Potassium humate

Potassium humate (CAS 68514-28-3), derived from leonardite or lignite through alkaline extraction, is the potassium salt form of humic acid used commercially as a soil conditioner, micronutrient chelator, and water treatment agent.

Where is Potassium humate used?

• Agriculture: improves nutrient availability and soil structure
• Crop nutrition: chelates iron, zinc, and manganese
• Keeps micronutrients in plant-available form and reduces fertilizer lock-up in high-pH soils
• Applied as a standalone soil drench, blended into NPK liquid fertilizers, or incorporated into slow-release granules
• Water treatment: coagulation aid and flocculant that removes suspended solids and organic matter from effluent streams
• Feed and soil amendment manufacturing: buffering agent that stabilizes pH in liquid concentrate products
• Can be applied to the soil or sprayed on the foliage.
• Developed for fertigation of field crops and for soil injection.

Formulation notes

• For base fertilizer application, applied at 5-10 kg per hectare, preferably mixed with nitrogen and phosphorus fertilizers.
• When blended with nitrogen fertilizer, used at 5% of the total blend, i.e. 5 kg per 100 kg of urea.
• Compatible with other fertilizers except phosphate fertilizers; in that case a separate tank is needed or the fertilizers must be applied at different times.
• Hard water rich in calcium and magnesium can cause precipitation and clog irrigation lines.

Typical specification

• Alkaline pH of about 9–10.
• Humic acid content on a dry basis is minimum 65% for flake, powder and granule forms.
• For flake, powder and granule forms, particle size is 2-4 mm; for powder it is 80-100 mesh.
• Moisture content is maximum 15% for solid forms.

Regulatory status

• Heavy metals (As, Cd, Pb, Hg) must be confirmed against the limits of Regulation (EU) 2019/1009 before booking for the EU.
• Potassium humate and humic acid are generally classified under HS heading 3101, but may shift to 3105 or 3824 depending on product form and destination.
• Organic certification depends on the certifier and the specific product; buyers should request the organic certificate listing the exact SKU, certificate number and validity.

Frequently asked questions about Potassium humate

Why is potassium humate preferred over sodium humate as a fertilizer?

In practice, potassium humate is preferred as a fertilizer over sodium humate because it provides beneficial K2O and avoids sodium loading in soil, which can damage soil structure upon repeated use.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.