Potassium humate can be naturally found in lignite, from there it can be extracted.

write the chemical equation of prepearation potassium humate from humic acid

Humic acid is a large molecule derived from decaying organic matter, while potassium humate is a salt or derivative of humic acid where the potassium ion is attached to the humic acid molecule. Potassium humate is a more soluble form of humic acid that is often used as a soil conditioner and plant fertilizer due to its ability to improve nutrient uptake and soil structure.

James R. Gosz has written:

'Influence of road salting on the nutrient and heavy metal levels in stream water'

'An evaluation of New Mexico humate deposits for restoration of mine spoils' -- subject(s): Humates, Reclamation of land, Revegetation, Spoil banks