Composting Horse Manure – Horsekeeping Mountain Style! #2

It just cannot be avoided – what goes in must come out.  One of our local horse folks has been successfully turning the manure from her two horses into a valuable resource.  Some work is involved, but not much more than what we already do.  At the end of the process you have nutrient rich compost while significantly cutting down on your overall landfill waste.  Composting reduces manure volume by half, stabilizes the nitrogen and phosphorus compounds to prevent water pollution; in addition to minimizing fly problems, odor, dust, parasite re-infection, spread of insect-borne diseases and fire danger.

To get started, location, pile size, and moisture content are key aspects to consider.  Find your location by establishing a small, warm, but not too windy area of your yard away from wells and water sources, but near the manure source.  The pile must be at least one cubic yard to be able to heat up enough to kill weed seeds and pathogens.  This person in our area decided to use three bins to allow each bin enough time to rest before new manure was added.  Another method is to make a windrow that is at least 3’ high and wide, shaped somewhat like a bread loaf and then the new manure is always added to the same end.  Finally, have a water source in reach in order to keep the water content around fifty percent, or about the consistency of a wrung out sponge.  Too much moisture emits an unpleasant odor and too little does not allow for proper decomposition.  Ann also had some ant issues when the pile became too dry.

In addition to manure, which is considered a “green” component rich in nitrogen, “brown” components rich in carbon are required to make compost.  “Brown” materials include dried leaves, straw, sawdust/shavings, waste hay/feed and dried grass clippings.  Other sources of “green” or nitrogen rich materials are green leaves, fresh grass clippings, green plant waste, and fruit/vegetable waste from the kitchen.  The best carbon to nitrogen ratio for compost is 25-30 parts carbon to one part nitrogen.  Layering the native soil with the green and brown components adds in the natural microorganisms needed to decompose the compost pile.

In addition to the moisture and materials, heat and air are essential.  When your pile is the proper size and moisture content, the core of the pile will reach a temperature of 140 degrees F.  Once that temperature is reached and then decreases, it is time to turn and aerate the pile in order to oxygenate and mix the materials.  Our local has been using a pitch fork to aerate and/or turn the piles or you can of course use heavier equipment if available.

The temperature will rise and fall several times in the process.  You can also add ventilation pipes through the bottom of the pile to allow passive aeration.  Once the compost pile temperature stabilizes, the composting is ready to cure.

Curing is done by the mid-temperature microorganisms and takes 1-2 months.  For curing, keep the pile moist, but not over 50% moisture.  During curing the pH returns to neutral, the soils natural microorganism’s recolonize and give disease suppressing qualities.  The result is homogenous, humus-like, dark compost with that deep, earthy aroma.

The end product can be added to your pasture, lawn, garden, tree and shrub soil to increase organic matter, fertility and water holding capacity – all qualities that we need in our rocky soil!  It can also be used as stall bedding or turn a profit by selling to landscapers – Instead of poop in the pasture, you will see dollar signs!  Start composting your horse and organic waste and learn a new way to manage your manure and care for the earth’s land and resources – make a pile and just keep in mind the general principles of composting:  moisture, materials, heat and air.

Other things to consider in our climate:  In the winter, tarps or plastic can be utilized over the pile to hold in the heat and moisture.  The smaller the pieces that are added to the compost pile, the quicker the process.

A plug for worms (red wigglers or red worms in particular) – Vermicomposting or using worms to compost has great perks including year-round composting, expedited composting process, no aeration required because the worms do the work, the compost tea they produce is a great liquid fertilizer and they make easy to care for, hardworking family pets.

For more composting information go to the Colorado State Extension Service and

Heather McWilliams © 2013.