The Evaluation of Winter Wheat Response to Nutrient Sources of Sulfur and Application Timing

Enhanced efficiency fertilizers (EEFs) have gained considerable interest in recent years as human population trends demand greater productivity from cropping systems while minimizing human health and environmental concerns from nutrient loss. Previous research has shown EEFs to be beneficial in diverse cropping systems, but research into their use in winter wheat development has been limited. This study assessed the effects of Sulfur (S) sources derived from three EEF products in comparison to a commonly used commercial product (Ammonium Sulfate) and a control (no S) as well as the effect of application timing of S on the production of tillers and grain yield of winter wheat. Field trials were conducted over a 3-year period in Warsaw, VA and Westmoreland County, VA. During the early growing season of winter wheat, the tissue samples and aerial normalized difference vegetation index (NDVI) values of before and after the mid-winter application indicated that there was some response to application timing of S, but with the exception of the Warsaw 2021 second tissue sampling S percentage analysis, there was no significant response from the sources of S tested. As the growing season progressed, NDVI values measuring tiller density showed no significant difference, which later corresponded with the end of the growing season, as there was no grain yield response to source of S or application timing of S. Overall, the S additives from the EEFs tested did not consistently impact wheat tiller development or grain yield and are therefore cost prohibitive.