Molecular Structure of Humic Acid

Humic acids are not fertilizers; they are chemically and structurally different from chemical fertilizers and should never be compared or classified as a fertilizer. Humic acid molecules are long chains composed of mostly carbon oxygen and hydrogen. They are not the product of an acid base reaction and are not crystalline structures. They are complex molecules that do not ionize in water and have little if any salt index. I have never seen any measure of humic acid for salt index because they don’t function like a salt. I would guess that it would be less than 0.1% if you could measure it at all.

Most chemical fertilizers are usually two elements or polyatomic ions bonded singularly, creating a salt. Example table salt, sodium chloride, Na+ and Cl? form NaCl in a crystalline shape.

Here are some definitions for you:

Salt Index - An index used to compare solubility of chemical compounds. Most nitrogen and potash fertilizers have high indexes, and phosphate compounds have low indexes. When applied too close to seed or on foliage, the compounds with high indexes cause plants to wilt and die.

Salt - The products, other than water, of the reaction of an acid with a base. Salts are commonly found in soils break up into cations (positively charged particles like calcium, sodium, potassium, etc.) and anions (negatively charged particles like chloride, sulfates, nitrates, etc.) when dissolved in water.