Biostimulants
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Jack Wilcox: Welcome back to the University of Minnesota Extensions Nutrient Management podcast. I'm your host, Jack Wilcox communications generalist here at U of M Extension. In this episode we're talking about biostimulants. We have three members of Extension's nutrient management team here with us today. Can you each give us a quick introduction?
Dan Kaiser: My name's Daniel Kaiser. I'm a nutrient management specialist on the St. Paul Campus. One area that I do a lot is on product testing and I'm work with the NCERA 103 group, which is the regional group that has put together the compendium of non-traditional products for those that might be interested in, if you're looking at what's been tested in the past or specific products, there's a website that you can go to that has some more up-to-date research on some of the products that have been tested. So it's been one of the things that I've been interested in because I get a lot of questions in my Extension role on a lot of these products.
Carl Rosen: Hi, I'm Carl Rosen and I'm a Extension specialist and my area of expertise is nutrient management and I've also worked with NCERA 103, the alternative or non-traditional products and also I encourage you to take a look at the website and look at some of the research that's been done on some of these alternative products.
Lindsay Pease: And I'm Lindsey Pease and I'm an assistant professor in the Department of Soil Water and Climate up at the Northwest Research and Outreach Center and I have a few experiments out right now that are looking at the impact of biologicals on some soil fertility.
Jack Wilcox: Thank you so much. Let's get into the first question. What's new on the topic of biostimulants?
Dan Kaiser: Well, Jack, it's interesting when you look at the market right now, particularly the interest in biological products, I mean, they've been around for a long time and certainly if you look at some of the seed treatments that have been going on the seed already for what some of your corn treatments, they may include some biological products and we're looking at it, it's right now, I think the key expansion is in some of these, what we call free living nitrogen fixers. So in the area of sustainability, a lot of people have a lot of interest really in looking at ways to reduce the amount of nitrogen that they need to apply with fertilizer and try to come up with some other, redeem more sustainable practice. So that's been the big thing. There's a few key ones proven from Pivot Bio is probably the biggest one if you look from a marketing standpoint right now, that's a free living end fixer.
One of the other products, Utrisha, and there's one other one that always escapes my mind, that's... We get a lot of questions on right now that are really big in the marketplace and with the fertilizer prices the way they are, I mean certainly growers have been looking for a way to really look at reducing the amount they need to apply. So they're looking for that general option that might be a cheaper option although you look at all of these products, they still aren't free so if you look at the price you're paying for them, you could be paying essentially about two thirds of the price you would be for fertilizer for one of these products. So you really need to make sure they work and that's been kind of the questions that we've had, which we'll talk about research here I think in a little bit is from a lot of growers is do they work?
And you see a lot of reports from, particularly in the popular press on growers that have been using some of these things. And it's been one of the things I've really been on my end, more of a cautionary tale really to read into a lot of what's going on because certainly the marketing arm there is really pushing a lot of these positive effects. So you need to have a general idea on where these things are going to work best because they're not a definite thing to use. So that's one of the things that I guess concerns me right now with it, and we've seen this in the past with a lot of products. They tend to come and go where they'll get a lot of interest and if growers aren't seeing the consistent benefit from them, they tend to start to fade over time. So we'll kind of see what happens here because the sustainability piece is huge and I know growers are really looking at more ways to the sustainability piece as well as a lot of industry too, really to start looking at reducing some of the nitrogen they need.
Carl Rosen: Yeah, I think Dan, the one product you were thinking of, but couldn't remember the name is Enveda and that's the one that was originally isolated from sugar cane and it does fix nitrogen. It's an endophyte, so it works within the plant, but it's different than Rhizobium where there's a very mutual association with legumes. This endophyte is not as specific and can also infect corn and perhaps other crops as well but it is supposed to fix nitrogen similar to some of the other products on the market.
Dan Kaiser: Yeah and I think Nutrisha may be the one that's foliar applied. I haven't had as much experience with some of these products. The thing about a lot of these products that are out there right now is that they work outside of the plant so when you start looking at situations like Rhizobium that are the nodules in legume crops, that's more of a symbiotic relationship where the plant supplies the food for the bacteria, then the bacteria in turn supply nitrogen directly to the plant. So with a lot of these products that are out there, they're going to be free living and ideally what's going to happen is some exits from the roots that the plants are going to release are going to supply food to that bacteria where they in turn would supply some nitrogen.
So that's one of the things that are the big question right now with this because if you look at a lot of our soils, I mean I think certainly if you're looking at a lot of these products in a situation where we didn't have a lot of biological activity, I think it'd be more clear cut where there might be a benefit from these, especially if you could get something that would colonize to do what it says it's supposed to do. The main thing though, when I look at these is it's interesting because one question that, and one of our last, I don't think it was the podcast, it was one in a particular article we had released in one of our croppy news blogs, somebody had made the comment that with these biologicals, it didn't get to a point at which we don't need to apply any fertilizer and I don't think that's the case.
The research really isn't there right now with that, that we can completely get rid of all of our fertilizer applications. I mean they might supply a small amount of what the crop needs, but there's really nothing out there that's going to completely unlock essentially what the nutrients in the soil make everything completely available where we won't we'll be able to apply or raise a full crop without fertilizer application.
Carl Rosen: Yeah and we're mainly talking about non-legumes of course. So yeah, these free living nitrogen fixers and even the endophytes that are nitrogen fixers cannot supply all the nitrogen that's needed by the crop no matter how good they might be. So yeah, you're always going to have to try to apply some or need to apply some nitrogen. And one of the problems is that when you apply nitrogen, at least for most of the microbes, adding that nitrogen will suppress that nitrogen fixing ability and that's the one thing about the proven product that's been genetically modified to be able to withstand higher amounts of fertilizer nitrogen so it doesn't shut down the nitrogen fixation process. At least that is the idea behind that one.
Dan Kaiser: And so with a lot of these too, I mean it's amazing to me how many are actually out there. We can't possibly test them all and that's one of the things if you are looking for information, I mean if you know what's actually, or what strains of bacteria are in these things that you could go and do some search for some older research to look at. Some of this was, again, a lot of this isn't new.
I mean obviously though there's a lot of strains that these bacteria out there, and that was one of the points that was brought up recently when we were talking about some of these things at the crop pest management short course in December of 2022, is that one person brought that up. I mean in terms of what strains were being tested in a bunch of interactions and the thing is, this isn't a simple issue when you start looking at these.
I mean it seems like more and more we're isolating strains throwing them a jug and selling them to growers but the survivability, I think, is the main question on a lot of this and I don't really know what's going to really what's going to happen when those organisms hit the soil? Are they going to survive or not and do what they say they're supposed to do?
Carl Rosen: Yeah, there's a lot of competition out there when you think about just a gram of soil, how many microbes are in one gram, and when you spray a couple gallons over a whole acre, the ability of that strain or strains that might be applied to compete with what is existing in the soil can be quite difficult and so you might get maybe an effect very early on, but then those strains are overcome by the native bacteria or native fungi with other microbes that are in the soil.
Lindsay Pease: Yeah, and I think to both of those points, Dan, and I heard you mention this too, and I actually had somebody else mention it to me later on. I mean, the number of new products that are being registered at Minnesota Department of Agriculture in particular is just going up and up so it's really hard to keep on top of all of the different products that are being released and so I think that's where can I try to understand these mechanisms of how they're supposed to work is maybe one good way of trying to filter through whether or not these products might work or if a similar mode of action's been successful in the past.
Jack Wilcox: What new research can you talk about related to biostimulants?
Lindsay Pease: Well, I think one of the projects, I actually have a couple product projects going on right now where we are testing some of these products. One of them is in conjunction with Dr. Paulo Pagliari who's out of the Southwest Research and Outreach Center. So he's my counterpart in the southwest corner of Minnesota. We are looking at a specific strain of Azospirillum to be able to do that nitrogen fixing... Fixed nitrogen from the atmosphere and into the soil for the non-legume crops. We are testing it in wheat, but I will say that we've got mixed results the last couple of years. We really aren't seeing a real consistent response to that and I think some of that could be the survivability question that Carl just mentioned. Actually we sent some microbial samples to another one of the faculty members in our department, Dr. Sotoshi Ishii and he looked for that particular species in midsummer and couldn't find it in the samples that we sent.
So I think this summer we had some survivability issues, but we also had a drought and so we were really short on rain both in Lamberton and in Crookston so I think that's one of the things that makes it kind of hard to weigh in on whether these products are working as intended. Where we did see a response, we did see that the bacteria could fix about 15% more nitrogen to the plant, but really the most consistent place we saw a response was where there was no nitrate added, which is obviously not a very realistic scenario. We do have another product that is part of a trial that we're looking at. It's another one of those foliar sprays. The data's not fully analyzed on that either. The foliar spray is meant to stimulate the microbial community, but just looking at test weight on soybeans, we didn't see any response this past summer of that product either.
Carl Rosen: And so a lot of these products, when they're being developed, they isolate bacteria maybe from some Rhizosphere of high yielding crops, corn maybe, or wheat and then they take those microbes and culture them and they get very pure cultures. And then you can inoculate the crop that's of interest, say corn but a lot of times the initial results are based on greenhouse studies where you have ideal conditions, you have the moisture that you need to encourage growth, and there you can see potentially some results. But then when you take it out to the field, as Lindsay just said, that can be a whole different question. Depends on the environment, the rainfall, the weather conditions at the time. There's so many interactions that can occur.
Dan Kaiser: Yeah, and it's interesting to me, you look at, I mean I've been here in Minnesota since 2008, and when I came in first the big question right then in that point was solubilizing phosphorus. So they were looking at JumpStart, which is active ingredients, penicillin bilaiae, which is a fungus that's supposed to colonize around the roots and acidify the area around the roots, try to release phosphorus ideally in a high pH environment. You look at where that product is now, I don't hear a lot about it. I think it's probably still around. I mean penicillin bilaiae, if you go into the compendium and non-traditional products, you'll find research from that probably from 30 years ago where they were looking at that. So the concept, I mean it's interesting if you look at a lot of the concepts on these products, I mean there is some scientific merit in it.
It's just whether or not it translates well to a larger area. Like Carl said, you test something in the lab, you might be able to find that circumstance where it works very well but in the field, when you're dealing with billions of microbes in such a small area that's in the soil, it's what you're applying that little amount you have overtake the natural biology that's within the soil. So again, I started, we tested that. We were testing Avail at that point in time, which isn't a biological product. I tested SoilBuilder AF and which is also accomplished LM, which is a manure T, which is supposed to stimulate microbial activity, increased nutrient uptake and now I've kind of moved towards, and we were doing some testing with some of these nitrogen enhancers. And the big thing I can say on these things is they aren't consistent.
I think the SoilBuilder AF, when we looked at testing, I had 11 or 12 sites, one at which we saw a response to and then with this, the Pivot Bio products, it's been one out of six, which would say, well, 17% of the time I saw a response but the thing challenge about testing a lot of these products is you could catch lightning in a bottle and you hit just that exact one site where you see a response and you know, you could test it a hundred more times and never see anything occur again. So that's the thing that I think you look at these things, there's some promise in them, but looking at taking that to the field, it isn't always definitive and that's kind of talking about a lot of these things. I talked to a lot of consultants that have done a lot of testing too, and they see a lot of the same things.
And I think the challenge for these products, while I think there'd be some value if you could get them to consistently work, it's getting them to consistently work is the issue, and just packaging something and throwing it in a bottle, really in selling it, I think there's a lot of issues there with that because you look at it's just more than just putting this stuff on because obviously the question is did you put on enough because maybe you put on enough in a setting you could get it to work, but is that economical where a farmer's going to pay for that? I mean, that's always the question and then I go back to, it gets into the soil, will it have the desired impact? Because that's been the main thing is I'd like to see consistency and that's kind of the thing that I really you have to ask growers is how much consistency do you want to see in a product to make it worth your while to look at it?
What percentage of the time does it need to work? And then what evidence do you need that that product works to make you make that decision that it's something to try. I mean, that's the big thing is they've seen all sorts of things right now claimed on these products then how they work when in the end, most growers are really interested in yield and that's kind of the challenge. I mean, you can kind of prove, or maybe it takes up some nitrogen early in the growing season, but if it doesn't give you that benefit where I can reduce my nitrogen rate and get the same yield, then does it really matter? So that's the challenge with a lot of these things is its what's your definition of works? What do you need to know to prove it works, to really to give you that evidence that this should be something you should try.
Carl Rosen: The other thing is the application and how you apply it. Sometimes they recommend applying it with say, a starter fertilizer, and you wonder whether a microbe can actually withstand the concentration of fertilizer that might be there. So some companies have tested that, they claim that the microbes can, but I think you need to be a little bit careful about mixing it with concentrated fertilizer.
Dan Kaiser: And who has starter? I mean that's the problem, Carl. You deal with a lot with sands, we know that starter's a big risk in sands and as growers have gotten bigger, I mean that's the problem with in-furrow. I mean I do research on it, but you still see it in say Western Minnesota because of the high pH soils, I mean growers like a little bit of phosphorus right ahead of the corn, which is I think a good option but in other areas of state, there isn't that option. So that's the challenge, really is can you apply it the way it needs to be applied? And I know some of these companies are working, especially the Pivot Bio product to come on a seed placement, which would expand out the acreage where it could be applied and which is really what they need to be looking at doing because we look a lot at in-furrow, but that option just then isn't always there.
Carl Rosen: Yeah, right and they also talk about mixing it with certain pH in the water if it's too high or too low. So if you can do a seed placement, that's good, but you also have to remember that there's fungicides applied with seed placement and you wonder how that might affect some of the microbes as well.
Jack Wilcox: If a farmer wants to test biostimulants, how would you go about it?
Carl Rosen: Well, I think you want to make sure that you have the right comparisons. You don't want to be testing a product one year and then comparing it with what you did the previous year or the next year so you want to make sure that you test it the same year with the control, control meeting your normal practice without the product and ideally you would like to have replication in your field where you apply it so you're not just looking at say, one portion of the field relative to another portion of the field, but you actually have strips in there where you can say, this has it and the other area does not have the product. So you can have side by side comparisons but replicated at least three times. I think that's the best way to be sure that you're going to see a response. And then when you do that, you look at the yields, you look at say the nitrogen content in those areas where you have it, and then compare it with the areas that you don't have.
Dan Kaiser: So for us, I mean it's easy with our small plot research because I can take eight nitrogen rates, I can put the product to do with and without the product, and we can make that comparison. It's not something a grower can do. The other thing that's nice for me is I can screw up because I mean I'm not a big of a risk for loss that a grower would be should you buy something or should you under apply your nitrogen and reduce yields? So that's ideal. We're in a situation, some of the work we were doing with Proven, we had eight nitrogen rates, I had five to six replications, and that's some pretty powerful data when you can get that back and look at that. Now, what I really suggest to growers is exactly what Carl said is you've got to have a comparison with and without at the same nitrogen rate.
Now I've seen some protocols pushed for testing these products where you take the standard rate compared to the standard rate, maybe minus 30 or 40 pounds with the product and then make that comparison and I think for most growers, you get the same yield, they consider that a win. Well, the problem is a lot of that, if you start looking at from a company perspective, it works really well for them because if the grower's already over-applying by 30 to 40 pounds, maybe they could have just reduced the rate anyway. So it's really what I've been stressing to growers when you're testing these things, if you're going to do that reduced rate with the product, make sure you have that reduced rate without, because now you've got three comparisons. I've got, okay, can I reduce my rate? Then I have that reduced rate with the product.
If that yields higher than a reduced rate without, then I have some certainty essentially that product's actually doing anything because that's one of the things a lot of these products claim that they increase nitrogen uptake, and again, most growers are going to look at the yield side and on my standpoint, I mean it's nice to really know that the way that that product's supposed to work, that it's effectively working. So if it's increasing yield at a lower end rate and over that lower end rate alone, I mean then I have a little more certainty that's effectively working. So I'd at least do three strips and I'd replicate at least four times. If you're replicating, I'd also not just alternate yes, no, yes, no, yes no, because if you've got a general yield gradient in your field where it goes higher and lower from one side to the next, you're going to be biasing it one way or the other.
The nice thing with RTK right now, the way most growers are set up, they have a lot of flexibility and if you do have an in-furrow set up, one of the things I've been looking at is like a Dosatron, which I think some growers have, especially if they're looking at headline applications, that you can actually blend or blend those products in the line and turn that on and off so you could go in, apply some strips without, and then come back and then fill with if you wish to do so and put the product on the rest of the field. But you can skip where you're not just alternating passes, just you do comparisons and kind of randomize where those are at and it gives you more power. The big thing I know a lot from where it gets to be a little bit daunting is on the statistical analysis side and there are ways you can get around doing that.
It means certainly if you've got a large number of growers that if you want to get some analysis, I'm more than willing to work with you on the analysis side. I mean you can even code things where I don't even know what the treatments are and I can send you the data back just to give you a general handle because that's really the key because you just can't use yield averages because one of the things if you look at any of our data from non-responsive data, you can't expect non-responsive data that all your treatments are going to have the same yield across the board. What non-responsive data looks like is there's just the yield that's sometimes higher, sometimes lower. Generally the average across is going to be about the same, but it isn't that you're going to see each treatment have the same yield across the board.
And I think a lot of growers will look at that. If you get a two bushel difference in there, they'll think that that's significant and a lot of times if you look at your variability in your reps, that's really what our statistics looks like and gives us overall certainty that we're making the right decision. So I mean it's complicated. I know a lot of growers don't want to look at it, but I think it's an important step and that's one of the things if you can get together, if you've got a consultant group that wants to work and get a number of growers together, really the power in a lot of this is the more sites you get, the better off you're going to be because then you can start looking at the probability that the product works and then you might be able to tease out maybe situations where it works better than others.
Because that's the thing is that you're just not going to find these things work a hundred percent of the time. And I don't care what any company says that their product works 90, 95% of the time you look at it, you got to kind of dig into a little bit on what they claim in terms of how that product's working because if it's not, again, decreasing the amount of nitrogen you need to get the same amount of yield, to me that doesn't mean that I don't care if it gives you a little bit of uptake early in the growing season or some end of the season measurements are different versus other. It's really that yield that pays the bills and that's the data you need.
Carl Rosen: Yeah, just kind second what Dan said. That was a good explanation and you will, even if you set up strips in your field and don't do anything, you'll see yield differences with those strips. So that's why you need to do replication and you need to do with and without. And also, as Dan said, that's really important if you're going to reduce the amount of end with the biostimulant, you also need to reduce the amount of end without the biostimulant to make sure that you can compare apples to apples. And so it's really important to have the right comparisons in there. So a minimum of three treatments, as Dan said, is important. So you're conventional, a reduced end and then a reduced end with your stimulant if that's the way you're going.
Lindsay Pease: Yeah, and I think also trying to keep as many other factors the same as you can so you can really test just the effect of that product and that may go without saying, but you know, you don't want to have it on part of the field that maybe had corn in the last year and then part of the field that might have soybean in the previous year. You want to keep things consistent, even sometimes different soil types running through the field can cause a difference and these are all things that, when we're designing a trial at the university system, we're trying to keep as simple as possible, but I know it's also kind of hard to think of everything but if you think of as much as you can, that just kind of increases the chances that you'll be able to feel confident in your results and in your design.
Dan Kaiser: Well, one of the things that I think Carl brought up, but I think is key. I mean if these products are supposed to increase nutrient availability, you cannot over apply your nutrients. So with nitrogen, I mean if you're over applying your nitrogen, these things aren't going to give you a yield bump. I mean, that's not the way they're made. So if you're looking at something that's supposed to supply a portion of your inorganic nitrogen, you have to really look at your testing at a reduced rate. I mean, it has to be less than an optimal level to get a difference. Zero may not be the best because sometimes you know, you may not see a good result, but if you're doing it, just don't over apply it so what I'd look at is what we recommend for our MRTN and just try to stick at that or less.
If you're going to do a testing, no matter where your standard rate is, because more often than not, at least you'd be in, hopefully in a responsive range of that nitrogen response curve particularly for a nitrogen study, that's really important because as we get closer to that upper end, I mean you're not getting much of a yield increase per pound event applied anymore. So it really gets to be hard to test things so that's the thing, just if you're looking at it, you have to look at a suboptimal rate or some way that are new. The nutrient you're looking at is limiting, otherwise it really isn't worth your time to try to test these things.
Jack Wilcox: Any last words from the group?
Dan Kaiser: So I want to bring a plug up for this NCRA 103 group. We do have a new website. If you go it's N-C-E-R-A one zero three.org so that's the new website to get into the compendium of non-traditional products. So again, if you're looking at that, it's always good to know the active ingredient or what's in your product because a lot of times you can search for that active ingredient and find some research on it because what we've seen, particularly with some of these products is there tends to be a change over in the names. Every once in a while they tend to reinvent themselves with a new trade name, but the active ingredients are about the same so you can kind of look at it, just see what's in there and just see what, particularly with the active ingredients, if you know what that is, what research is out there.
So that's one thing that's resource that's out there that's kind of nice to have. I know also on these biologicals, Matt Ruark at Wisconsin had some handouts he developed talking about a few of these different bacteria so if you want to look at that too. I don't have the website in front of me, but I know he had some really good handouts produced that had some of that and some of that might be in the compendium, I'm not sure if that actually got put in so those are some resources if you really have some questions or just contact any one of us and we might be able to point you towards if you've got any questions on certain products so whether or not we know if there's any information locally.
Carl Rosen: Yeah, I guess the only thing I would say is don't rely on testimonials. Make sure that you make decisions on sound research, which is usually going to be conducted at the university and yeah, I think going from there, just be cautious because in most cases there's no silver bullet.
Lindsay Pease: Yeah, just keep in mind that your money is valuable and even though nitrate, as Dan mentioned before, even as nitrate costs are increasing, these products might not necessarily save you money in the long run, especially if they don't work as well as just the nitrogen rate itself.
Jack Wilcox: All right, that about does it for this episode of the Nutrient Management Podcast. We'd like to thank the Agricultural Fertilizer Research and Education Council or AFREC for supporting the podcast. Thanks for listening.
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