Here’s an interesting fact for your next Zoom call “ice breaker,” an 800-pound cow will produce about 100 pounds of poop a day.
There are about 9 million dairy cows in the United States at any given time, producing about 900 million pounds of poop a day. Second in volume only to the House and Senate.
It’s a lot of poop, and of course one of the results of their waste is methane.
Before we all get on our Impossible Burger soapboxes, there are technologies available today that are harvesting the power of cow poop to help capture methane gasses, recycle water for farms, and even create fertilizer that is cleaner and more abundant than peat moss and other fertilizer components.
Yes, there is a peat moss shortage.
Peat moss grows naturally in bogs and takes hundreds of years of erosion and decomposition to create.
When it comes to growing cannabis, peat moss is an excellent soil component.
Using peat moss to grow things isn’t news, even that very “green” Impossible Burger is “plant based.”
The root word “plant” meaning it also comes from the ground and needs, you guessed it… fertilizer.
The availability of high-quality fertilizer like peat moss is on the decline.
As farmers look for fertilizer that can help grow quality crops, cow poop could provide the solution by the way of a 200-year-old technology called the anaerobic digester.
In 1808, Sir Humphrey Davy discovered that the methane in cow manure could be used to create renewable energy.
200 years later farmers around the country have installed “digesters” on their land to help subsidize declining profits as well as reduce their farm’s ecological footprint.
Anaerobic digesters can help curtail methane release by burning the gas and converting it to carbon dioxide.
A digester captures the methane before it has a chance to escape into the atmosphere in its pure form.
Digesters do more than generate a sustainable source of electricity, they also reduce greenhouse gas emissions.
Landon Van Dyk from Van Dky-S Holsteins Dairy Farm walks us through the science of poop power.
“If we can capture the methane rather than just allowing it to vent to the atmosphere, we can utilize it for beneficial purposes.”
The Vander Haak Dairy Farm in Lynden, Washington was the first in the state to install an anaerobic digester.
Owner Steve Vander Haak noted, “We’re producing clean renewable energy. We look at the digester as an opportunity to diversify our farm, do good things for the environment, and be able to keep farming.”
Filling the Tank
If you go back to the math portion of this article, the Vander Haaks’ 500 cows produce a lot of poop, the digester converts their manure, plus food waste from nearby food processors, into energy and other saleable products.
Restaurants and stores all are able to dump their outdated and spoiled food into the digester instead of a landfill.
Think of the digester as an extension of the cow stomach, it’s a big concrete tank 16 feet in the ground where farmers put manure and food waste, then heat it up to 100 degrees.
It starts with the cows that produced the manure, farmers gather that up and bring it to the digester, where methane gas is produced and a generator turns it into electricity, returning it back to the grid.
Van Dyk explains an incredibly complex process in as simple terms as possible.
“We collect the manure and add it to our digester. At that point, the bugs that were working in the gut of the cow to break down the complex organic bonds continue to act the same way in the digester. They’re breaking down that energy, creating methane, and they also reduce that fertilizer value from a complex, somewhat unavailable organic material to an inorganic material that’s readily available to plants.
A Versatile Byproduct
Cliff and Andrea Sensenig have a much smaller dairy farm of about 100 cows in Pennsylvania, which isn’t enough to make a digester profitable, as Andrea Sensenig explains.
Instead of abandoning their idea, they reached out to other farmers in the community.
“We were able to add pigs and chickens. Where you see poop, we see a recycling opportunity. We also add some food waste into the mix to create methane gas and then capture that gas, pipe it into an engine, and it creates electricity. We’re producing enough electricity to power this farm and 140 additional homes.”
More than methane, it’s an abundance of clean, very rich fertilizer that when mixed with soil can provide farmers and cannabis cultivators the materials they need to grow, while at the same time helping the environment by recycling… poop.
“Through the process… we would separate the liquid from the solids and use the liquid as a fertilizer. It is actually a good fertilizer because it’s more readily available than straight cow manure, so when you apply it you get a faster reaction than you would putting on manure,” says Van Dyk.
Andrea Sensenig adds “The food waste we’re getting right now is coming from large chain grocery stores. If we weren’t adding the food waste to our digester along with the manure, all this food waste would just be added to landfills. What we’re doing is landfill diversion.”
Cows for Cannabis
Van Dyk farms potatoes but explains how using soil from a digester could work for the cannabis industry.
“The pathogens that are in the [digester] manure are essentially very low, they are significantly reduced from regular cow manure.”
While anaerobic digesters are still few and far between, they are providing a solution that helps prevent more methane from being released into the atmosphere, as well as creating a sustainable form of fertilizer the cannabis industry can turn to as a resource for fertilizer.
To Vander Haak it goes much deeper than that.
“If farmers weren’t concerned about sustainability and conservation, there would not be the safe food supply we have today. I want my kids to have the opportunity to follow in my footsteps, in my dad and grandpa and great grandpa’s footsteps. The land is one of our resources and we need to be able to use that land both now and in the future.” ϖ