Sulfur (S) is a structural component of plant proteins and enzymes.  It is also part of some vitamins, and helps to support many function that can affect the final yield and quality of plants.

Role in Growth

Plants acquire sulfur from the growing medium as sulfate (SO4=). Sulfate is readily soluble and subject to loss by leaching. Plant metabolism reduces sulfate and sulfur dioxide to forms that can be used to build organic molecules. Sulfur is a vital part of all plant proteins, and certain plant hormones. It is also used in the formation of certain oils and volatile compounds found in the onion and garlic family.

Sulphur form an important part in the production of protein groups (especially amino acid cystine, cysteine and methionine) and alkaloid compounds. These three amino acids contain approximately 90% of the total sulphur found in the plant. Sulphur is also important for the formation of important metabolites such as coenzyme A, which is involved in the oxidation and synthesis of fatty and amino acids. Other substances which are important for the plant such as S-adenosylethionine, lipoic acid, sulfolipid and ferredoxin also contain S. These compounds are responsible for processes such as photosynthesis, nitrate and sulphate reduction and the synthesis of chlorophyll. Carbon dioxide assimilation and the nitrate/nitrogen reduction cycles are also influenced by the concentration of sulphur in the plant. The importance of sulphur cannot be underestimated!

In plants, sulfur plays a key role in aiding a variety of growth functions. These include:

  • Nutrient uptake and chlorophyll production
  • Seed development and root strength
  • Stress and pest resistance
  • Nitrogen utilization and carbohydrate formation
  • Vitamin synthesis