Fertilizer Info

IS&F Granular and Water Soluble Fertilizer Information

What do the Fertilizer Numbers Mean?

The numbers that you see on the fertilizer is the ratio of nutrients that the fertilizer is made up of. Example 29-9-10-2S. The first number represents N or the nitrogen in the blend. The second number represents P or the phosphorous in the blend. The third number represents the K or potassium in the blend. After these three numbers other numbers describe micro nutrients that make up the blend. These numbers are followed by their elemental sign. Examples: S is sulfur, B is boron and Fe is iron. 

For the example 29-9-10-2S. The numbers describe the ratio of 29 nitrogen, 9 phosphorous, 10 potassium and 2 sulfur.

What does each nutrient do?

Nitrogen: Nitrogen is a very important and needed for plant growth. It is found in healthy soils, and give plants the energy to grow, and produce fruit or vegetables. Nitrogen is considered the most important component for supporting plant growth and is essential for photosynthesis.

Phosphorous: Phosphorous is considered second to nitrogen as the most essential nutrient to ensure health and function. Without Phosphorus, photosynthesis could not occur. Phosphorus plays a key role in complex energy transformations that are necessary to all life. Phosphorous facilitates root growth, strengthens stalks and stems and improves flower formation and seed production.

Potassium: Potassium like the other macro nutrients is highly important in plant growth and health. Potassium is associated with the movement of water, nutrients and carbohydrates in plant tissue, as well as regulating the rate of photosynthesis. Potassium facilitates increases root and crown growth, improves drought resistance and improves disease resistance.

Sulfur: Sulfur is considered an essential mineral. Sulfur in plants helps form important enzymes and assists in the formation of plant proteins. It is needed in very low amounts, but deficiencies can cause serious plant health problems and loss of vitality.