Ferticell Organic Pro K 0-0-20, 80 GallonPro K 0 0 20 Organic Liquid Potassium Fertilizer for Crop Production As an essential nutrient for plant growth, Potassium availability is critical for optimal plant growth. Many US soils with adequate organic matter can supply some, if not all potassium for crop production. Although when soil K supply is less than optimal, an organic liquid potassium fertilizer program is required, with no better alternative than Pro K 0 0 20. Understanding Pro K Pro