Source: Maryland Department of Agriculture Office of Resource Conservation

A 1,000 pound horse produces 40-50 pounds of manure every day! Everyone who owns horses has a responsibility to protect local streams from manure runoff. Here are some best management practices that all horse operations—large and small—can use to keep manure and its nutrients out of waterways.

Do not store piles of manure in places where runoff or floodwaters may wash it away. Place a cover or tarp over the pile to keep out rainwater. Consider building a manure storage structure. These structures protect stockpiled manure from rainwater runoff until it can be used safely as a fertilizer.

Manure storage structures usually consist of a concrete pad to protect groundwater and a wall on three sides to make handling easier. Soil conservation districts provide free technical assistance to design manure storage structures. Depending on the size of your operation, cost-share funds may also be available. Contact your local soil conservation district for information. (See for SCD contact information and websites)

There are many benefits to setting up a small composting facility for your horse manure. Composted manure makes an excellent pasture and garden fertilizer as long as it’s not spread too heavily. It can also be combined with yard wastes and non-meat kitchen scraps. Contact your local Extension office or soil conservation district for assistance in setting up a compost system that works for you.

• Begin by building a pile of manure and stall waste that is at least 3 ft. x 3 ft. x 3 ft.
• Cover the pile with a roof, tarp, or sheet of plastic. A cover keeps the pile from getting too wet in the winter and too dry in the summer.
• Keep the pile as damp as a wrung out sponge—no wetter or drier!
• Add air to the pile. Turn by pitchfork, with a tractor, or by inserting a few PVC pipes into the center of the pile like chimneys to increase airflow.
• When the pile gets as big as you can manage comfortably, start a second pile and allow the first to continue composting.
• Add garden waste and lawn clippings to your compost. Don’t let grass clippings clump together—spread clippings out to allow airflow.
• Use only herbivore manure in your composting system. Do not use dog and cat feces that may contain pathogens.
• Don’t place your composting structure where surface water can reach it.

Is it Finished?
Your compost should be ready to use in two to three months in summer. It will take longer to decompose in winter. You will know that your compost is ready when the pile is half its original size and the material looks and feels like fertile garden soil.

• Your compost system should smell earthy, not unpleasant.
• Compost should be moist and crumbly. Properly composted manure kills internal parasites.
• Once manure is composting, odors and flies should not be present.
• If your compost is not heating up or has a bad odor, check to see if it is too wet or too dry and turn the pile more frequently.

• Collect raw manure from sacrifice lot and stalls every 1-2 days.
• Apply the compost according to your nutrient management plan or University of Maryland Extension recommendations.
• Do not apply fresh, uncomposted stall waste directly to your fields.
• Any bedding material, including sawdust/shavings, can be composted. Your local Extension office can provide the correct recipe.
• Don’t let that manure become a mountain!

• Be a good neighbor—manure problems can be very unpleasant
for neighbors.
• Manure creates a breeding ground for insects, especially filth flies.
• Internal parasites hatch from manure as often as every three days.
• Manure left on the ground and in the loafing area creates conditions that may cause health problems for horses.
• Runoff from manure piles is a major source of nutrient pollution entering the Cheasapeake Bay and its tributaries.