NPK fertilizer contains three essential nutrients needed for plant growth and overall plant health. These three essential nutrients include nitrogen (N), phosphorus (P), and potassium (K). What is NPK fertilizer good for? The nitrogen in NPK fertilizer is useful for helping plants to growth leaves. Phosphorus, by contrast, helps to produce healthy flowers, buds, roots, and fruits. Potassium is used by plants to help sustain overall plant health. What does NPK ratio mean? The NPK ratio refers to the three numbers that indicate the percentage of nitrogen, phosphorus, and potassium in an NPK fertilizer. A 20-20-20 fertilizer, for example, would have 20% nitrogen, 20% phosphorus, and 20% potassium. Al Sadek Group of Companies can provide you with different grades of NPK.