Modern agriculture can create a lot of waste, but that doesn't mean it needs to go to waste. At Crave Brothers Farmstead in Waterloo, Wisconsin, they're turning that waste into profit by reusing the manure made by their cows. Liquids, solids, and even gas created by manure are repurposed around the farm in the form of fertilizer, bedding, and methane that's used to create electricity that powers the farm, cheese factory and homes in the community.
It's all made possible with the Anaerobic Methane Digester, a device that separates the different parts of the manure.
Mark Crave, one of the brothers and the general manager of the farmstead, says they've tried to create a continuous cycle on the farm that limits the need for outside resources. The liquids from manure are turned into fertilizer that the farm uses on their crops, which are then harvested and fed to the cows.
"Our number one crop is corn and corn for silage, and what that means is instead of harvesting the grain you harvest the entire plant and chop it up. Cows are ruminants, they need a lot of fiber and they can digest fiber that you and I can't. And so they do a great job of taking materials that would otherwise go to waste," says Crave.
As a result of their high-fiber diets, cow manure contains fibrous solids that are also separated by the digester and turned into bedding for cow stalls. The other main product of the manure is methane gas, a greenhouse gas that would otherwise go into the atmosphere and affect the climate.
"We collect the cow's manure... we pump it into these tanks and in there it ferments. It's about 100 degrees, we add heat to it to where it ferments at that heat and it generates methane," Crave explains.
The digester siphons off this gas and redirects it to the electrical grid. According to Crave, the electricity created by the digester is enough to power the farm, the cheese factory, and about 300 homes in the community. None of it would be possible without the digester and Crave says their ability to own and operate the digester is due to the size of the farmstead.
"We have 11 family members and 80 full-time non family staff. Everything from people that feed calves, milk cows, feed the cows, run the digester. Across the road we have lab personnel, we have several cheese makers. My brother and my nephew are cheese makers. Also, shipping receiving — the whole thing," says Crave.
It's considered a concentrated animal feeding operation, more commonly known as a CAFO. For some, the term CAFO has become synonymous with the destruction of "family farms," small-scale farms that have been pushed out of the industry in recent years. But Crave says their status as a CAFO is a sign of their strength as a family-owned farm and it forces them to operate at a higher level of environmental stewardship and sustainability than other, smaller farms.
Crave says, "We're already doing a lot of things that people want us to do. We just have to one: explain what we're doing. And two: use the science and the information; use the numbers behind it."
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