Development of Brimstone90 began with the requirements of the crop. (For further information about crop requirements, see crop nutrition). Clearly, crops now require sulphur in quantities that cannot be supplied or satisfied by natural soil sulphur or soluble, leach-prone sulphate fertilisers.

In addition, the sulphur applied must have a release and availability profile that carries the crop right through the season without deficiency.

Naturally occurring soil bacteria, especially Thiobacillus spp., convert and solubilise elemental sulphur into the sulphate form at a speed which depends on the surface area available, which increases proportionately as the particle size gets smaller. This means that in order to provide both fast release sulphur for immediate use by the crop and slow release sulphur for use later in the season, a range of sulphur powder particle sizes are required.

These varying sized particles are combined with swelling, dispersing and suspending agents, such as bentonite, into a pastille which prevents dust and enables easy packing, transport, storage, and blending.

These agents ensure that the pastille breaks down on contact with soil moisture, releasing the particles and enabling the production of sulphate by soil bacteria.

With its novel formulation, Brimstone 90 claims the best swelling and distribution properties within the pastille sulphur market.