Humic acid, humates and fulvic acid are used on farms as soil conditioners, as additives in fertilizers and in irrigation and foliar programmes. This page explains how they are used and which of our grades fit each use.
How humic substances are used in farming
Nutrient retention
Humic acid has a high cation exchange capacity, so it can hold ammonium and potassium ions in the root zone.
Phosphate fertilizers
Humates are added to phosphate fertilizers such as DAP and MAP; they are reported to help keep phosphorus available to plants.
Soil structure
Humic acid can help soil particles form aggregates and can help the soil hold water.
Soil pH
As a weak acid with buffering capacity, humic acid can help moderate soil pH.
Products and forms for farming
| Use | Products | Forms |
|---|---|---|
| Soil conditioners and base fertilizers | Humic Acid, Potassium Humate, humate granules | Powder, granules |
| Compound and NPK fertilizer blending | Potassium Humate (often mixed with urea, DAP or MAP), Humic Acid, Nitro Humic Acid | Powder, flake, granules |
| Water-soluble and drip-irrigation fertilizers | Super Potassium Humate, Fulvic Acid, Potassium Fulvate | Crystal, flake, powder |
| Foliar sprays | Fulvic Acid, Bio Fulvic Acid, Potassium Fulvate | Powder |
Key specifications
| Product | Humic / fulvic acid, min | Other | Water solubility / pH |
|---|---|---|---|
| Humic Acid | 50–60% humic acid | 65–85% organic matter | pH 3.0–7.0; dissolves in alkaline solution |
| Potassium Humate | 60–65% humic acid | 10% K₂O | 97–100% water-soluble |
| Super Potassium Humate | 65% humic acid | 10% K₂O | pH 9.0–10.0 |
| Sodium Humate | 50–65% humic acid | — | 85–100% water-soluble; pH 9.0–10.0 |
| Super Sodium Humate | 60% humic acid | — | 99% water-soluble, min; pH 9.0–10.0 |
| Fulvic Acid | 55% fulvic acid | 12% K₂O | 100% water-soluble |
| Bio Fulvic Acid | 50% fulvic acid (powder) | 10–12% K₂O | Powder / granule |
Humic acid, fulvic acid, K₂O and organic matter are minimum values (dry basis where stated); pH is a range. From the current SAINT TDS; the full specification is in each product’s TDS.
How they are applied
- Soil application, together with base fertilizer
- Blending into compound and NPK fertilizers
- Dissolving in drip-irrigation water (water-soluble grades only)
- Foliar spray (fulvic acid grades)
- Application rates depend on crop, soil and formulation; ask us for technical guidance and run a small trial first.
Common questions
Is humic acid water-soluble?
Humic acid itself dissolves in alkaline solution, not in water. Potassium and sodium humates are the water-soluble forms.
Which grades suit drip irrigation and foliar spray?
Water-soluble grades: Super Potassium Humate for drip irrigation and spraying, Fulvic Acid for irrigation and spray fertilizers, Bio Fulvic Acid for foliar spray, and Potassium Fulvate for foliar spray or drip irrigation.
Can humates be mixed with urea, DAP or MAP?
Potassium humate is often mixed with urea, DAP or MAP in compound fertilizers. Check compatibility in your own formula before production.
What documents come with an order?
Depending on the product and order, we can provide a Certificate of Analysis, Technical Data Sheet, Safety Data Sheet, batch identification and export documentation.
Before you order
- Check compatibility with the other fertilizers in your formula.
- For organic farming, check with your certifying body.
- Ask for the TDS and a sample for your own trials.
