Humic acid vs fulvic acid
A neutral comparison of humic acid and fulvic acid as distinct fractions of humic substances, including solubility behaviour, common contexts and buyer questions.
Humic acid and fulvic acid are related but distinct fractions of humic substances. The most useful first distinction is their traditional pH-dependent solubility behaviour, not a claim that one is universally better than the other.
| Question | Humic Acid | Fulvic Acid |
|---|---|---|
| Place within the category | A major fraction of humic substances. | A related fraction of humic substances, generally described in lower molecular weight terms. |
| Solubility behaviour | Soluble under alkaline conditions and tends to precipitate under acidic conditions. | Generally remains soluble across the full pH range used to distinguish the fractions. |
| Common industry context | Soil conditioning and fertilizer discussions. | Foliar and fertigation discussions for soluble grades. |
| What a buyer should verify | Source, grade, physical form, analytical method and batch COA. | How content is defined, the form supplied, analytical method and batch COA. |
How to use the distinction
Start with the application and documentation
The same label can cover materials from different sources and grades. Match the physical form and stated application context to the programme, then compare the specification and COA using the same analytical method where possible.
- 01Define whether the material is intended for soil, foliar, fertigation or another programme.
- 02Confirm how humic or fulvic content is defined and tested.
- 03Review form, pH, solubility, moisture and source information.
- 04Request the batch Certificate of Analysis before making a sourcing decision.