Late-Season Nitrogen Applications Increase Soybean Yield and Seed Protein Concentration

Anuj Chiluwal, Erin R. Haramoto, David Hildebrand, Seth Naeve, Hanna Poffenbarger, Larry C. Purcell, Montserrat Salmeron

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Low seed and meal protein concentration in modern high-yielding soybean [Glycine max L. (Merr.)] cultivars is a major concern but there is limited information on effective cultural practices to address this issue. In the objective of dealing with this problem, this study conducted field experiments in 2019 and 2020 to evaluate the response of seed and meal protein concentrations to the interactive effects of late-season inputs [control, a liquid Bradyrhizobium japonicum inoculation at R3, and 202 kg ha−1 nitrogen (N) fertilizer applied after R5], previous cover crop (fallow or cereal cover crop with residue removed), and short- and full-season maturity group cultivars at three U.S. locations (Fayetteville, Arkansas; Lexington, Kentucky; and St. Paul, Minnesota). The results showed that cover crops had a negative effect on yield in two out of six site-years and decreased seed protein concentration by 8.2 mg g−1 on average in Minnesota. Inoculant applications at R3 did not affect seed protein concentration or yield. The applications of N fertilizer after R5 increased seed protein concentration by 6 to 15 mg g−1, and increased yield in Arkansas by 13% and in Minnesota by 11% relative to the unfertilized control. This study showed that late-season N applications can be an effective cultural practice to increase soybean meal protein concentration in modern high-yielding cultivars above the minimum threshold required by the industry. New research is necessary to investigate sustainable management practices that increase N availability to soybeans late in the season.

Original languageEnglish
Article number715940
JournalFrontiers in Plant Science
StatePublished - Oct 6 2021

Bibliographical note

Funding Information:
The authors gratefully acknowledge the funding from United Soybean Board (USB Project# 1920-152-0127 and Project# 2020-152-0110) and from the University of Kentucky (Hatch funds) to conduct this research.

Publisher Copyright:
© Copyright © 2021 Chiluwal, Haramoto, Hildebrand, Naeve, Poffenbarger, Purcell and Salmeron.


  • bradyrhizobia soil inoculation
  • cereal rye
  • cover crop
  • oat
  • soybean meal
  • winter wheat

ASJC Scopus subject areas

  • Plant Science


Dive into the research topics of 'Late-Season Nitrogen Applications Increase Soybean Yield and Seed Protein Concentration'. Together they form a unique fingerprint.

Cite this