Is nitrogen (N) important to soybean protein content? Yes, adequate N supply to the soybean plant is a determining factor of protein content in soybeans (1). Protein content can affect the price paid for soybeans as it is an important seed quality component and export determinant (2). In this week’s edition of Growing Possibilities, we ask: is N important to soybean protein content? We also explore strategies to ensure that soybeans get an adequate supply of N throughout their lifecycle.
Soybeans can access N in two ways: through atmospheric fixation with rhizobia that form a symbiosis with the soybean plant or, directly through the soil. About 50% of supplied N can come from atmospheric fixation from rhizobia (NO2) with the other half being supplied by N present in the soil (NO3). NO3 usually reaches an earlier maximum uptake than NO2 but both are necessary for high yields and protein content. NO3 plays a larger role in establishing plant biomass up to flowering while NO2 takes priority during the pod fill stage (3).
Because soybean plants require a strong supply of N compounds it is important to have a good fertility strategy that considers both N fertilizer as well as inoculation. “Applying your inoculant in-furrow or on-seed as part of your fertility program has been a strategy that our growers have seen success with,” says Jared Joyal XiteBio Regional Sales Manager Western Canada. “Early delivery of our advanced growth promoting technology (AGPT®) has been shown to produce strong nodulation in soybeans,” notes Joyal. Since soybeans rely on atmospheric nitrogen to help produce protein having good nodulation is an important factor in protein content in soybeans.
XiteBio® SoyRhizo® is a premium liquid inoculant powered by AGPT® that vigorously colonizes plant roots. “Inoculating your soybeans is like nodulation insurance,” says Joyal. “It is a simple thing that growers can do to ensure that they have good atmospheric nitrogen fixation in their beans which can lead to higher protein content.” XiteBio® SoyRhizo® is also designed to work in synergy with the native soil microflora instead of competing with them, meaning that this product also benefits the long-term health of the soil.
For those wishing to take their beans to the next level XiteBio® OptiPlus® dual inoculant for soybeans can provide both N-fixation as well as phosphorus (P)-solubilization. While P is not directly linked to protein production in soybeans a phosphorus deficiency can decrease the effectiveness of N-fixation by rhizobial inoculants (6). Adequate supply of P is therefore indirectly correlated to protein content in soybeans by boosting the effectiveness of N-fixing inoculants.
If you would like to learn more about this subject or receive information on XiteBio® SoyRhizo®, XiteBio® OptiPlus® or any of our products please contact one of our sales agronomists or give us a call at 1-855-XITEBIO. Until next time we wish you healthier plants and better yields.
- https://www.unitedsoybean.org/hopper/value-of-u-s-soybeans-the-proof-is-in-the-nutrients/
- https://manitobapulse.ca/2019/01/rethinking-soybean-protein-and-seed-quality-in-manitoba/
- https://www.sciencedirect.com/science/article/abs/pii/S0168945299002216
- https://mosoy.org/about-soybeans/environment/nitrogen/
- https://www.producer.com/news/high-protein-soybeans-could-benefit-western-canada/
- https://onlinelibrary.wiley.com/doi/10.1155/2023/3231623