Sulfur Fertilizers and Potential Moisture Absorption
When you think of sulfur fertilizers, there is always some concern around moisture absorption depending on fertilizer storage conditions. For this reason, it is important that farmers are aware of the potential for fertilizers to absorb moisture based on weather patterns.
Fertilizers with a higher critical relative humidity (CRH) – the value at which fertilizers begin to absorb moisture from the air – can be stored and handled in humid conditions. Fertilizers with a lower CRH will carry a higher potential for moisture absorption if stored in humid conditions.
If the relative humidity of air surrounding fertilizer is higher than the critical value, then the fertilizer will begin to absorb moisture. Moisture absorption leads to fertilizer caking, which negatively affects physical handling of the product during loading and application. The amount of time a fertilizer spends under high humidity can lead to greater potential for moisture accumulation.
How does Smart Nutrition™ MAP+MST® stack up?
Compared to ammonium sulfate (AMS), Smart Nutrition MAP+MST has shown to have a higher critical relative humidity and less moisture absorption when stored under high humid conditions. Less moisture accumulation has led to a lower caking percentage of the stored fertilizer.
After one year of storage at a location in Minnesota, Smart Nutrition MAP+MST showed little crust on the fertilizer pile surface, with the pile breaking up as you run your hands through it.
This indicates that Smart Nutrition MAP+MST can be an ideal fertilizer source for humid conditions where other sulfur-containing fertilizers may not be an option.