SULFUR  (S) 32.06 Atomic Weight

(Secondary Nutrient)

Sulfur (Sulphur) is estimated to be the ninth most abundant element in the universe.  It constitutes .03% of the earth’s crust.  After Oxygen and Silicon, it is the most abundant constituent of minerals.  Sulfur is essential to all life as a component of fats, organic fluids, and bones.  It is non-toxic in its elemental form as well as its sulfate compound.

Uptake of Sulfur in plants is in the form of sulfate ions (SO4---).  Sulfur may also be absorbed from the air through the leaves in areas where the atmosphere has been enriched with Sulfur compounds from industrial or volcanic sources.

Sulfur is a constituent of two amino acids (methionine and cysteine) and is therefore essential for protein synthesis.  It is also essential for nodule formation on legume roots, and is present in oil compounds responsible for plant odor.  It helps in chlorophyll formation.