Role of sulfur mineralization and fertilizer source in corn and soybean production systems

Sulfur (S) is an important nutrient for plant growth and crop yield. In the northern U.S. Corn Belt, a decrease in atmospheric S deposition increase grain harvest have increased frequency of deficiency corn (Zea mays L.) soybean [Glycine max (L.) Merr.]. Nevertheless, remains difficult to predict owing complex interactions between production plant-available sulfate-S from soil organic matter (SOM) mineralization losses leaching. Our objective was measure yield response four fertilizers (ammonium sulfate, elemental S, gypsum, polyhalite) 1st year following fertilizer application 2nd (residual) Iowa. Across 4 site-years, none products 12 site-years application, based while had no effect. 6 second residual polyhalite, gypsum 1 site-year ammonium sulfate Laboratory incubations confirmed that there slower compared with sulfate-based fertilizers, potentially explaining lack effect application. contrast our expectations, weak, but positive relationship SOM concentration. Overall, kinetics solubility appear affect magnitude timing fertilizer.