By Daniel Kaiser
One thing I hear a lot from people is that sulfate, the form of sulfur available to plants, does not hang around in the soil from one year to the next. In most soils, the rate at which sulfur leaches is much slower compared to nitrogen in the nitrate form (the exception being sandy soils which can quickly leach most nutrients). While it is true that sulfate has a negative charge and can be leached, the rate of leaching really depends on the soil.
What does current research say about how sulfate carries over in Minnesota soils?
Currently, I have multiple research projects funded by both the Agricultural Fertilizer Research and Education Council (AFREC) and the Minnesota Soybean Research and Promotion Council studying how sulfur carries over in our soils.
In my AFREC-funded long-term sulfur trial, we applied sulfur over a period of four years in continuous corn. In year five, we divided the plots where sulfur was applied into two areas: one where sulfur applications continued and one where we stopped applying sulfur. Annual sulfur rates were 5, 10, and 20 pounds of sulfur per acre, comparing sulfate to elemental forms of sulfur fertilizer.
Source : umn.edu