Composting Manure on Your Property

Managing Manure – Strategies for Collection, Storage & Disposal

Many landowners find raising animals an enjoyable part of owning a small acreage, but dread the unpleasant prospect of managing the resulting mountain of manure. Improperly managed manure provides a breeding ground for flies and other pests. Bacteria, fungi and mold from manure can cause disease and foot and respiratory illness in your animals. Nutrients and bacteria from manure harm fish and wildlife if they wash into streams. Manure also presents a potential source of pollution to local drinking water sources, such as a well.

Proper management includes regular collection, storage and disposal of livestock manure. Managing manure appropriately will reduce mud, reduce the volume of material by up to half, reduce parasites, pests and weeds and save time and money. Overall, proper manure management benefits your animals’ health, water quality and the general aesthetics of your property and potentially your family’s well being.

Collection

It is important to regularly collect manure every one to three days from turnouts, stalls and confinement areas. This prevents re-infestation from parasites since many worm species can hatch as frequently as every three days. It will also reduce mud since manure retains moisture and can become a
source of mucky organic material over time, creating an ideal breeding ground for flies, mosquitoes and other pests. Rainwater flowing through turnouts and confinement areas where manure is not collected picks up raw manure (with nutrients such as nitrogen and phosphorus) and sediment. This polluted runoff may then enter the nearest water body or drinking water source.

Storage

Once collected, you will need someplace to store manure until you are ready to dispose of it. When deciding where to locate manure storage there are three primary considerations: 1) whether you will compost the manure or use it fresh, 2) amount of space needed, and 3) where to locate the storage space.

Composting

Composting manure speeds up the natural decomposition process by creating an ideal environment for the microorganisms that break down the manure and bedding materials. The rate of decomposition depends on the size of the pile, amount and type of bedding material used and, how well the pile is maintained. Although composting manure requires more effort that just storing fresh manure, the benefits listed in Table 1 often outweigh the extra effort.

The ideal environment in your compost pile requires adequate moisture, oxygen, and a 25:1 ratio of carbon to nitrogen in the composting materials. Bedding materials such as straw, shavings, and sawdust are high in carbon.
If your livestock waste has a lot of bedding and very little manure or urine, the carbon to nitrogen ratio will be too high and the compost pile will take more time to break down. In this case, you may need to add some other materials that contain nitrogen, such as grass clippings, coffee grounds or vegetable wastes. These are commonly referred to as green materials and provide a good source of nitrogen to balance out the carbon rich bedding (Table 2). Vegetable scraps may attract pests like rats and mice. These types of nitrogen rich materials may be better suited to vermicomposting, or composting with worms. Meat, dairy products and other fatty food wastes should never be added to your compost pile. On the other hand, if you have mostly manure your mix will be high in nitrogen. Wood chips, fall leaves or other brown materials are good carbon sources which will balance out the carbon to nitrogen ratio (Table 2). Be sure to mix all the materials in well so they are evenly distributed.

Covering the compost pile keeps it from getting too damp in the winter and dried out in the summer. With all of the rain Clark County receives, it becomes double important to cover a compost pile since saturation can kill the micro-organisms in the pile and halt the composting process. Keep the pile as damp as a wet, wrung out sponge.

Microorganisms also require oxygen to decompose materials efficiently. Air can be added to the pile through turning, either by hand or using equipment, such as a tractor. To limit turning, place three or four PVC pipes with holes every 6 inches along the length in the middle of the pile. This helps get air into the middle of the pile as the pipes act like a chimney. Maintaining moisture and oxygen will help the pile heat up enough to kill parasites, pathogens and many weed seeds. The proper carbon to nitrogen ratio will ensure the micro-organisms decompose the manure and other materials to produce a valuable resource. Most problems such as bad odor, dry piles and slow decomposition result from issues with moisture, oxygen and the carbon to nitrogen ratio (Table 3).

Estimating Storage Needs

The number and types of livestock you have and the type of bedding material used will determine the amount of space required. A few brief calculations will help determine how much manure your animals produce and how much soiled bedding you will need to store. Table 4 provides the volume of manure produced by a 1,000 lb animal for various livestock types. Table 5 provides the volume of bedding per pound of bedding for four main bedding or footing material types. These tables, along with the example calculation below will assist you in estimating storage needs for a six month period.

Example

Below are sample calculations for manure and soiled bedding storage requirements in cubic feet (ft³) for four beef cows using straw bedding over a six month period.

Three bins about four feet high each will handle manure and bedding from the four beef cows over six months,

Location

Select a level, dry area to keep mud and runoff to a minimum and make chores easier. Observe where runoff moves across your property. Do not locate manure storage on sloped ground, in low or wet areas, or in drainage ways. Divert roof runoff away from manure storage. Swales, shallow vegetated ditches, or berms, small vegetated mounds of soil, are two methods for diverting rainwater around storage areas. Further information is available from the factsheet Improving Drainage. Consider distance to property lines, surface water and drinking water sources. Maintain at least 100 feet between manure storage and streams, wetlands and well heads. Maintain vegetated grass buffer strips to at least three to four inches in height around the storage area, to collect and filter runoff leaching from the piles. While properly maintained composting produces little odor, you might consider placing the compost bins downwind of homes and outside entertaining areas.

Based on the calculations and your chosen location, you can determine
what type of storage system will be needed for storing manure. The type
varies from the most simple, a pile with a weighted tarp, to a premium bin with a concrete pad and a roof with gutters and downspouts. A three-bin system is one of the most commonly used, as it allows the compost to be turned as it is moved from one bin to another. A three bin system also provides sufficient space to allow one pile in the compost process, another for fresh waste and a third for finished compost.

Compost bins can be constructed from landscape timbers which are treated to handle the elements or even from pallets, which can be obtained free from many sources. While pallets provide a flexible, convenient and inexpensive way to build a compost bin, they are not very durable and are unsuited for mechanical turning. Pallet bins can be assembled in any configuration and moved easily if needed and pallets are just the right size (usually 4 feet by 4
feet). Bins can also be constructed from concrete blocks and many other materials. If a tractor will be used for mechanical turning, make sure the walls of the storage bin are sufficiently strong. Plans for manure compost bins can be found on the web and at the WSU Clark County Extension office.

Disposal Options

Spreading composted manure on a pasture is one of the best ways to dispose of manure. Composted manure fertilizes and improves the structure of your soils, thus reducing fertilizer costs and minimizing runoff. The easiest way to spread manure on your pastures is to use a manure spreader. A tractor or strong riding lawnmower can pull a ground driven manure spreader. The Clark Conservation District has a manure spreader available for rent at low cost. Composted manure will have the greatest benefit when plants are actively growing from April to July. Limited volumes may be applied outside of this window if managed carefully to minimize runoff. Spreading compost on wet fields can also cause soil compaction. As a general rule, apply about ¼ inch at a time in three to four applications throughout the year. For more specific application recommendations, have your composted manure and
soil tested. Resources are available to help you determine which soils tests to conduct and how to interpret the results. Dragging the pasture with a harrow will help incorporate the compost or fresh manure more quickly. Harrows can be made from a section of chain link fencing or even an old bed spring.

If you have too much manure for the size of your fields, consider giving it away. Composted manure is often easier to give away or even sell than fresh manure. Posting an ad in the local newspapers or putting out a sign in front of the farm are two ways to advertise manure for free or sale. The Clark Conservation District also hosts a free manure exchange linking those with compost and/or manure with those who want compost or manure.  If you are interested in selling your compost, please contact Clark County Health Department Solid Waste Division about local regulations.

 

For more information on manure composting contact:

• WSU Clark County Extension – Small Acreage Program  (564) 397-5733/5729
• Clark Conservation District  (360) 857-4780
• Clark County Health Department Solid Waste Division  (564) 397-8428
• Clark County Master Composter/Recycler Program  (564) 397-7333

References
Blickle, A., J. Paige and E. Clark. 2001. Manure Management from Horses for Clean Water: A Guide to Environmentally Friendly Horsekeeping.

• Gaolach, B. Fact Sheet 539 – Strategies for Livestock Manure Management. King County: Washington State University King County Agriculture and Natural Resources.
• Pascoe, E. 1999. Horse Manure Strategies: Compost It! Practical Horseman. October 1999.
• Snohomish Conservation District. Alternative Bedding. n.d., 2 pp.
• Stephenson, G., Hannaway, D., Blickle, A., Brewer, L., Brewer, L. & Chaney, M. et al. Managing Small–Acreage Horse Farms. EC1558. Corvallis: Oregon State University Extension Service. March 2003,
• Washington County Soil and Water Conservation District. Manure Storage and Composting Facilities for Operations with Limited Numbers of Livestock. Portland, OR: USDA-NRCS & Washington County Soil

Extension programs are available to all without discrimination. Report evidence of noncompliance to your local Extension office.

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