Ask SAM: Composting turns manure into resource

This column is provided by Larimer County Extension's Small Acreage Management (SAM) Program to assist rural residents.

Dear SAM,

What is windrow composting and will it help me manage horse manure?

Cheryl G.

Dear Cheryl,

Properly managed, manure can become a valuable fertilizer and soil amendment.

A windrow is a long, narrow pile. To build a windrow compost, dump manure at one end of an open area. Deposit subsequent loads next to the previous load. You will be building a long pile that is old at one end and fresh at the other.

Turning and mixing your compost pile has many advantages. The manure and bedding will decompose more quickly as oxygen enters the pile. Turning also helps to control odors, as most of the foul smelling gases result from anaerobic decomposition that occurs when oxygen levels in the pile are low.

Mixing will also help to control flies and parasites, as eggs and larvae will be buried.

With sufficient oxygen, temperatures near the center of the windrow will reach about 145 degrees. When the temperature drops, it is time to turn the pile again.

The easiest way to turn the pile is with a bucket loader on a tractor. Scoop up a full bucket, lift and dump. If you don't have a tractor, a resident teenager with a pitchfork and a strong back can get the job done.

If you choose to not turn your compost pile, decomposition will still occur. But it will take considerably more time.

Moisture is also essential for composting. The bacteria and fungi involved in decomposition need water to survive and thrive. If rainfall is not sufficient, you might need to use a hose or sprinkler to keep the windrow moist.

The compost is done when it no longer heats up, even with sufficient moisture and oxygen. It should be uniformly dark brown with an earthy smell.

Composted manure can be safely applied to pastures. One horse produces enough manure to fertilize about two acres per year. If you exceed this rate, you risk contamination of soil and water with excess nitrogen and salts.

Composted manure can also be mixed with sand to improve your riding arena. Do not use uncomposted manure in arenas, as the ammonia from fresh manure can cause respiratory problems for your horse.

Gardens and lawn soils can be improved with the addition of compost. If you have excess compost, you might be able to find friends and neighbors to haul it away for their own lawns and gardens.

SAM

Have a question about rural living? Write to Ask SAM, Larimer County Cooperative Extension, P.O. Box 543, Fort Collins, CO 80522.