 Well, I'm Dave Fransen. I'm a soil specialist at North Dakota State University. I'm more of a soil specialist in soil fertility, and my colleague, Gabby Wick, is more a soil specialist in soil health. So I visited with Kelly a couple of weeks ago and asked him what he wanted me to address here at this virtual field day. And he suggested nutrient cycling and cover crops. So there are more and more people using cover crops as part of their cropping systems, and then this year, of course, there is prevent plant, and pretty soon, maybe a lot of it has already been done, maybe late July, but quite a bit of cover crops are going to go into prevent plant. One of the things that we've found over the years is that if you don't plant a cover crop in prevent plant and you do have a normal to what is sheer the next year, those are the first fields that are going to be prevent plant the next year. So I think in most years there's going to be more money in growing a crop than not growing a crop, and so if you have prevent plant and you have an opportunity to put a cover crop in, that's a good thing. So Abby and I have worked with a number of different cover crops over the past three or four years. Maricel Burdy had a big cover crop grant from the federal government, and we're part of it, and our job is to try to figure out what the nutrient cycling was. And I thought it was going to be slam dunk, that we just look at the carbon nitrogen ratio of what the residues of the cover crop was, the biomass. We'd figure out about how much nitrogen we thought would come out of it, and that would be the case. And we found that that's hardly ever the case. So we've worked mostly with cereal rye and forage radish. We had some turnip in the first year, but we're not crazy about turnip in a non-grazing type of a situation. We also had some camelina in there that sometimes overwintered and sometimes didn't, sometimes there's a prize in the spring. We also had a couple instances where we worked with growers that at one year I know we had a good stand of field peas within that rye and radish, and another year we had a good stand of fava beans within that cover crop of rye and radish. And I thought for sure that with a legume and a rotation that we get nitrogen coming off for the next crop. But when we looked at cover crop and no cover crop, there wasn't any contribution of the cover crop to the nitrogen nutrition of the following crop. And that just was a huge surprise. The carbon-nitrogen ratio of everything combined was less than 20 to one, which means normally that you would expect to have some nitrogen coming out of there. And it just wasn't. And we had years and we had over two tons of dry matter with 18 or a little bit less carbon-nitrogen ratio. You'd think there'd be substantial nitrogen coming out of there. And there wasn't any. So that was weird. But when I went around and started talking to my colleagues in other states, I found that they were having the same situation, especially when the cereal rye or an ode or barley or something with the radish was grown. That for some reason it just wasn't releasing it. It was certainly taken up a lot of nitrogen. In some of the studies that we did, the cover crops took up over 100 pounds of nitrogen per acre. But it just wasn't released in any of it the next year. We also don't think that it's leaching. We don't think that there's any denitrification going on. So we don't think there's any losses in the system at all. It's just not being released to the next corn crop or the next wheat crop or whatever crop that's going to be grown. So one of the things that we know from working with potassium for the last five, six years or so is that clay chemistry comes into play quite a bit with whether we have potassium released, especially in a dry stint during the summer or not. And it gets trapped in the inner layers of the clays. And one thing that people have forgot, not paid attention to, but ammonium, ammonium ion can also be trapped within that clay inner layer also, because it's about the same ionic radius as what a potassium ion is. And so I've been looking to see if that is where some of that nitrogen might be going. And during the dry summer, when we took our samples, we were finding way more non-exchangeable ammonia, we call it, in those soils than in the cover crops, the no-cover crop soil. So the cover crop, I suppose, at the very nano scale, it's shunting that ammonia that ammonia gets shunted into those clay layers during that decomposition process. Last year is very wet. And so in our potassium work, we found that if the soil is pretty wet during the growing season, then the clays really don't trap the potassium. They allow it to move around into the solution. And I think that's what we saw with the ammonium, too, because we saw no difference, hardly any difference, between the no-cover crop and cover crop. So we're continuing that this year to see if that's actually where it's going or not. But I think the bottom line is, is if you're growing a cover crop and it's a mix, maybe it has a legume in there, maybe it doesn't. And it probably almost always has a cereal grain in there, maybe or maybe not has radish in it. But if you have something that's not a straight legume, if you're just not planting all field peas or all phoba beans or all who knows what kind of clover, then you can't really count on that nitrogen being there because it tends to become trapped. If you did have a legume, just a straight legume, there it's expensive, the seed's expensive. So I don't know, the seed's probably going to be more than what the nitrogen's worth. That's why one of the reasons people do mix. But if you decide to do that and thumb your nose at the fertilizer companies, then I think you can take a portion of that the next year. But if you're using a mix, I don't think I would. If you think I'm nuts and you think that you have a great biomass buildup in your prevent plant that you planted the third week of July, it almost looks like a hay crop out there. And you can't imagine that you're not going to get 50 pounds of nitrogen off at the next year. Go ahead and put your base rate of nitrogen down with the 50 pounds subtracted off of it. But then in some corner, so you can watch it, put an extra 50 pounds. Whatever you decided to cut, just put a strip of additional 50 pounds. And if it's the same greenness as the rest of the field, then you made the right choice. But if that strip is greener than the rest of the field, then you better amend the rest of the field so it doesn't lag behind and yield.