Applications: Nurseries, greenhouses, commercial compost producers.
Price: $100 / sample
Forms & Instructions: Submission Form
A standard compost analysis package will yield information on the nutrient content of the material including total P, K, Ca, Mg, B, Cu, Fe, Mn, S, Zn as well as total N and nitrate-N. In addition the standard test includes total carbon and the calculation of the C:N ratio, soluble salt content, organic matter and ash content as well as percent solids. Additionally, upon request samples can be analyzed for ammonium-N, physical contaminants, particle size, bulk density, CaCO3 equivalent, heavy metals and physical analysis by ASTM D422. The UW lab cannot analyze samples for pathogens, seed content, organic acids or mercury.
Analysis and Reporting
The results are intended for informational purposes only and are not to be considered as meeting the S100 compost specifications or any testing assurance programs.
You must collect a representative sample of your compost. Compost piles or windrows can be quite variable in composition. Thus, you need a composite sample of material collected from at least 5 locations and 3 depths at each location and separate composite samples for different piles.
- Use a clean spade/trowel, a clean 5 gal plastic bucket, a clean plastic tarp and a 1-2 quart sample container (freezer zip-loc bag, or wide-mouth plastic bottle).
- At each location, collect about a pint of material from near the surface, another pint midway to the center, and another pint from near the center placing them in the bucket.
- Repeat the process at each sampling location, adding the samples to the bucket.
- When you are done with all locations, thoroughly mix the material in the bucket or on the tarp until you have a homogeneous mix.
- Collect 1 to 2 quarts of mix into the zip lock bag or wide mouth bottle. Label the container to identify the sample.
Complete the submission form and drop the sample off at our facility or mail the sample, the form, and payment for the value of the analyses requested.
If you mail the sample, please make sure it can arrive at our facility within 48 hours.