Sulphur – The Fourth Major Plant Nutrient

Nitrogen (N), phosphorus (P) and potassium (K) are critical components of a well-fertilized crop. But to achieve yields and more nutritious foods, crops need sulphur (S). This website is an introduction to sulphur and its important role in agriculture.

Role of Sulphur in Plant Growth and Development

Sulphur is one of the 17 essential plant nutrients. It is essential for the growth and development of all crops, without exception. Like any essential nutrient, sulphur also has some key functions in plants:

  • Formation of chlorophyll that permits photosynthesis through which plants produce starch, sugars, oils, fats, vitamins and other compounds.
  • Protein production. Sulphur is a constituent of three S-containing amino acids (cysteine, cystine and methionine), which are the building blocks of protein. About 90% of plant S is present in these amino acids.
  • Synthesis of oils. This is why adequate sulphur is so crucial for oilseeds.
  • Activation of enzymes, which aid in biochemical reactions in the plant.
  • Increases crop yields and improves produce quality, both of which determine the market price a farmer would get for his produce.
  • With reference to crop quality, S improves protein and oil percentage in seeds, cereal quality for milling and baking, marketability of dry coconut kernel (copra), quality of tobacco, nutritive value of forages, etc.
  • It is associated with special metabolisms in plant and the structural characteristics of protoplasm.

TSI's Promotion of Sulphur Fertilizer Use

The Sulphur Institute has recently increased programming promoting the use and importance of sulphur fertilizers. TSI staff has conducted interviews and developed print materials supporting this message. Click here to read more.

Sulphur Deficiency Sources and Symptoms

Sulphur deficiency symptoms resemble nitrogen deficiency: the leaves become pale-yellow or light green. Unlike nitrogen, sulphur-deficiency symptoms appear first on the younger leaves, and persist even after nitrogen application. Click here to read more.

Sulphur Fertilizer and Crop Yield

While soil tests for sulphur deficiency indicate the likelihood that a crop grown on that soil will benefit from or respond to sulphur application, the real proof is when on such soils, sulphur application actually increases crop yield. Click here to read more.

Sulphur Fertilizer Types

Most sulphur-containing fertilizer materials generally can be divided into four groups: 1) fertilizers containing sulphate, 2) fertilizers containing elemental sulphur, 3) fertilizers containing a combination of sulphate and elemental sulphur, and 4) liquid sulphur fertilizers. Click here to read more.

Additional resources

Information and Advocacy Programs

Click here to learn more about the other activities of TSI's Information and Advocacy working group