Can biologicals fill the soybean nitrogen gap? The jury's still out

Berner Tobin here at the Midwest Ag Conference. I'm catching up with Greg Stewart, Syngenta's biological field specialist. Sir, how you doing? Hey, Bern, nice to see you. Hey. I want to talk about a conversation that you had here with Horst Bonner today about closing the end gap on soybeans and I guess the role of endophytes, biostimulants, two things that you're working on. Tell us about that conversation and I guess some of the research you're doing and you know, nitrogen is a part of that and how it all comes together. Yeah, well, it's really an intriguing question in terms of you've got a nitrogen gap in soybeans, which essentially means that when you get to high yield levels, it looks like there isn't enough nitrogen coming from nitrogen fixation or from the soil to meet the requirement of the high yielding beans. It starts at 60 bushels per acre and then grows as yields continue to climb. But even if we had 10 to 50 pounds of extra N, it would cover off a fair bit of that high yield gap. So if you put nitrogen fertiliser down, you have an influence on the nodulation and the amount of N that you're getting out of the nodulation side of it. So it would appear that that was the perfect opportunity for an endophyte, a bacteria that could colonise the tissue of the soybean and pull N out of the atmosphere into the canopy, and it wouldn't have any impact on the nitrogen that the plant was getting from the soil or from the nitrogen fixation itself. So it was an eloquent plan fit. Right. But in our now 14 trials where we looked at Invita, which is the Syngenta N fixing bacteria, we had a really hard time showing that the bacteria actually contributed in and therefore did not normally contribute to much yield in that picture. Right. So I don't think we give up on the idea. It's too eloquent to think that, yeah, if we could get an endophyte that could bring nitrogen in and not disrupt or not have to put nitrogen fertiliser on the soil and all the challenges that comes with that, that would be. That would be a really nice fit. But so far our end fixing endophyte has not played in that space in terms of Giving us N or yield. But I don't think we would exclude. The idea that there isn't another version, another species, another approach to that end, fixing endophyte that might still work. Now, in this trial, you also had biostimulants, so talk about what you saw there with the products you used. Sure. Well, again, one of the nice things about these sets of trials is that we looked at the endophytes and we looked at nitrogen fertiliser. A pretty reasonable thing to cheque if you're going to fill the end gap. Right. But then we thought, well, let's look at biostimulants as well. And so in our data, in the first year, it actually looked at biostimulants competed fairly well. That is, if you looked at return on investment, a yield on, which is a sort of a reproductive biostimulant that Syngenta has a single application of yield on in that R2 window, actually was the one treatment that had some return on investment. Right. We Fast forward to 2025 data, which was a drier, more stressful year. You would have thought that maybe we could have gotten more out of the bio stimulant. It actually gave us less in 2025. So over the whole picture, what do you walk away saying? Well, you walk away saying that of the possibilities of endophytes adding nitrogen fertiliser or applying a bio stimulant, a biostimulant, was as reasonable approach to improving soybean yields as any of the possibilities. And on occasion, made you a few bucks. I was going to say, on 70% of your trials, you saw a positive impact. A couple of bushels, 1.5. But, you know, there's something to build on that. Yeah, I think there's something to build on that. The idea that this is the first generation, at least, certainly from my perspective, but also from Syngenta's perspective, the idea of this is really our first generation of biostimulants. And to find a product that can fit in that window of stimulating yield improvement by perhaps improving the way starch flows from the leaf to the seed, that's not such a bad thing to chase. Right. We have had genetic improvements that have made significant improvements in yield without improving the amount of water that they take up or any of that, it's a physiological response in the plant. So we're still encouraged by the idea that a biostimulant, a biostimulant can do some things within the physiology of the plant that could boost yields, even if it's modest, where we're at now. Yeah. Final point, trials for next year. Where do you go next? Where do we go next? Well, we continue to look at this idea of where biostimulants fit and a little bit down the road of checking, you know, we take the sort of, what I should say maybe is the North American approach to applying products to crops where it's one time, one shot, control the problem, move on. I think we still are in that process of understanding that biostimulants may not work that way. They might need multiple applications at a more careful timing in order to stimulate the approach within the plant. We're not trying to control a disease or control a weed that can be a one and a done. This is more of a bouquet of products to stimulate the plant and that may need more attention to how many times you apply it and when specifically do you apply it to get that stimulation that you're looking for? Well, good stuff, Greg. Always appreciate you making some time for real agriculture. Talk to you next summer. Great burn.