Sulfur is a macro-nutrient that is needed in large quantities for all crops including soybean. In fact, S is needed as a co-factor for proper nodulation and fixation by Bradyrhizobium japonicum for soybean. Sulfur has also been noted to improve efficiency of nutrients like N and Mn. The improvement in nutrient use efficiency is particularly appealing when applications of phosphorus and potassium are made in the spring or even at planting. In a preliminary trial in 2019, we documented yield improvements of phosphorus and sulfur co-application (7.8 bu/ac). Potassium applications at planting of soybean can cause yield loss (- 5 bu/ac in 2019 trial); whereas, the addition of sulfur with potassium offset this yield suppression. Baseline sulfur application have created synergistic opportunities with in-season foliar protection. In another preliminary trial in 2019, we documented no yield response to foliar applications of fungicide, insecticide, and fungicide + insecticide when applied alone. However when these applications were combined with a PRE-emergence application of sulfur, yields increased 4 to 7.5 bu/ac depending on the combination. Our research aims to determine the best options (e.g., fertilizer combinations to be broadcast applied prior to planting, foliar sprays during the growing season) to manage nutrients (i.e., P, K, S) for soybean and determine opportunities for synergies in management to optimize yield and quality (i.e., protein). We propose three studies to accomplish this mission with the goal of multiple year evaluations across several locations: Nutrient Use Efficiency via Sulfur x NPK, Sulfur x Foliar Protection, and Field-Scale S x Foliar Protection.