Photo of the Month – Sulfur Coated Urea (SCU)

Sulfur Coated Urea (SCU)


The invention of Sulfur Coated Urea (SCU) in the 1970s provided the agricultural industry with a new way to slow release nitrogen and at the same time provide plants with much needed sulfur. Since its invention, SCU has been adopted for use worldwide. It has become even more important to agriculture in recent years as sulfur once obtained by crops from industrial air pollution is no longer available in our cleaner world.

ACT is proud of their history in the development of coated fertilizers. In fact, our founder, Ray Shirley, was the lead inventor of SCU at Tennessee Valley Authority! Since establishing ACT in 1981, Ray has built a group of professionals with expertise in fertilizer coatings. As a result, we understand the importance of attention to detail in the development of coatings that successfully extend or delay the release of nutrients.

Coating fertilizer for slow release is more than a science. It requires a combination of knowledge, skill, observation, innovation, and art. For a coating to be commercially viable, careful planning is required to minimize the cost of the coating and still provide the desired release profile.  This attention to detail includes:

  • Careful examination of physical properties of coating materials and substrate – viscosity, melting point, freezing point, water affinity, density, biodegradability, and much more
  • Proper selection of equipment used for coating
  • Quality and chemical composition of starting materials
  • Estimation of release properties of the coated product during early development
  • Agronomic and performance testing of the fertilizer product
  • Economic feasibility of coating

The coated fertilizer industry is entering a new era as environmental restrictions are beginning to shape and transform the industry. Recent changes in EU fertilizer regulations have triggered revived interest in SCU and other coated fertilizer products. Efficient use of fertilizer nutrients is ever important but doing so in an environmentally friendly manner is changing the approach of fertilizer companies.


Recent Articles