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Welcome to University of Minnesota Extension's Nutrient Management Podcast. Each month we bring you the latest research in nutrient management for crops and how you can incorporate the latest tips and best management practices to your farm.
Welcome back to University of Minnesota Extension's Nutrient Management Podcast. I'm your host, McDivitt, Communications Specialist here at U of M Extension. Today on the podcast, we're talking about manure management. We have two members of Extension's Nutrient Management team. Can you each give us a quick introduction?
Melissa Wilson:Hi, I'm Melissa Wilson. I'm the Manure Management Specialist.
Chryseis Modderman:And I'm Chryseis Modderman, the manure management extension educator.
Paul McDivitt:All right, Chryseis, can you tell us a little bit about some of the events and educational programming you're working on?
Chryseis Modderman:Yeah, so there's a great online program that's coming up that I'm really excited about. It's the online manure composting workshop. So this is gonna be a joint effort between the University of Minnesota and NDSU Extensions. We had originally planned to hold this workshop in person, but then with all the events happening now, we ended up moving it online. So we've kind of had to get a bit creative to put it online.
Chryseis Modderman:So Melissa, myself, and our NDSU collaborators have been working really hard on videos to get those up and making composting videos. So how this composting workshop is going to work is it's going to be kind of in two parts. So the first part is the videos with composting content will be posted online on August 4. And so all registrants will get a link to that and you can work through those at your own pace, watch the videos at your own pace. There'll be, you know, content on application of compost, how to compost, the basics of that.
Chryseis Modderman:And something really cool that we have is we went and visited three compost producers and looked at their operation, took videos, interviewed them, talked to them, that sort of thing to get kind of a real world view of composting and starting out with composting. So those videos will be up. And a week later on August 11, we're going to hold a live discussion. That'll be over Zoom. It'll be one to three p. M.
Chryseis Modderman:And that will be with those three compost producers again. They'll be present on that call. So you can pick their brains. You can shoot them a bunch of questions.
Chryseis Modderman:So I think that'll be really interesting. That'll be really cool. So, I mean, if you've ever thought about composting manure, if you've ever thought about trying it, this is a great opportunity. Registration is free. It's kind of self paced, so you can go through the videos at your own pace.
Chryseis Modderman:And then it's kind of set up for all experience levels. You don't really need to come in with any compost experience in the past or if you have a little experience, that's great too. You'll have some great questions to ask then. And then the other cool thing that's coming up are the commercial animal waste technician workshops. So those recertification workshops this last year, our last workshop, which was supposed to be held in Owatonna in March, I think, that got canceled.
Chryseis Modderman:So we are working on putting a replacement for that line. We don't have a concrete timeline or when that's going to be out yet, but it will certainly be before anyone's certification runs out or expires at the end of the year. So that's something to be looking out for too for anyone that needs to recertify for their commercial waste technician certification.
Melissa Wilson:And I just want to point out, Melissa, here, that you can also test if the online option wouldn't work for you. You can go to one of the retesting centers and test so that you don't have to take the online training. That is an alternative option.
Paul McDivitt:Chryseis, where can growers find out about these events online?
Chryseis Modderman:So you can find more information on the manure composting workshop at z.umn.edu/manurecompostingworkshops. And you can find out about the CAWT recertification workshops at z.umn.edu/cawt2020.
Paul McDivitt:Great. So jumping into the research side, Melissa, can you give us an update and kind of some background on your liquid swine manure side dressing project?
Melissa Wilson:Sure. So we started side dressing liquid manure probably, what is it, two years ago now? We actually stole the idea from some researchers out in Ohio. They have been side dressing liquid swine manure for five, six, seven years now. And we figured why don't we try it here in Minnesota?
Melissa Wilson:As of the first things I learned about when I came here is that it's becoming more erratic in the fall and spring with the weather, so farmers and applicators have really been having a hard time getting all the manure applied. So one of the opportunities is to think about what about during the growing season? So for the past two years we've been using a dragline system in on farm research to try to figure out if we could utilize that kind of system for application because dreg line systems are fairly popular in Minnesota. And the first year worked out really well. We compared liquid swine manure to anhydrous ammonia and UAN applied at about the same nitrogen rates.
Melissa Wilson:And it looked they were all really similar in yields. The moisture content of the grain was a little bit higher for the swine manure so that was kind of an interesting thing that we found. But otherwise, everything looked really good. So the second year it didn't turn out as well. We had a lot of challenges.
Melissa Wilson:It was still really wet in the particular field that we were doing this in, so we had some issues with the big soil clumps kind of overturning and going over the rows. And then we also had a technical error where we didn't apply the rates we were aiming for, so we didn't apply as much nitrogen as we thought with the swine manure. It ended up being about 50 pounds of nitrogen less than we expected, obviously you can expect lower yields in that case. So, you know, we think with some more practice that that's a promising option for people who'd be willing to consider it. We, you know, don't expect everyone to just turn to side dressing their swine manure, but it is certainly another tool in the toolbox.
Melissa Wilson:So this year we actually just got more funding to continue our research which is really exciting. And we're working again on farm but we're using a tanker system this time. We think the tanker system will give a little more flexibility with timing. So we're actually doing a timing study with the tanker. We're going in at V1 which is when the first main leaf is out, the first leaf collar is present, at V3 when the third leaf collar is present, and V7.
Melissa Wilson:Now V7 is a lot later than we would ever go with a dragline system. I wouldn't recommend going past V4, maybe even V3 to be safe. So it should be a really interesting comparison to see how this works out this year with these three different timings. And we are comparing that to anhydrous being side dressed around the V3 stage because that's kind of the farmer's traditional practice. So we'll see what yields look like.
Melissa Wilson:We're going look at soil nitrate and ammonium throughout the growing season and then at the end of the season we'll look at grain moisture. And the other big thing we're measuring is compaction. We do think compaction will be greater with the tanker system because, you know, obviously it's a lot of weight being pulled behind the tractor with the tanker system.
Paul McDivitt:Great, and, what about your AFREC funded manure NNP credit study?
Melissa Wilson:Yeah, that one has been going on for a couple years now. It's a little bit of a longer term study. The goal was to apply manure. We have two different locations. We have the Southwestern Research and Outreach Center in Lamberton, Minnesota, and then the Southern Research and Outreach Center in Waseca, Minnesota.
Melissa Wilson:The goal was to get on slightly different climates. You know, it tends to be drier in Lamberton, although I swear the last two years it's been wetter there than usual. Mean wetter in both locations but particularly wet in the Lamberton area. And to get a little bit of different soil types. And we wanted to apply six different types of manure.
Melissa Wilson:So we have beef bedded pack, we have swine finishing manure, raw dairy manure, and then we also got some liquid separated dairy manure because there's more and more dairies that are starting to use liquid solid separation. We also have a composted chicken layer manure and turkey litter. And the goal was to apply all of these using our current guidelines on what the nitrogen availability might look like, to apply 140 pounds of nitrogen per acre and this was all applied in the spring. And then we compared it we had fertilizer plots that ranged anywhere from no nitrogen fertilizer up to a full rate of nitrogen fertilizer. That way we could compare what the nitrogen uptake in the corn was for the manures versus what it looked like for the fertilizers which is kind of more of a known quantity to get a good estimate of what the fertilizer equivalence of the manure was in this particular year at these two sites.
Melissa Wilson:And then we'll be watching those sites for three to four years to see what kind of credits we'll get the second year from the manure, the third year, and maybe the fourth year. Although we'll see, this is our third year for those sites, We'll see what the yields look like this year. There wasn't very much nitrogen available the second year from the manures, so we're thinking the third year might be it. So we started those in 2018, then we started a second set of sites in 2019 as well. So we'll have a total of four sites where we're looking at first year available, second year available, third year available credits.
Melissa Wilson:So we have data back for 2018. We have yields for 2019 but we haven't got some of our nitrogen uptake figured out yet because we're kicked out of the lab for a few months here. But interestingly, for pretty much every manure source at both sites, we were not getting as much nitrogen released as we expected. And that can be probably attributed to the fact that 2018 was a fairly wet year. So there's circumstances which means those saturated conditions may not have allowed as much mineralization of that nitrogen as we would have expected.
Melissa Wilson:The three that were pretty decent though were the swine finishing manure, the chicken layer, and the turkey litter. Those were close to what we had expected. I would think they were within the variability of the range that we see of nitrogen mineralization. But the two that we'd kind of need to work on maybe, we had that bedded beef pack that did not release nearly as much nitrogen as we expected. We were looking for about 60% and we only got, I think it was eight to 15%.
Melissa Wilson:We think some of that had to do with the bedding. It was a bedded beef pack. One year it was kind of like a hay, grass bedding, and the other year it was corn stalks. But both years, we think we saw some tie up both in nitrogen because of that bedding. And then dairy as well had lower release than we expected whether it was raw or the liquid separated.
Melissa Wilson:One thing that we saw with the dairy was that at Lamberton, the raw and the separated behaved very much the same. But at Waseca, they actually behaved differently. The dairy liquid separated manure released more nitrogen than the raw dairy. So it was kind of a fun interesting thing. We don't know if it was weather related or if it's just the slightly different soil types.
Melissa Wilson:But all this is preliminary data. Once we get the second set of first year data, we'll have kind of a better knowledge base to look at these and see where we want to go with future research.
Paul McDivitt:So is there anything you two think farmers should keep in mind about manure management heading into the fall?
Chryseis Modderman:Yeah, so obviously we don't have a crystal ball on the weather and what the weather is going to do. But if it's been like the last couple years where the fall has been really wet and it's been challenging to get into the fields to apply manure, it's really good to have a backup plan for that. So the first thing you need to do with that is to assess your storage. How much storage do you have? How much do you need to get through the winter?
Chryseis Modderman:And what is the amount of manure that you need to get applied to get you through the winter until spring application. Because of course we want to avoid winter applications especially during the snow melt season which is, you know, towards the end of winter when storages might be getting extra full. So when you have to apply manure, when you had to wait for wet conditions and maybe the ground is getting a little frozen, you need to choose your fields carefully. You want to choose the driest, flattest field possible. And remember that when the ground is frozen, most of the setbacks go up to 300 feet.
Chryseis Modderman:And if you're applying on wet saturated soil, we kind of recommend that to that 300 feet setback. You can also use this neat tool from the MDA. They have the Runoff Risk Advisory Forecast that kind of gives you a forecast of how likely runoff conditions are in the next few days up to a week. You can sign up for alerts through email or through text. I get a text most mornings saying, 'Hey, your area's in a high runoff risk right now.
Chryseis Modderman:Maybe don't apply manure.' So to find that, there's a Z link. It's just RRAF. There is also, you can find it pretty easily just by searching Minnesota Runoff Risk Advisory Forecast. And then on top of all of that, you want to work closely with your county feedlot officer or your local MPCA official if your storage is about to overflow or if you're running out of storage space or if you just need help with your application conditions. If you're not sure what to do, it's best to involve them and keep them in the loop.
Chryseis Modderman:And then always have a plan for spills. Have the duty officer's number on call. Have a safety plan, and an emergency response plan for when things go wrong.
Melissa Wilson:Yeah, want to point out too, especially with the safety plan, be considering what to do if there is some sort of gas problem. There's a lot of different gases that can be toxic when they're associated with manure and some of them tend to be heavier than air so they will kind of sit close to the ground. And it's really important to be careful going into confined spaces. Always have someone in visual sight of you and if you see someone maybe pass out and you suspect gases, don't go in after them. That's probably one of the worst things you can do.
Melissa Wilson:Call your local emergency officials who can come with gas masks and hopefully handle this situation pretty rapidly. So manure gases are always a safety consideration when you're thinking about agitating this fall.
Chryseis Modderman:Yeah, and when dealing with manure gases like hydrogen sulfide or whatever, it's not just in confined systems where it's a concern. High gas buildup can happen in open pits, too. People don't often think about that. They think it's open to the air and so I can just agitate and get as close as I want and the gases won't affect me. But even in open systems, the gas levels can get quite high.
Melissa Wilson:Oh, one other thing I wanted to point out was that if you're planning on applying early, maybe after wheat or some canning crops or something like that, I know unfortunately there was a lot of hail damage, so if people were wanting to apply manure to those fields, definitely consider a cover crop this fall. With as warm as it's been, as long as it continues to stay warm, you might get a pretty good growth on that cover crop which will hopefully hold back some of those nutrients and retain them until the spring.
Chryseis Modderman:And then if we happen to have a great fall where conditions are fantastic, you know, I'm always the doom and gloom if weather is terrible but it could be fantastic too, who knows? You know, try to wait until the soil is down to 50 degrees or lower to apply your manure so that you don't lose a lot of your nitrogen to nitrification.
Melissa Wilson:Yeah, we've also seen, just was looking back through some of our old articles and one that came up recently was the nitrification inhibitors. Some of the research that's been done in Minnesota have shown that they can potentially work, at least for swine manure, that's what the research was done with. For applications in October or, you know, a few weeks before the soil temperatures might get down to that 50 degrees, so they might kind of give you a little bit of a longer window. But the research where they applied in September, which was a long time before the soil temperatures got down, the inhibitor kind of ran out so it didn't actually help. So that is one thing to consider.
Melissa Wilson:If you're going just a few weeks before that 50 degrees, an inhibitor might help but not necessarily the case if you're applying in September, it might not get you to that cold period.
Paul McDivitt:All right, that about does it for the podcast this week. We'd like to thank the Agricultural Fertilizer Research and Education Council, AFREC, for supporting this podcast. Thanks for listening.