Episode 129 - Brad's Nutrient Management Plan for WCROC Pastures - UMN Extension's The Moos Room
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Brad: Welcome to The Moos Room. It's just Brad today, which could be really dangerous. Joe and Emily are out traveling, probably on airplanes, right now. They left me alone, which means I could talk about whatever I want because they're not here policing it. I could say Hereford and Jersey and add to the numbers, but I guess, we'll behave today. We wanted to answer a listener question. I'll talk a little bit about that and maybe a few other things that's happening from a forage perspective here at our research center. Question comes from Kevin Dietzel is a loyal listener and dairy grazer. We've had him on the podcast before.
Kevin Dietzel: Hello, Moos Room. This is Kevin Dietzel from Hamilton County, Iowa. I have a couple of questions for mostly Brad about nutrient management things. First off, what do you do with your bedded pack manure? Do you compost it first, or do you spread it straight onto the field? Does any go onto pastures? Second question, what is your overall nutrient management strategy for pastures? Do you soil sample regularly? What kind of fertilizers do you use and so forth? Do you have a different strategy for organic pastures versus conventional pastures? All right. Thanks. Bye.
Brad: Our bedded pack barn, so many of you know, we outwinter our cattle. We generate a lot of manure with our straw packs for our out-wintering cows, as well as our compost-bedded pack barn. We bed with chopped straw. We don't really use sawdust anymore. We don't use sawdust anymore for maybe two reasons. One is cost. It's really costly out here in western Minnesota to truck a lot of sawdust in.
The second reason is we are finding that the sawdust or chopped wood shavings were tying up the nitrogen in our corn. We'd spread it on the land, and it takes nitrogen to break down the wood, and we were seeing reduced corn yield. We really stopped with the sawdust and the shavings. We use a little bit, but not a lot. With our compost packs, we actually let them compost before we spread them on fields or pastures.
It depends on how much manure we need, but if I think about it today, our compost-bedded pack barn as well as our out-wintering piles from this past winter, so we took cows off of those wintering lots late April, so they've been composting. They're composting with the straw and manure, and we're pushing it up, probably not as much as what we should. Maybe once a month trying to get it to turn, to heat up.
We also have a clay compost area where we compost a lot of our straw and manure, as well as we generate a lot of straw and manure from our hog barn. We have a deep-bedded farrowing barn and have pigs that are in outdoor straw packs. We have a lot of manure, and that's composted as well. We really like to compost it for about six months before we spread it on the fields, probably in the fall is typically when we spread a lot of this. Our cows come out April, early May.
We compost and spread it in the fall after we've harvested corn or soybeans. A lot of it goes on our organic land because that's our really only nutrient source for our crops, but we also spread it on some of our conventional land as well. We don't have to use a lot of nitrogen fertilizers because we're generating enough manure from our cattle and our pigs here at our research center.
In a nutshell, we let it compost, helps break down some of that straw that's in there, and provides a really good nutrient source. The downside of that is we generate a lot of flies. Flies love to be in the compost. That's where stable flies lay their eggs. The biting flies that are on cow's legs that bite them, that's from straw packs more than likely or debris. There's a trade-off that we have to decide. We want good fertility for our land, but we also generate some flies from that. It's not a perfect situation, but we continue to compost that.
The other question goes with our nutrient management plan with our pastures. Well, I believe in soil sampling our pastures to see what's there. Now, we will sample them maybe every three to five years. It's probably been about three years since we really did some extensive soil sampling on our pastures. Once in a while, we take individual pastures if we have a feeling they're low and something not generating as much grass, so we'll sample those sporadically.
This spring, I did a full soil analysis on all of our pastures. We have nine pastures for our milking cows that we sampled. I grid sampled them, took many different subsoil samples down to six inches around each pasture that we have and sent them to-- We use Midwest Laboratories. There's many different laboratories that you can use to send those in. I recommend you soil sample your pastures because it might provide some insight into what's going on.
Some of these were not really what I expected. We have one pasture that we have Kernza on. It's a Kernza and alfalfa that we use for grazing. We don't harvest grain, so we use it mostly for grazing, and it produces good forage. It was starting to go down in production maybe a little bit, so we sampled it. It was quite interesting. Actually, the organic matter was about 4.0, and that's in our Kernza pasture.
Some of our other pastures are close to almost 7% organic matter, but this Kernza pasture was very low in phosphorus, so not much phosphorus availability at all. It was low in potassium. Actually, high in magnesium and calcium. We probably need some phosphorus on this pasture to help keep the grass growing and get good production. We'll use that probably from our manure. This fall, we'll probably spread some composted manure. We have some liquid hog manure that we can spread on the field as well.
We'll probably maybe use a combination to increase the phosphorus level of the pastures. It needs some help. It's pretty low in nitrates as well, so we don't have many nitrates in that pasture. That one maybe needs a little help, and I wouldn't expect it. The forage, it looks good. We've grazed it a couple times here already this year, but you never know Some of the other pastures, like I said, they're pretty high in organic matter.
They'll range from 4.6 to almost 7. It depends on the pasture. Some of our pastures are pretty low in phosphorus, some are really high in phosphorus. It just depends on cattle loads on those. All of our pastures are good for magnesium and calcium, so we really don't need to add any of that. Our soil pHs are 7.4 to 7.8. One thing that we've also noticed, if you look at the surface nitrogen or nitrate nitrogen, it's pretty variable, quite low across most of the pastures, so we don't really have a big nitrogen issue, not from a runoff standpoint. Some of our pastures actually could use some nitrogen.
If you look at some of the other minerals in there that we consider when we're grazing, our pastures are low in sulfur, they're high in zinc, low in manganese, very high in iron. Western Minnesota, there's lots of iron. They're high in copper, medium for boron. We might consider putting some sulfur on our pastures. If you look at our soil fertility recommendations that we got from our soil sampling, it says that our pastures could use a little nitrogen and some phosphate. Now, not all of them could use some phosphate, but some could.
The Kernza pasture that I was talking about says that we could use some nitrogen, some phosphate, some potash, and some zinc. How are we going to do that? Well, we're pretty much going to use manure that we generate from our cows or pigs. We have tended not to use any other fertilizer sources. All of our pastures are organic, so we pretty much have to use manure. Now, you could use some synthetic fertilizers and such if you're not organic.
They work, but we have to think about it differently and use the resources that we have, and that's manure. We're going to go into these fields, spread probably our composted manure on our pasture, maybe some liquid dairy lagoon water that we have in the fall, and probably do some reseeding as well into these pastures to try and increase legumes, grasses, things like that.
That's where we sit with our nutrient management plan. I like to use manure. We don't do anything on our other pastures. It's pretty much cows. Stocking rates of cows, I use the cows to put manure on pasture. If I need a little more in certain places, well, we can increase the stocking rate and keep the cows there for a little bit longer. I think it's pretty essential that we use our cows to be able to spread manure and make an even distribution across our pastures.
All that fertility helps with our pasture growth. We're exploring a lot of different forages for our pastures and how to increase actual legumes in there. We have a project going on now with the University of New Hampshire that's looking at increasing legumes in our pastures. Red clover, we're using white clover, bird's-foot trefoil, kura clover, and alfalfa to try and increase the diversity of our pastures. Our pastures here, some are very diverse, some are not quite monoculture but don't have much diversity in them.
A lot of them are brome grass pastures. The pastures that are doing great have orchard grass, fescue, and some red clover in it. That tends to be my mix of choice right now is meadow fescue, orchard grass, red clover, maybe a little bit of alfalfa in there. We're trying to increase the legumes in our pasture, and it's going well. We're finding the red clover does well here where we're at. Red clover is a great forage. The cows love it. They can do well off of it.
We probably don't want as much in our pasture. We're using about six pounds per acre of that in our pastures. The kura clover is great. We have a lot of kura clover in our pastures that some researchers had planted many years ago. It spreads very well, and it's very hardy if you can get it established. Getting it established can be a challenge, but the cows really love kura clover and do well on it, and it blends right in. Makes a very good diverse pasture with fescue and orchard grass and even some of the brome grasses.
We're looking at that of another graduate student. She'll probably join us on the podcast here a little bit, tell us what she's doing, but she's been planting some forages with our solar systems to try and see which do well in more shade and in the sun, planting some clovers and monoculture along with other grass species. It's an interesting project that's happening, trying to look more at how we can increase our forage production in our pastures.
It's difficult. I was on a farm last week that has irrigation as well, and, man, the pastures were beautiful, diverse fescues, orchard grasses, clovers, chicory. It was wonderful being out in those pastures. There's a lot of good things about irrigation that can be done. We don't have irrigation in our pastures, so it can be a challenge in the hot weather that we're seeing right now. We're going to keep going with some of this research on grazing and looking at fertility.
I'm a firm believer in rotating some of our pastures, maybe ripping them up, re-seeding, interceding grasses and other species in there to keep them going. They need help. They can't keep going without some help, either fertility or additional seed in the seed bank. That's what we're doing here in Morris. Keep going with that. We'll probably wrap that up today. Pay attention the next few weeks.
We got some guests coming on. We'll have some of my grad students talking about a few of their projects, also looking into some beef sustainability issues. Some other dairy producers might join us. Keep listening. We'll see where we're going. I suppose I wrote down the stuff today that I'm supposed to say so I can remember. I know I've screwed it up before.
If you have any questions about what we're doing, you want to talk to Joe or Emily, you can email all of us at themoosroom@umn.edu. That's T-H-E-M-O-O-S-R-O-O-M@umn.edu or you can leave us a voicemail, 612-624-3610. Let us know if you'd like to hear any topics that we should discuss or anything that you'd like to hear about. We will talk to you again.
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