Spotlight on Aerated Composting

Making Compost Happen the Quick and Chore-Efficient Way

by Peter Moon

Horse owners of every variety face a daunting challenge when it comes to manure management. Without a good system, the volume of manure and spent bedding can become overwhelming.

“A 1,100-pound horse passes manure, on average, seven to ten times per day, adding up to a total daily output of about fifty pounds. A small operation housing only ten horses accumulates almost seven tons of manure in just one month. And that’s just the manure. The muck pile also contains soiled, urine-soaked and wasted stall bedding, which—depending on what type of bedding you use—can double or even triple the volume and weight of stuff that goes onto the pile” (The Perfect Stall Project, Karen E. N. Hayes, DVM, MS.)

However, the volume of manure and waste bedding isn’t the real problem. Unmanaged manure is a source of flies and offensive odors; it results in mud (hoof problems) during the winter months and ammonia and dust (respiratory problems) during the summer; and is in general an unsightly mess. In numerous ways, unmanaged manure adversely impacts our horses’ health and it degrades surface and ground water quality along with aquatic life. This is why federal, state and local regulatory agencies are now taking a much closer look at horse farms nationwide as a significant cause of non-point source pollution. As a result, reasoning such as, ’But I’ve been doing it this way for 30-years’ is no longer an acceptable excuse for doing nothing to solve the major environmental problem. There are no exemptions—we’re in this together.

Composting is a Win-Win...Win, Win, Win Opportunity for All Concerned.

So what constitutes a good manure management system? Alternatives to unmanaged manure piles generally include either: 1) off-site disposal; 2) direct land application; or 3) composting. In some instances, a deal can be struck with a local farmer to take the manure waste for applying in his own fields. In such situations, you are subject to the whims of the farmer and with just a phone call can suddenly be left with no alternatives. In other words, you do not control your own destiny when you rely on others to resolve your problems.

More often, however, off-site disposal is a fee-for-service arrangement with a waste hauling company and it involves a dumpster or roll off container that is inevitably situated in a main traffic area (i.e., front and center) where the truck can back in to load and unload. Containers, unfortunately, are seldom aesthetically pleasing which detracts from the overall look and feel of the farm. Because waste hauling is typically a franchise business, you will pay the going rate, whatever that might be. And keep in mind: rates never go down.

Direct land application has its appeal, especially in situations where few horses are situated on a large land base. However, direct application of raw manure to pastures frequently results in an endless cycling of parasites, pathogens and invasive weeds that impact your horses’ health. “Even a healthy horse passes millions of potential pathogens in its manure—bacteria, protozoa, fungi, and parasites.” (How to Be the Perfect Horsekeeper, Karen E. N. Hayes, DVM, MS, Iron Horse Publishing, 2005.)

Composting, on the other hand, converts raw horse manure into a clean, high-value product that can be effectively used around the farm or sold for profit. Horse manure compost is an excellent source of macro- and micro-nutrients as well as stable organic matter, all of which support healthy plant growth. Compost also retains water extremely well resulting in improved drought resistance, a longer growing season and reduced soil erosion.

The key is to make the composting process as efficient and systematic as possible—to make it a fully integrated, daily part of your farm routine.

Finding a Compost System That Works for You

In the past, composting has generally been accomplished using the PhD Method (Piled Higher and Deeper). For many farms, particularly those with more than a couple of horses, this can turn into a 1- to 2-year process. Turning a manure pile (manually or with the use of a tractor) is often used to add air to the pile and speed up the composting process. Most people think that this turning will fluff the material and reintroduce oxygen into the core. What is not understood is that the infused oxygen is consumed by the microorganisms within 30 to 45 minutes, thereby yielding an anaerobic compost pile despite the expended time and effort.

Turning can also be time-consuming and hard to integrate as part of a daily routine. People who subscribe to this method of composting mostly intend to turn the pile but with the pace of life in our modern age, this seldom actually takes place once the “fun” part of composting has waned.

Aerated Static Pile composting allows you to add air to the pile without the extra labor that turning requires. The system utilizes an electric blower to induce airflow through the pile and thereby help the pile “breathe.” A timer operates the blower so that the blower cycles on for 3 to 4-minutes and then turns off for 20 to 30 minutes. The blower is set to cycle in this manner 24 hours a day, 7 days a week, and within 21-30 days, the primary phase of composting is nearly complete. This initial stage is referred to as the active phase of composting. As with wine, compost gets better with age. Following the active phase, the material transitions into fungal driven process referred to as curing. It is during the curing phase that most of the textural change to the mix occurs; yielding a uniform, dark soil-like product that smells nice and has “magical qualities,” according to avid gardeners.

The oxygen stimulates the microorganisms and their by-product is heat. In a properly operated compost system, pile temperatures are sufficient to pasteurize the raw material and the oxygen rich conditions within the core of the pile eliminate offensive odors. High temperatures also serve to destroy fly larvae and weed seeds. Finally, aeration greatly speeds up the composting process and lends itself to a true flow-through process, thereby eliminating the “2-year pile syndrome.”. Again, all of this takes place without having to turn the compost pile.

Education—Not Legislation

As horse owners, it is our responsibility: to properly manage the manure and waste bedding that is generated on our farms; to protect our water resources; and to protect the health of our horses. Each of us impacts the world we live in—that is a given. It is up to us to choose whether our collective impact will be positive or negative—that is the decision that we need to make for ourselves before the decision is made for us. It is not a matter of if, but rather a matter of when.

The secret to proper horse manure management is composting. The secret to composting is to find a system that is easy and easily integrated into your daily routine. To learn more about Aerated Static Pile Composting, visit the O2 Compost web site.

About Peter Moon, P.E. Peter Moon is President and Principal Engineer of PME/O2Compost, and is a licensed Professional Engineer in the State of Washington. Peter has a Bachelor’s Degree in Geology and a Masters of Science in Geotechnical Engineering from U.C. Berkeley. He has 25 years of consulting (i.e., problem solving) experience. Prior to 1989, Peter had never even heard the word composting, let alone study the subject in school. However, during the past 15 years Peter has learned a great deal about composting and everything he knows he has learned by doing it. Having studied, tested and resolved nearly every mistake imaginable, he understands what works and more importantly what does not work. His hands-on experience has led to a career in training others the How-To’s of on-farm composting.