Summary of Sulfur Strip Trials Conducted in Central and Northeast Iowa

Report extract:

Last fall Sulfur (S) strip trials were conducted by John Sawyer, Professor; Daniel Barker, Assistant Scientist; ISU Extension Field Agronomists Brian Lang, George Cummins, and Mark Wuebker. The product was aplied by Heartland Co-op, Innovative Ag Solutions, and Five Star Co-op.  Calcium Products, Inc. provided the SuperCal SO4 gypsum used in the central Iowa trials with Heartland Co-op.

RESULTS

Six of the ten field sites had a corn yield increase from the S application (Table 1).  The other four sites had no yield difference with or without S application.  This is a 60% response rate to S application, which is similar to other recent small plot research conducted in north central to northeast Iowa on S response in corn.  For the six responding sites, the average yield increase from S application was 9 bu/acre, with a range of 5 to 13 bu/acre.  These yield increases are large enough to more than pay for a S application (for corn, suggested rates are 15 lb S/acre for fine-textured soils and 25 lb S/acre for coarse-textured soils).

This initial strip trial work indicates that S deficiency is occurring across a wide geographic area of iowa from central to northeast Iowa, and at a frequency that justifies continued research on S fertilization and deficiency identification across Iowa corn and soybean production.

Calcium Products would like to thank everyone involved, especially the farmer cooperators!