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Humic/Fulvic acids +Secondary & Micronutrient Recommendations

Humic Substances, are usually divided into three main fractions depending on their solubility in alkaline or acidic solutions.

  1. Humic acid is soluble in alkaline solution, but precipitates if acidified.
  2. Fulvic acid will stay in solution under basic and acid conditions.
  3. The Humin fraction is the insoluble part of Humic substances.  There is increasing evidence that the three fractions have similar chemical structures and properties but they differ in their molecular weight.

Fulvic acids are characterized by molecular weights between 3,000 and 20,000 grs/mol., but with higher content of oxygen-containing functional groups such as COOH- and OH- which yield a higher Cation Exchange Capacity, (CEC).  The ultimate structure of a Fulvic acid is unknown and extremely variable, although the major structural components and functional groups that determine many of its properties are known.

An elemental analysis of Fulvic acid will find a combination of six elements: Carbon, Hydrogen, Nitrogen, Potassium, Sulfur, and Oxygen.  The percent of active ingredient is increased by the increased percentages of Carbon and Oxygen.