet, a lined lagoon would have been partially below the
water table,” says Wackernagel.
Background
Wackernagel and his wife,
Kim, took over the fourth-generation family farm in 1992 from his father,
Robert. They have three children who help on the farm.
Greg Mund, resource conservationist for USDA’s Natural Resources Conservation
Service in Muskegon County, offered Wackernagel the option to join a
composting program through the Muskegon Conservation District in 1995.
The program, which offers grants to farmers who want to try composting
systems, was funded through the Michigan Integrated Food and Farming
System project, a W. K. Kellogg Foundation initiative. Mund helped Wackernagel
obtain more funding from SARE’s farmer grant program in the North Central
Region.
It was one of the first operations in Michigan to receive Environmental
Quality Incentives Program (EQIP) cost-share funds for a compost manure
management system.
Focal Point of Operation
— Composting
Wackernagel began composting
dairy manure, using a 60-by-120 foot concrete holding pad and a one-half
acre composting site. Wackernagel handles the manure with a compost
turner he shares with four neighboring farmers. By turning his manure
into compost, Wackernagel produces a highly marketable product that
was previously a manure management problem. Every spring, he sells this
“natural fertilizer” to area nurseries.
Producing good quality compost from manure involves several steps and
close management. The process begins in Wackernagel’s free-stall dairy
barn and heifer barn, where he adds bedding material to put carbon in
the manure.
“You just can’t take manure and start running a turner through it and
make compost,” Wackernagel says. “You have to add some carbon first.”
In the free-stall barn, he overfills the stalls with sawdust. When the
cows back out of the stalls, they rake some of the sawdust into the
alleyway, which in turn mixes with the manure. The cows help make a
material that can be stored and won’t run off like liquid manure. He
uses about 40 yards of sawdust per week in the free-stall barn. He adds
oat straw to beds in the heifer barn. Composting manure and straw separately
from the sawdust mixture allows Wackernagel to spread a straw-based
mix as a foundation for his compost windrows.
Wackernagel sometimes adds extra sawdust to the manure if it has more
moisture. He also is able to dispose of spoiled or moldy feed or bad
haylage, from bunker silos, which are high in carbon, by adding them
to the manure mixture.
Wackernagel hauls manure and bedding to one of three places. About 30
percent is directly spread on the fields. The rest is either taken to
his concrete holding area or immediately made into windrows on a specially
designed composting site. The system gives Wackernagel the flexibility
to spread manure on the fields on days when he doesn’t have more pressing
activities such as making silage and baling hay. He uses the concrete
holding area mostly in the winter, when the snow is too deep to make
windrows or spread.
Wackernagel builds most of the windrows in the winter, weather permitting,
and in early spring. The windrows are built on a composting site that
sits on eight inches of crushed and compacted limestone and has runoff
ditches on either side to drain off rainwater into a vegetative filter
strip system. The windrows start out at 10 feet wide by 4 feet high
by 160 feet long. The site will hold eight windrows with room to operate
the manure turner.
Wackernagel keeps the windrows covered with large fleece blankets. The
breathable fabric sheds water and keeps the compost dry until it is
time to begin turning.
Wackernagel begins turning the manure in March to have compost ready
to sell to nurseries and tree farms by May. The peak marketing time
for his compost is from April to the first week in June.
Wackernagel works the pile when the temperature dictates, about every
seven days. When the internal temperature, checked with a probe, reaches
140 to 145 degrees, the manure is ready to be turned. The carbon/nitrogen
(C:N ratio) content must be at least 30 to 1 for the mixture to heat
up to the desired temperature. Usually a 1 to 1 carbon (sawdust, straw,
etc.) to manure volume is a good starting recipe.
“When you turn it, you are exhausting the carbon dioxide and water,
and replenishing the oxygen,” says Wackernagel. “The bacteria in the
compost can breathe again and continues to break down the carbon.”
Besides breaking down the manure and carbon into compost, the process
reduces the water in the manure, which cuts the volume to be hauled
by 50 to 60 percent. The high temperature also kills many weed seeds;
Wackernagel has seen his compost kill velvet leaf and ragweed seed.
The farmers sharing the compost turner, provided as part of the conservation
district grant, worked out an informal schedule to transport the turner
from farm to farm when needed. The turner requires at least an 80 horsepower
tractor to operate effectively. The tractor’s power takeoff runs the
turning rotor, and the hydraulic system runs a rear axle that creeps
the compost turner forward while the tractor is in neutral.
The initial turning of a new compost windrow is done at a rate of less
than 0.2 miles per hour, says Wackernagel. As the compost breaks down,
it becomes easier to turn and the speed can be increased slightly. On
average, it takes Wackernagel about half an hour to do four windrows.
The carbon content
in the manure will determine the length of time to produce finished
compost. Compost made with sawdust will take from 55 to 60 days to finish
and compost made with straw, which has a lower carbon content, will
take about 70 days to finish. The sawdust compost also has a more even
particle size and consistency than the straw compost. The windrow is
done when compost temperatures reach ambient temperature, with an additional
20- to 23-day curing period for off-farm uses.
Marketing the compost has never been a problem. Wackernagel put an ad
in the local newspaper the first year and has not advertised since.
Sometimes, he runs out of compost and has to refer his customers elsewhere.
“I sell so much compost I hardly have a chance to use it on our farm,”
he says. “I use some on the fields before I plant soybeans and oats
and use a little to topdress alfalfa.”
Economics and Profitability
Wackernagel sells compost
in bulk for $15 per cubic yard. The compost can vary in moisture from
nearly powdery dry to 25 to 35 percent moisture, with a cubic yard averaging
from 1,200 to 1,500 pounds. He sells anywhere from 300 to 500 tons each
year.
The compost sales provide a supplement in the spring that covers parts
for machinery, oil and other supplies. The compost Wackernagel uses
on his own fields also has reduced his fertilizer costs.
He ran a test on a 40-acre field of soybeans, comparing compost to synthetic
fertilizers. On 20 acres, he used only compost and a small amount of
potash; on the other half, he added 150 pounds of potash and about 20
pounds of nitrogen per acre. When the results were in, Wackernagel found
that the composted field out-yielded the “traditional fertilizer” field
by about 15 bushels to the acre. Wackernagel notes that oats also respond
well to compost, yielding about 100 bushels per acre of high test weight
oats.
Wackernagel also saved money by not building a more costly lagoon manure
storage system, even considering a government cost-share program that
would have helped pay for pumps and liners. The composting management
system cost about $23,000, of which Wackernagel paid about $7,500 to
match the government cost-share.
Compost turners cost between $18,500 and $26,000. “It wouldn’t be cost
effective for someone with a 30- to 50-cow farm,” Wackernagel says.
“But it could work for someone with a large operation. It just depends
on how serious you are about composting, or if a few farms can share
a turner.”
Environmental Benefits
Wackernagel became involved
in composting manure more for the economic boost than to lessen the
dairy’s impact on the environment. Nevertheless, he says that manure
disposal needs to be handled carefully through such environmentally
friendly systems as composting. He is pleased to eliminate odors and
water and provide greater opportunities for spreading. It also adds
the benefit of producing an organic fertilizer.
Community and Quality of Life Benefits
Wackernagel says his area, like much of the country, is being developed
for housing. “These people want to live in the country,” he says. “But
they don’t want it to smell like the country. And the compost doesn’t
have the odor that raw manure does.”
What smells in manure is the urine — which is basically nitrogen, says
Wackernagel. During the composting process, the carbon absorbs the urine,
which microbes break down into humus, with some methane gas lost into
the air.
“So you can spread right along side a neighbor’s house and it looks
like you are spreading black dirt and there’s no odor,” he says. “There
are also hardly any flies, either when spreading or when making the
compost.”
Transition Advice
Wackernagel recommends composting as a positive way to deal with manure
disposal. He says anyone interested in setting up a system should call
their Natural Resources Conservation Service or Conservation District
office.
He has learned one valuable lesson that would cause him to do things
differently from the start. “I wouldn’t recommend a limestone base for
the composting site,” he says. “We found out that when you start turning
the compost, some of the limestone peels up and gets mixed in.” He recommends
either black top or concrete.
The Future
Wackernagel plans to pave over the limestone composting site with concrete.
Wackernagel and his neighbors may eventually jointly buy the compost
turner, which they currently lease. And finally, when Wackernagel decides
to expand his dairy operation, the composting system will be flexible
enough to accommodate the additional manure, unlike a lagoon system.
 Profile written by Mary Friesen
For more information:
Bob Wackernagel
6673 Fruitvale Road
Montague, MI 49437
Greg Mund, technical adviser
(231) 773-0008
greg.mund@mi.usda.gov
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