Humic Acid Potassium Foliar/Drip Fertilizer 1.organic humic acid from leonardite 2.water soluble fully 3.foliar/drip apply Humic Acid Potassium Foliar/Drip Fertilizer HumiSun is extracted from the natural high grade leonardite,formulated potassium salt of humic acid. It contains both nutrient potassium and humic acid and fulvic acid.Especially for the fulvic acid, its lower molecule makes ...