Fertilizer 101

What The Numbers Mean

On a package of fertilizer you will find three or four numbers separated by hyphens.

The first numbers the percentage of nitrogen (N), second number phosphorus (P), third numbers potassium (K), and last number indicate sulfur (S).

Macronutrients vs Micronutrients

Those main nutrients are called “Macro-nutrients”, and a "complete" fertilizer must contain nitrogen, phosphorus and potassium.

In addition, there’re trace elements which also importance as well : iron, zinc, copper, calcium, manganese and magnesium which are necessary for plants to complete there life cycle so we call it “ Micro-nutrients”

What they do

Nitrogen

Nitrogen is required for the green and leafy vegetative growth of plants. All plants need nitrogen to make amino acids, protein and DNA. Nitrogen fertilizer is often synthesized using the Haber-Bosch process, which produces ammonia. Deficiency symptoms of nitrogen are an overall pale yellow color of leaves and dwarfed or stunted plants

Nitrogen is easily leached down through the soil below the roots and is not available to the plant so is the element most often lacking and needing replacement. In addition, too much nitrogen can delay flowering, fruiting and seed set.

Do you know that most of the nitrogen on Earth is in the atmosphere and approximately 80% of the molecules in Earth’s atmosphere are made of two nitrogen atoms bonded together (N2)

Phosphorus

Phosphorus promotes root growth, root branching, stem growth, flowering, fruiting, seed formation and maturation. Phosphorus is involved in photosynthesis, seed formation, and numerous other plant functions. Ammonia can be added to the super phosphoric acid to create liquid or dry materials containing both nitrogen (N) and (P), and the liquid 10-34-0 is the most common product. Deficiency symptoms are indicated by a red or purplish tinge to steams and foliage. Phosphorus is stable and non-mobile element in the soil so leaching is not a problem.

Potassium

Potassium enables the plant to withstand stress such as drought, cold, heat, and disease. It also stimulates flower color and promotes tuber formation and a strong root system. Deficiency symptoms are indicated when the leaves appear dry and scorched on the edges and have irregular yellowing.