In season Sulfur fertilizer application at footslope of Field

This study took place in Minnehaha County, on the foot slope of a farm. On May 15, 2020, soybeans were planted in 30-inch rows at 160,000 seeds per acre. The two treatments in this experiment were nitrogen with sulfur fertilizer and nitrogen without sulfur fertilizer. For nitrogen with sulfur treatment, 30 lb/ac and 15 lb/ac nitrogen fertilizers were mixed and applied at the R3 growth stage, respectively, while nitrogen fertilizer was applied alone at 30 lb/ac at the same time for nitrogen without sulfur treatment. Polymer coated urea and ammonium sulfate is used as nitrogen and sulfur fertilizer sources, respectively. There were four replications of each fertilizer treatment. For this experiment, the plot was 10 feet wide by 30 feet deep. The combined application of nitrogen and sulfur treatment was subtracted from nitrogen treatment to calculate the effect of sulfur on soybean yield.

From the experiment, sulfur increased yields by 0.1 bu/ac (Table 1), but the difference was not statistically significant. Dry conditions for several weeks after application may have adversely impacted the treatments, as water is needed to incorporate these fertilizers into the soil for root uptake. To determine the effectiveness of the treatment, further experiments and more replications should be conducted at multiple locations.