The North American Proficiency Testing Program (NAPT) of Soil Science Society of America
The National Forage Testing Association (NFTA)
Washington State Department of Ecology (DOE)
Washington State Department of Health (DOH)
U.S. Environmental Protection Agency
Title 1: “Sampling Hay, Silage, and Total Mixed Rations for Analysis”
http://litchlab.tripod.com/docs/ForageSamplingProcedure.pdf
Title 2: “Guides for Soil Sampling”
http://extensionpublications.unl.edu/assets/pdf/g1740.pdf
Title 3: Nutrient Management Guide for Dryland and Irrigated Alfalfa in the Inland Northwest
Title 4: “Northern Idaho Fertilizer Guide, Grass Pastures”
https://www.extension.uidaho.edu/publishing/pdf/CIS/CIS0853.pdf
Title 5: “Acidifying Soil for Crop Production: Inland Pacific Northwest”
https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/pnw599.pdf
Dairy One Links:
Title 6: “Making the Most of Forage Sampling”
Title 7: “Collecting a Forage Sample”
Title 8: “Understanding & Significance of Forage Analysis Results”