By John Sawyer, Brian Lang, Daniel Barker
Producers applying sulfur may see benefits in alfalfa and corn fields
Sulfur Management for Iowa Crop Production, a new Iowa State University Extension and Outreach publication, provides a summary of research efforts and guidance on sulfur fertilization and application needs. The 2005-2013 data comes from on-farm, small-plot and field-length strip trials in fields across Iowa.
Farmers, crop advisers, agricultural businesses and suppliers know that sulfur has not historically been an issue with crop production in Iowa. However, this recent research shows improved crop yield when applying sulfur fertilizer in many areas of Iowa, specifically with alfalfa and corn production.
“Spring is a good time for sulfur application before corn and soybean planting, or before alfalfa re-growth,” said John Sawyer, professor of agronomy and extension soil fertility specialist with Iowa State University. “This allows time to get the applied sulfur into the root zone. Rapid sulfur availability is especially important if early season plant growth is exhibiting deficiency symptoms and sulfur is sidedress applied in corn or applied after an alfalfa cutting.”
“Research suggests a more consistent corn yield response to sulfur fertilizer; compared to soybean yield response,” said John Lundvall, soil fertility research team member at Iowa State University. “Given current commodity price pressure and close scrutiny of input costs for the 2015 crop, a farmer planting 2015 soybean into a field with documented sulfur deficiency might be best-served delaying sulfur fertilizer application until after the 2015 soybean harvest but prior to planting the 2016 corn crop.”
Publication authors are John Sawyer, professor of agronomy and extension soil fertility specialist with Iowa State University; Daniel Barker, assistant scientist of agronomy at Iowa State University; and Brian Lang, field agronomist with ISU Extension and Outreach.