The Top 3 Macronutrients Found in Soil: The NPK Ratio and CEC

NPK Ratio

NPK ratio refers to the three nutrients: nitrogen (N), phosphorus (P), and potassium (K). NPK labels on fertilizer bags show a ratio to inform the user how much of each nutrient exists in the bag. The NPK ratio 10-10-10 stands for the weight in pounds of each nutrient. A 60-pound 10-10-10 bag would be ten pounds each of nitrogen, phosphorus, and potassium, with the remaining thirty pounds being filler.

Main functions of nitrogen and potassium are that they are elements of nucleic acids & proteins, which are important components of plant tissue. Phosphorus has importance in the regulation of processes in the plant, such as enzyme activities and osmosis.

Nitrogen

Nitrogen is related to photosynthesis and chlorophyll and oversees plant growth. A lack of nitrogen can lead to slow growth, short rhizomes, and yellowish stunted leaves. Nitrogen is vital to the building of protein and enzymes. It is the leading electrolyte found in soil, boosting electrical conductivity. This corresponds to nutrient availability.

The nitrogen element absorbs into Ammonium (NH4+) and Nitrate (NO3-) ions. Unlike other macronutrients, nitrogen is not directly available from the earth’s crust or atmosphere.

Phosphorus

Phosphorus is a vital part of DNA and RNA, which helps in genetic transfer and seed yield. It is also essential for ATP (Adenosine Triphosphate), the energy unit of plants. Phosphorus helps in photosynthesis, energy storage, cell division, and root growth.

Potassium (Potash)

Potassium is crucial for water retention, making plants more resistant to diseases. It regulates stomata function, enzyme activation, and overall physiological processes. The letter K in the periodic table comes from the German word "Kalium."

Cation Exchange Capacity (CEC)