Sulfur is a chemical element of symbol S, atomic number 16 and atomic mass 32 u. At room temperature, the sulfur is in the solid state.
SULPHUR SOURCES
Sulfur estimated to be the ninth most abundant element in the earth. OS in the form of sulfides, sulfates, and elemental sulfur is approximately 0.06 to 0.10% of the earth's crust. Inactive or free OS is mostly sedimentary volcanic deposits. OS is the soil in inorganic and organic forms. In the soil solution S is present as sulfate ion.
SULPHUR IN AGRICULTURE
The sulfur requirements for crops are lower than Nitrogen and Potassium, but similar or superior to those of phosphorus. Nevertheless, the sulfur is often wrongly relegated to the background in the management of crop fertilization. The sulfur content in plants ranging from 1 to 5 g kg -1 of dry matter, considering levels between 1 and 3 g kg -1 as appropriate for normal growth of plants.
PHYSIOLOGICAL FUNCTION
- An important element for the production of amino acids, proteins and chlorophyll;
- Component of some hormones and vitamins of the plant;
- Improves root growth and promotes vigor and robustness the same;
- Participates as a binder in a number of metallo-enzymes and proteins.
SULPHUR ABSORPTION WAYS
OS is absorbed by plants primarily in inorganic form as SO 4 -2, it is then reduced and incorporated into organic compounds. In recycling S, this returns to the soil in inorganic form, where mineralized by microorganisms before it is used by higher plants.
SULPHUR DEFICIENCY SYMPTOMS IN PLANTS
The symptoms are:
- Plants showing leaf blade uniformly yellow or chlorotic, especially in young leaves;
- Smaller plant development;
- Short internodes;
- Reduction in flowering;
- Less nodulation in legumes.