2023
Soybean Nitrogen fixation under Nitrogen and Sulfur fertilization
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Contributor/Checkoff:
South Dakota Soybean Research and Promotion Council
Category:
Sustainable Production
Keywords:
GeneticsGenomicsSeed quality
Parent Project:
Soybean Nitrogen fixation under Nitrogen and Sulfur fertilization
Lead Principal Investigator:
Jonathan Kleinjan, South Dakota State University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
South Dakota Soybean Research and Promotion Council
$20,234
Institution Funded:
South Dakota State University
$20,234
Brief Project Summary:
South Dakota is a participant in a national soybean research effort examining biological nitrogen fixation. Biological Nitrogen Fixation may be the most important economic and environmental process affecting soybean production in the United States, yet it is only partially characterized. We know little about the quantities of nitrogen fixed by the soybean crop or the fate of nitrogen in the environment. This project will help to better understand the soil, soybean management, and environmental factors affecting BNF along with the quantities of N fixed. This will contribute to knowledge for greater soybean yields, higher soybean quality and lower environmental impacts.
Key Beneficiaries:
#agronomists, #extension specialists, #farmers
Unique Keywords:
#nitrogen, #nitrogen fixation, #soil fertility, #sulfur
Information And Results
Project Summary

South Dakota has been invited to continue participating in a national soybean research effort initiated in 2021, examining biological N fixation with thirteen participating universities (Ignacio Ciampitti, Kansas State University; and Seth Naeve, University of Minnesota; Lead PIs). Biological Nitrogen Fixation may be the most important economic and environmental process affecting soybean production in the United States, yet it is only partially characterized. We know surprisingly little about the quantities of N fixed by US soybean crops or the fate of that N in the environment. A better understanding of the soil, soybean management, and environmental factors affecting BNF along with the quantities of N fixed will contribute to scientific knowledge leading to greater soybean yields, higher soybean quality, lower environmental impacts, and greater returns to US farmers.

Project Objectives

1) Estimate BNF and N budgets in soybean considering N and sulfur (S) fertilization rates.
2) Build a predictive model for BNF in the United States using environmental data.
3) Extend the results to soybean growers using local and national extension networks.

Project Deliverables

SDSU Extension articles, presentations, interviews. National fact sheets. Peer-reviewed publications.

Progress Of Work

Updated October 30, 2022:
Please see the attached document.

View uploaded report Word file

Updated January 30, 2023:
Please see the attached document

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Updated April 30, 2023:
Please see the attached document.

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Updated August 1, 2023:
Basically unchanged since the 3rd quarter report. Please see attachment.

View uploaded report Word file

Final Project Results

Updated August 1, 2023:
Data analysis on this nationwide study continues...I still have not been shared final 2 year results of this study. There is another journal article in the works from the KSU group and I plan to summarize the SD results in an extension article prior to the next planting season.

View uploaded report Word file

Due to the high uncertainty in treatment response and the contribution of N fixation, N fertilization is unlikely to increase yields in soybeans, leading to non-profitable recommendations. Sulfur deficiency, on the other hand, should be explored under site-specific conditions. Responses to S fertilization in South Dakota are unlikely due to high S concentrations in soil parent materials and relatively high soil organic matter.

Benefit To Soybean Farmers

A better understanding of when (or when not to) use N and S fertilizers in soybean production.

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.