About the Manure Exchange Program
Clackamas Soil and Water Conservation District provides the Manure Exchange as a free service to benefit gardeners, farmers, and livestock owners. The Manure Exchange connects those wanting sources of local, free, manure/compost with livestock owners/managers who have more fresh or composted manure than they need.
This is a “no guarantees, use at your own risk” service. Manure and compost are generally not certified to be weed-free or organic. The material may not be suitable for all intended uses.
Providers are not responsible for hauling costs or any costs associated with vehicle/dump-truck rentals, etc. This is a voluntary, community project, so please be considerate of those participating in this service.
There are risks to using manure and compost
Invasive weed seeds can be a common contaminant in manure and compost. The number of weed seeds present in manure and compost depends greatly upon the livestock type, feed source, bedding material, and compost time. One publication found an average of “40 weed seeds per pound of fresh manure.” Another publication found that “nearly 25% of the seeds fed to hogs and cattle were recovered in the manure.”
Composting manure can dramatically reduce the number of weed seeds present, but this requires reaching and maintaining temperatures high enough to kill seeds. Many composting systems do not reach sufficient temperatures or do so inconsistently, allowing weed seeds to persist. We suggest that you test manure and compost to ensure that viable seeds are reduced before receiving or distributing manure/compost.
For more information:
There are risks to using manure and compost because some herbicides persist through the composting cycle. Those persistent herbicides may affect plants if the herbicides are in the manure/compost you apply. For more information:
- https://smallfarms.oregonstate.edu/sfn/f09Herbicide or read Herbicide Carryover in Hay, Manure, Compost, and Grass Clippings
Manure may carry animal diseases and viruses. Treat all areas of the site as if it were contaminated with bad bugs and take precautions not to expose yourself to them or carry them to another site. Identify and use an EPA-approved disinfectant:
Quality of material
The quality of animal waste products vary widely, depending on the source and how it was handled. Raw manure will likely contain pathogens and weed seeds. Antibiotics, dewormers, rocks, and other undesirable products may also be present. It is good to ask questions about the manure source, livestock feed, and other production details.
Is it fertilizer, compost, or mulch?
Nitrogen is an essential nutrient required by plants to grow. Raw manure is higher in nitrogen and other nutrients, but also presents more risk because of weeds and pathogens.
High-quality compost at the proper 30-to-1 carbon-to-nitrogen ratio will release nitrogen and other nutrients slowly to soil and plants; it is a relatively inert material and a great soil building amendment.
Finished compost made from parent material that was dominated by carbon such as wood chip bedding is better to use as a mulch cover to suppress weeds. Using a high-carbon, low-nitrogen material as compost will tend to rob the soil of nitrogen.
Links to composting resources
If you are seeking manure or compost, we strongly encourage you to talk with the provider about how they have managed the fields and feed sources for their animals. For example, learning that a broadleaf herbicide was recently used on a field that produced the hay that the animals consumed may affect your decision to accept the provider’s material.
How to test compost for herbicide residues
A commercial laboratory that tests for herbicides is Pacific Agricultural Laboratory. Contact them at https://pacaglab.com/ or 503-626-7943.
You can perform a simple bioassay at home:
- Fill three 3-inch pots with potting soil. Fill three more pots with a mixture of two parts compost and one part potting soil. Mark the pots.
- Plant three pea or bean seeds per pot and keep them watered. Capture any water that drains from the pots so it doesn’t contaminate soil in other pots.
- Put the pots in a sunny, warm place. Once the seedlings have three sets of leaves, compare the plants growing in the compost mix with the control group in potting soil. Unusual cupping, thickening, or distortion of leaves signals the possibility of herbicide contamination in the compost.
If you want manure or compost:
Please contact Tami Guttridge at (503) 210-6000 or [email protected]. Tami will collect information from you and attempt to find a match from our list of manure providers.
If you spread manure or incompletely composted material, avoid polluting water by spreading away from drainage ditches and waterways. Avoid spreading on water saturated soils as this can lead to soil compaction and contaminated runoff.
A manure spreading advisory can be found at: https://www.oregon.gov/ODA/programs/NaturalResources/Pages/MSA.aspx
Maintaining a grass buffer strip will also help prevent pollutants from entering surface water.
If you have extra manure or compost:
If you have extra manure or compost and wish to participate in the Manure Exchange Program, please use our Manure Provider Intake Form to submit basic information to the Clackamas Soil and Water Conservation District. By submitting this form, you give consent to Clackamas Soil and Water Conservation District to share the information with others for the purpose of exchanging manure/compost. To the extent allowed by law, Clackamas Soil and Water Conservation District will seek to keep your information confidential.
Other program pages:
- Equipment Rental Program
- Partner assistance
- Pesticide Stewardship Partnership
- Manure Exchange Program
- Video Series for Erosion Control Practices
- Residential Septic System Repair and Replacement Program
- Backyard Habitat Certification Program
- Horse Keeping and Land Management
- Technical assistance
- Conservation planning
- Invasive weed control