NPK NPK 191919 Water Soluble Fertilizer is a type of fertilizer that contains high amounts of nitrogen (19%), phosphorus (19%), and potassium (19%). It is a balanced fertilizer that is often used to provide crops with essential nutrients for growth and development. The nitrogen component of NPK 19-19-19 helps promote leafy growth, the phosphorus component supports root and flower development, while the potassium component enhances plant health and disease resistance. NPK 19-19-19 is commonly used in agriculture, horticulture, and gardening to improve soil fertility and increase crop yields.