2020
Impact of Sulfur Fertilization on Soybean Seed Protein and Amino Acids and Yield
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
(none assigned)
Lead Principal Investigator:
Frank Yin, University of Tennessee-Institute of Agriculture
Co-Principal Investigators:
Project Code:
2020-152-0112
Contributing Organization (Checkoff):
Brief Project Summary:

Unique Keywords:
#seed composition
Information And Results
Project Deliverables

Final Project Results

Updated January 24, 2021:
Final Report
Sulfur (S) is a key component of amino acids, proteins, and peptides. Thus, S deficiency can significantly reduce soybean seed protein and amino acids and seed yield. Since there was little information available about S 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 S fertilizer application rates and timings on soils with low to medium initial S fertility levels. The two-year results of this project showed that applying S 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 significant increases in leaf S concentration during early season on both low S and medium S soils and in late season on low S soils. Significant increases in leaf chlorophyll, plant height, plant biomass, and numerical increases in seed yield were frequently observed on both low S and medium S soils. Averaged over the low and medium S soils, the effects of S applications on seed S, cysteine, and methionine concentrations were significant. All S applied treatments had higher seed S concentration than the zero S control. Numerical increases in seed protein were frequently observed with S application. In this study, the greatest increase in protein was from 40.55% under zero S application to 41.61% with application of 30 lb S/acre at planting. The largest increase in cysteine was from 0.625% under zero S to 0.665% with application of 30 lb S/acre. The maximum increase in methionine was from 0.567% under zero S to 0.595% with fertigation of 20 lb S/acre at V4. The concentrations of seed S and methionine were significantly related with S application rate under a quadratic model. The regression of cysteine concentration with S rate was very close to being significant (P=0.0597). In conclusion, applying S fertilizer via soil application at 10 to 40 lbs/acre at planting or fertigation at 20 lbs/acre in early or late season is beneficial for increasing seed S concentration, and thus enhancing cysteine and methionine concentrations in soybean seeds on low S and medium S soils. Sulfur applications may be beneficial for seed protein and seed yield under certain production and environmental conditions.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.