Soil Nutrients

These are normally divided into two groups named major nutrients and minor nutrients according to the quantities required by the plant

Nutrient	Chemical Symbol	Importance to Plants	Natural Source
Nitrogen	N	Synthesis of proteins, chlorophyll	Plant residues
Phosphorus	P	Synthesis of enzymes and the storage of energy.	Little natural reserves in the UK.
Potassium	K	Control of water by osmosis.	Much of UK soil, particularly where derived from igneous rocks, have a good reserve.
Calcium	Ca	Cell wall synthess, enzyme activity.	Vast reserves in calcareous (chalk) soil.
Magnesium	Mg	Chlorophyll synthesis	Reserves in magnesium limestone.
Sulphur	S	Synthesis of some amino acids (the building blocks for proteins).	Rocks and organic material.

There are also three other important macronutrients which may be considered separately

Nutrient	Chemical Symbol	Importance to Plants	Natural Source
Carbon	C	Synthesis of carbohydrates for strengthening and storage.	Carbon dioxide in the air.
Hydrogen	H	Synthesis of carbohydrates for strengthening and storage.	Water.
Oxygen	O	Synthesis of carbohydrates for strengthening and storage.	Air.

Nutrient	Chemical Symbol	Importance to Plants	Natural Source
Boron	Bo	Cell division
Manganese	Mn	Activation of some enzymes
Copper	Cu	Synthesis of some enzymes important in photosynthesis
Iron	Fe	Synthesis of chlorophyll, enzyme activity.
Molybdenum	Mo	Nitrate fixation
Zinc	Zn	Some enzymes
Cobalt	Co
Chlorine	Cl	Photosynthesis
Silicon	Si

There is also a group of nutrients which are not needed by plants but are essential to the horse:

Selenium, Iodine, Chromium, Flourine

Pasture Management
for
Horses