SUL4R-PLUS granular calcium sulfate is available immediately to the plant.
SUL4R-PLUS fertilizer is fully usable upon application. If you use elemental sulfur, you could wait months for it to be effective because it must be converted to the sulfate form by microbes in the soil. These microbes are most active with warmer temperatures, oxidized soil and adequate, but not saturated, soil conditions.
In order for elemental sulfur to work most effectively it needs:
• Sulfur to be mixed with the soil to provide contact
• Well-aerated soil – microbes need oxygen
• The right amount of moisture – not too wet or too dry
• Warm soils (not typically found early in the planting season)
• Time – some say it may be up to 6 weeks to as long as a year before elemental sulfur is usable by the crop
Some sulfate forms pull in moisture from the air especially when mixed with other fertilizers—not SUL4R-PLUS® fertilizer.
The critical relative humidity (CRH) of a salt is defined as the relative humidity of the surrounding atmosphere (at a certain temperature) at which the material begins to absorb moisture from the atmosphere and below which it will not absorb atmospheric moisture.
When the humidity of the atmosphere is equal to, or greater than, the CRH of a sample of salt, the salt will take up water until it is dissolved to yield a saturated solution. All water-soluble salts and mixtures have characteristic critical humidities; it is a unique material property.
The CRH of most salts decreases when temperature increases. For instance, the CRH of ammonium nitrate decreases 22% with a temperature from 0°C to 40°C (32°F to 104°F). Mixtures of salts typically have a lower CRH than either of the constituents.
In the spring it is very common to have a CRH greater than 57% when sulfur is applied. Humidity levels are usually greater in the morning hours.
SUL4R-PLUS granular calcium sulfate is moderately water-soluble (~2.0-2.5g/L at 25°C) and, in contrast to most other salts, exhibits a retrograde solubility—becoming less soluble at higher temperatures. SUL4R-PLUS fertilizer is 17% sulfur and 21% calcium.
SUL4R-PLUS fertilizer…priced similar to elemental sulfur with the benefits of a sulfate.
“Finally, a sulfate source I can inventory to blend mixtures for all crops without adding additional nitrogen, picking up moisture from the air, or lowering the pH!” – John Ezinga, Michigan Ag Commodities, Middleton, MI