For example, if 10 percent of the manure differs from the bulk pile, then 10 percent of the total sample should be taken from this area. The collected material should be combined in a plastic container and mixed thoroughly. The 1-quart laboratory sample should be taken from this mixture, placed in a plastic bag, sealed, and shipped to the laboratory for analysis. If the sample can not be shipped within one day of sampling, it should be refrigerated. The weathered exterior of uncovered waste may not accurately represent the majority of the material.
Rainfall generally moves water-soluble nutrients down into the pile.
If an unprotected stockpile is used over an extended period, it should be sampled before each application. Stockpiled waste should be sampled at a depth of at least 18 inches at six or more locations. The collected material should be combined in a plastic container and mixed thoroughly. The one-quart laboratory sample should be taken from this mixture, placed in a plastic bag, sealed, and shipped to the laboratory for analysis. If the sample cannot be shipped within two days of sampling, it should be refrigerated.