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Soil Nutrients – NPK and others

The Big Three

The three primary macronutrients are nitrogen (N), phosphorus (P), and potassium (K).

N is Nitrogen – Leafy growth uses nitrogen.  Nitrogen greens up grass and makes soft sappy growth.  Leaf plants especially benefit from Nitrogen.  These include lettuce, spinach, and other greens.

P is for Phosphate – To stimulate root growth, use a phosphate fertilizer.  A phosphate fertilier particularly helps potatoes, carrots and other root crops.  Phosphorus is ususally in good supply in organically enriched soils.

K is for Potash – To stimulate the growth of fruits and flowers, use potash.  Potash also hardens up growth for protection against disease and winter cold.

Most vegetables use these three major nutrients in a ratio of roughly 3-2-1.    This  ratio is more “balanced” in meeting plants’ needs than one that is 1-1-1.

Other Nutrients

  • the three secondary macro nutrients are calcium (Ca), sulfur (S), magnesium (Mg).

  • the micro nutrients (trace minerals) are boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo) and selenium (Se).

One of the best ways to ensure a wide variety of nutrients into your soil is to use compost in your garden. Not only will compost contain a wide variety of macro and micro nutrients, it helps soil structure and porosity, improves aeration, and includes beneficial microorganisms.