2020
A Survey of Delaware Soybean Variety Tissue
Contributor/Checkoff:
Category:
Sustainable Production
Keywords:
GeneticsGenomicsSeed quality
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Jarrod Miller, University of Delaware
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:

Soybean varieties, fertilizer delivery and micronutrient products continue to develop and improve. However, soybean nutrient recommendations rely on data that is decades old. As soybean production inputs and systems improve, do nutrient recommendations need to be updated? Soybean tissue surveys for nutrient concentration identify what research is needed to answer that question. This work uncovers opportunities to improve nutrient guidelines for farmers, allowing them to fine-tune soybean nutrient delivery to maximize yield and return on investment. In the short-term, these survey results let farmers know what nutrients to be paying attention to in their own tissue sampling.

Key Benefactors:
farmers, agronomists, Extension agents

Information And Results
Project Deliverables

Final Project Results

Updated March 25, 2021:

View uploaded report PDF file

Strong relationships between maturity group and nutrient uptake were not observed in this study, but potential herbicide damage, drought, and other environmental conditions may have contaminated the study. Instead the strongest relationships in Delaware for soybean yield remain to be soil type and access to adequate moisture. Soil nutrient concentrations varied by site, which is not unusual considering variation in management and natural soil variability.

However, there were some interesting relationships for nutrient uptake and sufficiency ranges. The only nutrient that did not meet the sufficiency range was leaf concentrations of Ca. When compared to yield, higher Ca levels had a weak, but significantly negative relationship with yield. Whether this means Ca sufficiency levels are high, or nutrient imbalances needed corrected is not known. A more confusing observation is that Middletown had the lowest Mg, Cu, and Fe in the soil, but the highest in the whole plant tissue. Middletown also had the lowest P concentration, but a higher leaf P, but lowest whole plant P concentration.

Some of the strongest correlations to yield included Mg, S, and Cu, which all increased in the plant with higher yield. These three nutrients were also correlated to each other by plant tissue concentrations. Higher potassium in leaf samples was actually related to lower yield though, which may indicate some kind of stress or competitive uptake with Mg or Ca.

Sodium tissue levels were similar to the 2019 statewide survey, which was also the only plant nutrient which correlated to yield. In 2019 we assumed this to be a corollary to irrigation, with higher plant levels related to irrigation water salt concentrations. In the 2020 variety trial study, Na had a negative correlation to yield as well as Mg, S, and Cu. As a monovalent cation, it would also be expected that Na would have a negative relationship with K uptake, but this was not the case. With tissue levels similar to 2019, it can be assumed that Na uptake was either in competition with other nutrients, or the result of some kind of environmental stressor. As this study was not controlling for any nutrient or variable, that cannot be known.

This study leads us to conclude that Mg uptake, and its relationship to soil and nutrient characteristics, needs further study for soybeans in Delaware. Whether it is important for increasing yields or is a corollary to other abiotic controls on soybean growth warrants further investigation.

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.