Technical information for better comparisons
A technical hub for humic substance specifications, COA review, testing, solubility, grades, physical forms and terminology.
How humic products are specified
Compare fields and methods together. Two values may not be like-for-like when the analytical method differs.
- Humic acid contentCheck the reported value and the analytical method used to derive it.
- Fulvic acid contentMay be reported separately where relevant to the material.
- Moisture contentAffects effective concentration in solid forms.
- pH and solubilityIndicate handling behaviour and mixing conditions.
- Ash or mineral contentRelates to inorganic residue in the material.
- Particle size or meshRelevant to dust, dissolving speed and application.
- Source materialLeonardite, lignite, peat or other sources can influence composition.
A specification is not a batch result
A Certificate of Analysis reports what a specific batch tested at. Read it beside the product specification, with the test method and date in view.
Methods belong beside values
When comparing products, identify how humic and fulvic content, moisture, pH, solubility or other parameters were measured. A headline figure without its method is incomplete technical information.
Read solubility in context
Humic acid is traditionally described as soluble under alkaline conditions and tending to precipitate under acidic conditions, while fulvic acid is generally described as soluble across the full pH range. Commercial handling still depends on the product, grade and formulation.
Physical form affects handling
| Form | Handling | Common context | Question to ask |
|---|---|---|---|
| Powder | Fine and dusty; care is needed when mixing | Soil incorporation or solubilised blends | What dust control and dissolution are needed? |
| Granules | Free-flowing and generally lower dust | Broadcast or spreader-applied | What spreading and dispersion behaviour is needed? |
| Flakes | Flaked solids with moderate dust | Dissolving into stock solutions | How quickly and consistently should it disperse? |
| Liquid | Ready-to-dose concentrate | Fertigation, foliar or tank mixes | What concentration and compatibility are specified? |
Terms used across the reference
- Humic substances
- The wider category of complex organic matter that is commonly discussed through humic acid, fulvic acid and humin fractions.
- Humic acid
- A fraction traditionally described as soluble in alkaline conditions and precipitating under acidic conditions.
- Fulvic acid
- A related fraction generally described as remaining soluble across the full pH range.
- Humate
- A salt or commercial form associated with humic acid, such as potassium humate or sodium humate.
- COA
- A Certificate of Analysis reporting what a specific batch tested at.
- Specification
- A description of what a product is expected to meet; it is not the same as a batch result.