Obtaining a representative sample is critical for getting a good estimate of nutrient value.
The sample submitted must be representative of the compost to be used if the analysis is to be of value. The number of sub-samples will depend on the size of the pile, but in general, take 1-pint sub-sample sizes from at least 5 places around the pile. At each place, sample 3 different depths. Take one at the surface, take the second midway between the surface and the core, and take the third at the core. Mix all of these sub-samples thoroughly in a clean 5 gallon plastic bucket. For your sample, fill the sample bag with 1 pint of this mixture. If bulk density is required, 2 quarts of this mixture must be submitted.
Fill out one form per sample. (Go back to the 'how to complete forms' link for more information.)
For submitting samples to our lab, bags are available at your local Extension office or use a quart sized plastic bag.