Submitting Compost Samples for Analysis
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. Label sample bag with sample ID.
For submitting samples to our lab, bags are available at your local Extension office or use a quart sized plastic bag.