A 5-Step Guide to Composting Horse Manure

We compost on our guest ranch, Sweet Pepper Ranch. In southwestern Idaho a tarp cover helps keep the compost from getting too dried out in the summer or too soggy in the winter. | Photo: Alayne Blickle

If you care for horses on your own place then you have, no doubt, wondered about what to do with that huge mound of manure and stall waste generated by your horse. In fact, one horse produces about 50 pounds of manure per day, over eight tons per year! Add to that the bedding you use each day and in no time at all you have a virtual manure mountain!

There are other concerns related to a mismanaged manure pile: horses allowed to graze near their own manure are quickly reinfested with worms, runoff from soggy manure piles can cause serious surface water contamination problems, and then there are the associated odor and fly problems. Composting horse manure is an excellent manure management technique which has these benefits:

•  The composting process reduces the size of your manure pile by about 50 percent!
•  Heat generated by composting kills worm eggs, fly larvae, pathogens and weed seeds.
•  Composting reduces flies, runoff and odors.
•  Composted manure is a valuable addition to your pastures, garden, or yard. And, if you can’t use it on your own property, “horseless” neighbors are usually glad to take it.

We compost on our guest ranch, Sweet Pepper Ranch, here in southwestern Idaho. It’s not a complicated process. Just follow the five steps below and you’ll find that pile of manure behind your barn will quickly turn into black gold!

#1 Select a Site

First, select a site for your manure pile. Look for a high, level area on your property; don’t put your pile in a low lying area or it will turn into a soggy mess during the rainy season. Choose an area away from property lines to avoid zoning issues and problems with neighbors. A location that’s convenient to your stall and paddock areas will make the chore time easier and less time consuming.

#2 Build Bins or Piles

Constructing bins or piles helps the composting process by allowing you to construct a pile that’s at least three cubic feet it size (about the size of a washing machine) which is what a pile needs to build heat. If a pile is too low and spread out it’s much harder for the pile to heat up and compost effectively. Construct your compost bins so they are at least 8’x8’x5′, about the amount of space you’d need to store six months of straight manure (no bedding) from one horse.  If you have a tractor, you may wish to just build pile. We have a roofed structure we use to compost under, and, at least for now, I like the flexibility of not have a permanent compost structure so we can change where we want things to be located as we need it.

You’ll probably need at least two bins (or piles if you have a tractor), maybe a third for convenience. A two-bin/pile system works by piling manure and stall wastes in one bin/pile. When that bin is full, allow it to compost and start filling the second binÑor building a second pile. Once the first bin/pile is done composting you can start removing and using the finished compost. For convenience or if you have three or more horses, you may want to consider going to more bins/piles. This allows for one bin for daily wastes, another bin which is full and in the composting stage and the third for the finished compost to be removed and used at your leisure.

#3 Tarp Your Bins or Piles!

Get composting now so you’ll have something for those tomato plants this spring! | Photo: Alayne Blickle

One of the most important things to do in order to have a successful compost system is to cover each of your compost piles with a tarp. This will prevent your pile from becoming a soggy mess in the winter and too dried out in the summer. A tarp also prevents the nutrients you’re saving for your pastures or garden from being washed out into the surface water and causing pollution problems.

#4 Get Air into the Pile

Turning your compost-to-be gets air into the center of the pile and will speed up the composting process, allowing the pile to compost evenly from the inside out. However, unless you have access to a small tractor or enjoy a good workout, turning by hand can be difficult. An easier way to get air to the center of the pile is to insert a couple of five-foot PVC pipes into the center of the pile with the ends sticking out of the pile like chimneys. To increase the effectiveness of the pipes, drill holes a few inches apart along the pipes.

#5 Keep the Pile Damp but not Soggy

Your compost material should be about as damp as a wrung out spongeÑit should feel damp but not dripping with water. If you squeeze a handful of it in your hand, you should only be able to squeeze out a drop or two. In the summer, you may need to hose down the manure in your wheelbarrow before you dump it in the pile.

The Finished Product

Composting generally takes between three to six months.You will know when your compost is ready when the material looks evenly textured and crumbly like dirt. So get busy composting now so you’ll have something for those tomato plants this spring!

Alayne