Updated December 9, 2019:
Sulfur (S) is a key component of amino acids, proteins, and peptides. Thus, sulfur deficiency can significantly reduce soybean seed protein and amino acids and seed yield. Since there was little information available about sulfur fertilization effect on soybean seed quality, the objective of this project was to determine the responses of soybean seed protein, amino acids, and yield to sulfur fertilizer application rates and timings on soils with low to medium initial sulfur fertility levels. The first year results of this project showed that applying sulfur fertilizer via soil application at 10 to 40 lbs S/acre at planting or fertigation at 20 lbs S/acre in early or late season resulted in frequent numerical increases although statistically insignificant in plant growth, plant sulfur nutrition, and seed yield on both low and medium sulfur soils, which suggests that sulfur fertilizer application may increase the contents of seed protein and amino acids and seed yield of soybean under the production conditions in Tennessee and the Mid-South region.