CROP NOTES for March 30, 2010
Iowa State University Extension Information for Northeast Iowa
By Brian Lang, ISU Extension Agronomist
911 S. Mill Street, Decorah, IA 52101
Great Time to Setup a Sulfur Fertilizer Strip-Trial
Research trials on sulfur fertilizer for corn in northeast Iowa show positive results about 100% of the time on sands, 70% of the time on silt loam soils, 60% of the time on loam soils, and only 14% of the time on clay loam soils (all of these fields were without any recent manure history). If you are on a silt loam (Fayette, Downs) or loam soil, how do you know if you will benefit?
The sulfur soil test is no help in determining sulfur recommendations. Plant analysis works good for alfalfa, but not corn. We recommend a simple sulfur fertilizer strip trial to help you see if sulfur fertilizer will pay on your fields. It’s easy. Get a spreader with Calcium sulfate (gypsum) set to spread about 100 lbs of product per acre. That will give you about 16 lbs of sulfur per acre. Spread on your fields of interest leaving a large gap between spreader passes. E.g. make a 60-foot spreader pass, skip over 120 feet, make a spreader pass, skip over 120 feet, make a spreader pass. Now you have 6 strips, 3 with sulfur and 3 without. Do this on as many fields that you are interested in.
Calcium Products Tip: Many dealers carry SuperCal SO4 pelletized gypsum!