A New Standardized Method for Measuring Humic and Fulvic Acid Concentrations in Commercial Products.
Richard T. Lamar, Horizon Ag, Louisville, CO, Daniel C. Olk, National Laboratory for Agriculture and the Environment, USDA-ARS, Ames, IA, US, Lawrence Mayhew, Eco Agri-Minerals, Spring Green, WI and Paul R. Bloom, 1991 Upper Buford Cir., University of Minnesota-Twin Cities, St. Paul, MN