The Magic of Manure Compost: Protect Your Waterways, Save Money, and Improve Your Soil!

When you think of San Diego County, horses aren’t usually the first thing that come to mind, but we do have the second-largest number of horses in the state (only Riverside County has more).  As beautiful as they are, there are few ways to turn money into manure faster than having a horse. Horses can create up to 50 pounds of manure per day! Horse owners have the unique problem of having to dispose of this manure and composting is an easy and economical way to do it.

As many of you know, compost can be used as an amendment to create healthier soil which in turn leads to healthier plants. Compost improves soil aeration, water retention, and provides beneficial slow-released nutrients to your plants. It also introduces beneficial bacteria and supports a healthy soil food web. 

Benefits of Manure Composting

• Kill weed seeds, parasites and pathogens – When temperatures of 131 degrees (Fahrenheit) are reached within your compost pile, harmful pathogens like E.coli and salmonella are destroyed along with any weed seeds and many medications given to your livestock. This is very important especially if you’ll be using the finished compost on your garden or pastures where animals graze.
• Reduce flies– The temperatures reached by a well-managed compost pile will also kill fly eggs and larvae; and with less manure around there will be less breeding grounds to attract those flies that pester both you and your livestock.
• Less odors and a smaller pile – The composting process reduces bulk by about 50%, that means you’ll have less material to deal with, more space available, and composted manure has far less odor than uncomposted manure.
• Save money and help the environment– Composting onsite eliminates the need for manure to be hauled away which, in addition to being costly, unnecessarily fills up precious space in our landfills where it can release harmful methane gas. For example, Patty Morton, owner of Pathfinder Farms in San Marcos, was paying $430 per month in hauling fees to dispose of the manure produced by 25 horses on her property. Now, she can save that money, has great compost for her landscaping, all while diverting waste from the landfill.
• Natural fertilizer – Utilizing finished compost on your plants creates additional cost savings– you won’t have to purchase synthetic fertilizers or amendments to provide nutrients to your landscape or garden. Why not put that manure to good use and save money in the process!? Composted manure creates a final product that is an outstanding soil amendment and mulch that can be used in gardens, pastures, and the landscape.
• Follow the rules – According to California’s Commercial Recycling Bill AB 341, which went into effect July 2012, commercial horse ventures generating four or more cubic yards of solid waste per week need to arrange for it to be recycled, reused, composted or otherwise diverted from the waste stream. Again, composting solves the problem.
• Protect your waterways – Unfortunately, all of San Diego waterways have higher levels of bacteria than the state allows. Manure is not wholly to blame, of course, but it does contain bacteria that contribute significantly to polluting our waterways if not managed properly. Properly composted manure reduces the possibility of contaminated runoff leaving a horse property. (Learn more about protecting your waterways and landscape here.)The use of finished compost on landscaping and gardens means less reliance on synthetic fertilizers and pesticides that can also harm our waterways.

Fundamentals of a Successful Manure Composting System

• Location: A flat surface is ideal so any run-off from fresh manure will not reach waterways.
• Compostables: Manure is not the only component you’ll be adding to the compost pile. Any natural bedding material, like straw or untreated shavings, are a wonderful carbon-rich addition to the compost pile. Urine is also a great source of nitrogen so throw it all in! You can even add grass clippings and yard trimmings, but just be careful about adding your kitchen scraps (veggies and fruits) since that might interest local pests.
• Access to water: Just like in traditional composting, manure piles should maintain a moisture level equivalent to a wrung-out sponge (not sopping wet, but damp). Make sure there is a hose nearby so you can add water as needed.
• Aeration: The decomposers responsible for making manure into beautiful finished compost need oxygen just like you and I do. Make sure to turn the pile about once a week in order to aerate it, and also mix materials. Depending on the size of the pile you can do this with a compost fork, or a shovel, or if you have a lot of material, a backhoe or tractor might be ideal.
• Size: Piles should not be more than 5 feet high and 5 feet wide but they can be elongated in a windrow fashion to accommodate a lot of material.
• Temperature: In order to destroy any harmful pathogens a temperature of 131 degrees Fahrenheit should be reached in the core of the pile. You can make sure you reach this temperature by purchasing a compost thermometer. Do not allow the pile to reach temperatures higher than 160 degrees since at that point you kill off beneficial bacteria. If you notice your temperatures are getting too high, turn the pile. This allows it to cool down, and also does the important job of getting external material into the insulated core where necessary temperatures will be reached to kill pathogens. If you’re having trouble reaching 131 degrees, try adding some nitrogen-rich materials like cut grass, coffee grounds, or chicken manure, and make sure your pile is moist enough.

Composting has many more rewards beyond keeping your horses healthy. But don’t take our word for it, just ask your NEIGHbors…

If you want more information about how to compost manure, keep an eye on the Solana Center’s event calendar for our next Free Manure Management Workshop. These are held twice a year. If you own a ranch or farm and would like to host us, don’t hesitate to reach out!

You can also watch this brief and fun video, hosted by Sam the Cooking Guy, and provided by the County of San Diego, that shows you the basics of composting with manure.