The Pitchfork Pulpit: Composting Livestock Manure

If you aren’t already composting your livestock’s manure for the garden or field, you’re missing out!

Fertilizer

Poultry and pigs pull double doo-doo duty at Polyface Farms by producing their own manure and turning the dung pile!

Photo by Fotolia/Schweinepriester

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Anyone who raises livestock on a farmstead knows that much of animal husbandry revolves around properly handled manure. To be sure, manure is one of the greatest benefits of livestock, which is just as valuable as the milk, meat, or eggs that your animals produce. Unfortunately, farms rarely leverage manure assets to their full potential for fertilizer. Composting horse, cow, and chicken manure is one of the best ways to maximize the value of your livestock, and, with a little planning, the process can be an enormous benefit to your livestock and your soil health.

Growing up, my family always had a compost pile — kind of a glorified weed pile — next to the garden, but my manure management epiphany occurred as a teen. Our farm was a gullied, rock pile of poverty when my mom and dad purchased it in 1961. Thankfully, they were creative. Dad developed a portable electric fencing system and began rudimentary cattle rotation right off. He hauled in corn cobs from the local grain elevator (this was before combines) and spread them on the rocks. For winter feeding, we put up loose hay with an old-fashioned hay loader, using a grapple fork to unload it in the barn. Dad developed a V-slotted feeder gate that spanned the hay storage area so the cows could feed off the face of the hay. As they ate, we simply moved the long gate a few inches forward. This was certainly an easy way to feed hay, but it created a manure and urine buildup problem.

When the barn’s concrete floor became covered with several inches of manure, we’d pitchfork out the chaff and leavings that would collect in front of the hay gate, but that did little to absorb all the sloppy droppings. Throughout winter, we’d clean off the floor and spread the buildup on the fields with a manure spreader. To our surprise, the material that we spread in January did practically nothing to help fertility, but what we spread toward the end of the winter and in early spring — right as the grass greened up — delivered dramatic results. Same material, same field, different time.

Then, I got it: The dead-of-winter material couldn’t be metabolized by the dormant soil microorganisms, and it simply leached out or vaporized away by springtime. Capitalizing on the manure asset would require more strategic thinking about application timing, which inevitably necessitated storage.

Putting the manure outside would expose it to the same elements that robbed us of nutrients in the first place. Practically, the manure was too sloppy to compost, and besides, compost needs about 50 degrees Fahrenheit in ambient temperature to get started. The ideal solution was storing manure in place, protected from the elements, before composting. That meant we had to get more carbon into the animals’ lounge area.

Balance Nutrients and Microbes for Quality Compost

Good composting requires that we balance five things: carbon, nitrogen, moisture, air, and microbes. I’ve never had a problem getting enough microbes; if that’s an issue for you, you can always add some soil. Animal manures contain a multitude of microbes.

Fresh manure is too high in nitrogen to compost directly. Different animals generate different carbon-to-nitrogen ratios in their raw excrement. Cows produce manure with a ratio of about 18-to-1, and chickens generate a 7-to-1 ratio, which is why we refer to poultry manure as “hot.” By the same token, other carbon sources vary in ratio: Sawdust is about 500-to-1, wood chips (no leaves) are 250-to-1, deciduous leaves are 35-to-1, and straw is 100-to-1. Ideally, compost should be about 25-to-1 to 30-to-1.

On the ideal farm, the proper balance and mixing occurs by default. As much as a pasture-based farmer like me would love to see animals outside all the time, that’s neither desirable nor practical during some seasons. Chickens don’t enjoy a couple of feet of snow. Plus, in a cold snap, water lines freeze and the basic requirements of animal care become arduous.

In late winter, during thaw, a cow herd can do significant damage to the soil through pugging. Ditto for pigs. By solving our conundrum of storage in situ and restoring proper C-to-N ratios, we were led back to the ancient practice of bedding, or the static manure pack. Gene Logsdon described this as eloquently as anyone in his little book Holy Shit. Don’t let the title dissuade you; it’s a great read.

Build Bedding Packs to Compost Livestock Manure

Old-timers in our neighborhood tell me that one of the first chores for farm boys was picking up cow pies in the barnyard, putting them in a wheelbarrow, and toting them into the barn. Covered with straw and then stepped on by the animals, these fertility pies suddenly enjoyed the protection and stability afforded by being placed inside. I call my bedding pack a carbonaceous diaper. The deeper the diaper, the better it works. It’s a magnificent sponge that performs many functions.

First, it absorbs fragile nutrients, chemically bonding them to carbon at the molecular level to stabilize everything. The static pack holds both vaporization (smells) and leaching (groundwater contamination) in check. Stopping the vaporization of manure is especially enjoyable because one of the most common nuisances around housed or sheltered livestock is noxious odors, which represent fertility and capital escaping from the farm.

Second, the deep bedding gives animals a warm, soft, comfortable lounging area. Concrete is as harmful to animals as it is to humans. Mud is even worse. Offering a clean lounge area bears health dividends to the flock or herd. Although the bedding pack isn’t warm to the touch, it never freezes. The anaerobic fermentation process creates enough heat that it stays well above freezing even when the ground is frozen.

Finally, deep bedding offers a medium for nematodes and other pathogen-fighting microbes to proliferate. This may be one of the biggest benefits because it speaks to the heart of the livestock housing problem: sickness. While bugs tend to have a negative inference in our culture, the truth is that most bugs (layman’s term for microscopic bacteria, fungi, and creepy-crawlies) are good. The trick is to provide a habitat that allows the good guys to beat the bad guys. I call this an “immunological terrain.”

For a healthy immunological terrain to exist, it must have mass, depth, and thickness. It can’t exist in thin landscapes any more than a softball-sized compost pile can exist. Herein lies the complication: Livestock housing facilities need to be designed so that bedding depth can be significant (from 12 to 48 inches) without compromising structural integrity. Sill plates, walls, feeding boxes, and everything else needs to be able to accommodate this bedding buildup. Not one in a hundred barns or farm buildings is designed to handle deep bedding, and this is arguably the single biggest farming travesty in rural America.

Species-Specific Feces

On our farm, we use different procedures for different animals. Ruminants eat hay out of hanging boxes that we can crank up with a hand winch (like curtains) as the bedding builds. We add corn to the bedding. When the cows come out to graze in the spring, we put in pigs, who seek the fermented corn and aerate the pile, converting it to aerobic compost. After the pigs finish, we spread the compost on the fields.

Because they can scratch, chickens don’t pack the bedding down like ruminants. Also, unlike cows, chickens aren’t as easy to chase outside while adding mid-winter carbon. Before the layers move into their tall tunnels for winter, we put in 12 to 18 inches of wood chips. That’s enough carbon to handle all their manure for the 100 days they’ll be inside, at a density of one bird per 3 square feet. We spread whole grains (wheat, barley, rye, and oats) on the bedding each day to stimulate scratching. Some of the grain sifts down into the bedding and sprouts, further encouraging the birds to scratch and seek out those tasty morsels. All this scratching and aeration yields a wonderful nutritious compost to spread on the fields in spring.

Pigs are a little different. Unlike herbivores and chickens, they pick a scat area. This means they root around the rest of the space, but leave that area undisturbed. When we give them junky hay or corn fodder, they eat half and strew and churn the other half into their unsoiled bedding. In spring, we mix the scat area with the nonfecal material, let it sit for about three weeks, and then spread it on the fields. The pig scat provides enough moisture, nitrogen, and microbes; the nonfecal area provides the air and carbon.

Throw a Manure Compost Shindig

During the bedding-building period, you can add minerals, wood ashes, or any other soil amendment you desire. The biological and enzymatic activity during the process will enhance the whole, creating a more potent fertility punch. Composting isn’t a separate process from everything else. Actually, designing composting into a housing or sheltering system takes much of the work out of the process and yields symbiotic returns.

Deep bedding creates efficiency because, instead of needing a routine clean-out, it only requires an annual clean-out. That transforms the clean-out from a chore into a shindig. Throw a party and invite your friends — tell them to bring pitchforks and wheelbarrows. It’s a time of celebration, of capturing wealth. What’s not to love?

Imagine if all the money spent on chemical fertilizers was spent on carbon for deep-bedding “carbonaceous diaper” systems across rural America. Imagine if diseased, invasive, and poor-quality trees were chipped, thereby healing and enhancing our forests. Imagine thousands of new jobs in the carbon sector replacing thousands of soldiers fighting for cheap petroleum. Imagine all the earthworms rejoicing over receiving compost rather than toxic chemicals! Let’s make this carbon-rich future a reality, and let’s start on-farm, in-barn, and, yes, with well-composted manure!