Spreading compost in late fall or during winter doesn’t do any good because the grass plants are dormant and soils are either frozen or saturated.  Also, spreading during the dormant season means nutrients may go to waste and potentially wash away in winter rains, contributing to water pollution.

A Few Things to Keep in Mind

Spread a ¼- to ½-inch layer at a time and no more than about 3 to 4 inches in the same area per season. This avoids smothering pasture plants or putting out more nutrients than a plant can use. Realistically, when you spread compost it is rarely going to look like a thin, even layer but more like clumps here and there. 

Compost can be spread by hand or with a manure spreader. Hand spreading is a good option if you’re spreading on two acres or less with one or two horses. It isn’t as hard as it sounds and can be done with a wheelbarrow and shovel. Simply transport your compost to the area of your pasture where you want to spread and toss away. Be sure to crumble up any large clods as you toss them so that plants can break down nutrients and organic materials more easily. 

If you are considering purchasing a manure spreader, keep in mind that there are two basic categories: ground-driven and PTO-driven. Ground-driven means that as the wheels turn, the manure spreader the belt that powers the beater bars turns and throws out the compost. A ground-driven manure spreader can usually be pulled by an 18 horsepower (or larger) riding lawnmower, a small four wheel-drive pickup, or even an ATV.  PTO- (power take-off) driven means that the PTO on your tractor will power the drive unit on the spreader. If you choose to go with a PTO-driven model then you’ll obviously need to have access to a tractor with a PTO (not all tractors have one).  You will also need to be sure your tractor is sized to handle the spreader you purchase.

You May Not Have to Buy

Contact your local conservation district to see if they have a manure spreader that they loan out.  If you are not familiar with conservation districts, they are non-regulatory, non-enforcement agencies that provide education and technical assistance on natural resource issues.  There is one in every county in the United States.  Many of these districts “own” a manure spreader that they loan out for free to landowners to help them spread compost.  Contact your conservation district to find out if they have such a program. For more information on contacting conservation districts in Washington State see the Horses for Clean Water website at www.horsesforcleanwater.com.

One more thing about manure spreaders: be sure they are adapted for horse manure or composted horse manure and not cow manure. Cow manure is softer and more "pie-shaped," which often makes a difference in how the tines in the spreader are structured.

Compost is a rich soil enhancement that improves the health of both plants and soil and helps retain moisture. It contains micro and macronutrients that benefit plants, and it adds important organic material to your soil.  If you have horse manure that hasn’t been actively composted, you can spread that also, but composted horse manure is much more desirable.  Composting kills the pathogens and parasites in manure.  When you spread raw manure on pastures, you increase the risk that your horse will ingest the parasites that live in manure.   So if your manure isn’t composted yet, you may want to let it compost over the winter and spread it next spring.  For more information on composting, see the Horses for Clean Water Tip Sheet, 5 Easy Steps to Compost, at www.horsesforcleanwater.com.

Good horsekeeping to you!