Crop Residue Management
In this episode, Melissa Bartels and Michael Sindelar talk about crop residue management. What are the benefits of leaving vs. removing crop residue from our fields? Listen to find the answer to this question and more.
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[00:00:02.890]Welcome to "CropWatch Podcast",
[00:00:05.360]a production of Nebraska Extension.
[00:00:11.960]Welcome to the "CropWatch Podcast".
[00:00:14.420]I'm your host, Melissa Bartels,
[00:00:16.230]a cropping system educator with Nebraska Extension,
[00:00:19.300]and today I'll be joined
[00:00:21.100]by cropping system educator Michael Sindelar.
[00:00:23.770]And we'll be talking about crop residue management.
[00:00:27.140]How are you doing today?
[00:00:28.340]Well, to be honest, Melissa, I'm a little confused.
[00:00:30.500]I feel like I'm in the wrong seat, here.
[00:00:32.230]Normally, I'm the one that gets to ask the questions
[00:00:33.933]instead of the one being grilled.
[00:00:37.660]Harvest is almost over here in Nebraska
[00:00:40.700]and there's just a few fields left out there to harvest.
[00:00:44.050]We're gonna switch over to residue management,
[00:00:47.090]how our producers around Nebraska do that.
[00:00:50.230]So, what is the importance of crop residue,
[00:00:52.930]especially during a season like we just had
[00:00:55.330]where we're dealing with some drought
[00:00:56.810]and some moisture issues?
[00:00:58.980]So, the interesting thing is crop residue,
[00:01:01.130]when it's left in place, you have two things going on.
[00:01:03.770]You have what lays down on the ground,
[00:01:05.670]That's referred to as your horizontal residue.
[00:01:08.490]Then you have what's standing up,
[00:01:09.760]and that's your vertical residue.
[00:01:11.350]They have different functions.
[00:01:12.870]Your horizontal residue protects the soil a lot.
[00:01:15.760]Think of it, it's like an impact barrier
[00:01:17.560]for when raindrops come and hit it.
[00:01:19.560]Rain is a very destructive thing to bare soil.
[00:01:22.870]I suggest anybody who has spare time,
[00:01:25.010]take a look at those slow-motion raindrop videos on YouTube.
[00:01:28.790]There are like little crater impacts created by it.
[00:01:31.510]And so, to prevent soil erosion,
[00:01:33.940]you want some kind of physical barrier.
[00:01:36.010]But we don't have anything growing in our off season,
[00:01:38.170]so our physical barrier to prevent that
[00:01:40.560]is our horizontal residue.
[00:01:43.250]You know, you're thinking, okay,
[00:01:44.460]well, I'll just flatten everything down and I'll be good.
[00:01:47.740]Well, it doesn't quite work out that way.
[00:01:49.340]You also need your vertical residue
[00:01:51.320]to keep everything in place.
[00:01:52.870]And our vertical residue is really important,
[00:01:55.190]especially in years like this.
[00:01:56.760]Our vertical residue, think of it as like a catch.
[00:01:58.990]It's standing straight up, and it's teeth.
[00:02:00.510]It's gonna catch and it's gonna hold
[00:02:01.730]our horizontal residue in place
[00:02:03.160]so we don't lose it to the wind.
[00:02:04.880]And then it's also going to help catch
[00:02:07.480]and drift snow into our fields.
[00:02:09.840]And when you think about this year,
[00:02:11.330]we have a really dry year,
[00:02:13.210]so it's really important to try to maximize
[00:02:15.350]that snow catch into our fields
[00:02:17.060]so that we can get some recharge from any type of snow
[00:02:19.850]that we get going into the winter.
[00:02:21.590]The other interesting thing,
[00:02:23.150]I was talking about horizontal residue
[00:02:24.970]as a barrier for water.
[00:02:26.980]It doesn't keep it from going in,
[00:02:28.550]but it protects it from erosion.
[00:02:30.310]But at the same time, very interestingly,
[00:02:32.660]it's a barrier for water coming out of the soil.
[00:02:35.850]And so, it creates a layer in between
[00:02:38.680]the residue and the soil surface
[00:02:41.510]that has a lot more humidity in it
[00:02:43.780]and it makes it so that there's a lot less moisture
[00:02:46.890]lost from the soil,
[00:02:48.530]being evaporated out of the soil into the air.
[00:02:50.710]So, that's another important key thing
[00:02:52.550]about keeping residue into place,
[00:02:54.440]is 'cause it's gonna make it so that your soil
[00:02:56.630]retains its water more.
[00:02:58.170]Now, I know there are some people in the state
[00:03:00.190]that are like, "Oh, well, that's not great.
[00:03:02.167]"I wanna get rid of my water on my field
[00:03:04.237]"as fast as I can for spring."
[00:03:06.120]But at the same time, in the summer months,
[00:03:08.590]you're gonna hurt yourself
[00:03:09.500]because you're gonna be losing water faster.
[00:03:12.270]It really depends on your system.
[00:03:13.920]In a dryland system,
[00:03:15.740]it's really hard not to have that residue into place
[00:03:19.060]because you're relying on rain.
[00:03:21.480]The years like this year where you don't get it,
[00:03:23.700]that residue's just a blessing
[00:03:25.120]because it keeps that moisture in your soil
[00:03:27.940]a little bit longer compared to fields that don't have it.
[00:03:30.870]And then aside from that,
[00:03:32.510]from some of the studies that we've done,
[00:03:34.320]we've seen where when you aggressively remove,
[00:03:37.280]and I'm talking about taking away
[00:03:38.460]more than 60% of the residue.
[00:03:41.700]When we're shredding down and removing the crown stalks,
[00:03:44.880]we saw a loss in fields' ability to infiltrate water.
[00:03:48.490]So, that's water entering into the soil.
[00:03:50.560]It's harder for water to enter in the soil,
[00:03:52.580]enters in at a slower rate.
[00:03:54.170]So, that's gonna increase your risk of erosion
[00:03:56.520]and you're not gonna get water in, you know?
[00:03:58.470]In the spring we get those five-inch rains.
[00:04:01.330]Maybe instead of pulling two, 2 1/2 of those inches in,
[00:04:05.680]now you're only pulling in 1 1/2.
[00:04:08.380]That's not great.
[00:04:09.240]And then we've also seen our water holding capacity.
[00:04:13.010]This is our soil's ability to store water.
[00:04:15.050]So, think of it as a storage tank.
[00:04:17.300]When we remove that residue aggressively,
[00:04:19.180]that storage tank shrank.
[00:04:21.650]So, now we're storing less water for our crops
[00:04:23.700]to use through the year.
[00:04:24.540]So, those are benefits for why you wanna leave
[00:04:26.850]that residue in place.
[00:04:28.890]And then on top of that,
[00:04:30.470]there are nutrients in residue, okay?
[00:04:32.660]Not all of our nutrients are being lost to green.
[00:04:35.380]So, normally a lot of our fertility recommendations
[00:04:38.840]are made based off of just removing green.
[00:04:41.310]Well, when you start removing the residue,
[00:04:43.010]you have to start taking in account the nutrients
[00:04:45.113]that are in residue.
[00:04:46.550]So, our nutrients in residue,
[00:04:48.130]for every ton of residue that you remove,
[00:04:50.110]you're removing about 17 pounds of N from the field,
[00:04:53.030]four pounds of phosphorus, 34 pounds of potassium,
[00:04:57.890]and about three pounds of sulfur.
[00:04:59.380]So that's, you know,
[00:05:00.213]some other things that you need to take in consideration
[00:05:02.210]when you're removing residue.
[00:05:05.253]And so, you talked a little bit about
[00:05:07.170]your vertical and your horizontal residue.
[00:05:09.810]Lately, we've been having some pretty strong winds,
[00:05:13.790]and I've seen a lot of leaves flying around.
[00:05:18.010]So, is there a certain height for that horizontal residue,
[00:05:21.730]or is a little bit enough to hold everything in place?
[00:05:26.940]That's a really good question
[00:05:28.070]and it's very hard to answer,
[00:05:29.840]'cause it's not just height of residue.
[00:05:31.803]Part of that is row orientation.
[00:05:34.080]When you get rows that are orientated
[00:05:36.030]with the direction of the wind blowing,
[00:05:38.040]you're gonna lose your residue
[00:05:39.350]even if you have good vertical residue.
[00:05:42.020]When you're looking at vertical residue,
[00:05:43.870]the taller it is,
[00:05:46.070]the better it is for keeping stuff in the field.
[00:05:49.920]Now, I know that's not necessarily
[00:05:51.360]the best thing for equipment operations.
[00:05:54.100]When you think about height,
[00:05:55.730]maybe think about like what you wanna do.
[00:05:58.550]Grazing is a great way to take care
[00:06:02.120]of some of the height issues.
[00:06:03.300]As cattle move through the field,
[00:06:04.860]they're gonna stomp it down in its place.
[00:06:06.900]But they do remove some of it.
[00:06:09.100]They leave some manure in place with that nutrients
[00:06:11.890]in a different form.
[00:06:13.180]So, I mean, that's another adjustment for it.
[00:06:15.930]I'm dancing around that height.
[00:06:17.540]There is no real magic number
[00:06:19.370]or breakthrough for it, unfortunately.
[00:06:21.700]The whole idea is that you wanna keep something vertical
[00:06:24.950]probably, at least, I would say 12 inches high,
[00:06:29.050]keep stuff in place.
[00:06:30.050]Otherwise, you're gonna lose everything from your field.
[00:06:32.940]One thing I do know
[00:06:34.020]from some of the experiments I've been with corn residue,
[00:06:36.560]we cut stuff down to the soil level for our stalks.
[00:06:40.630]We shredded our stalks down that far
[00:06:43.400]and we left 40% of the residue in the field,
[00:06:47.300]and then wind removed 100% of the residue
[00:06:50.380]after we baled it.
[00:06:51.480]So, we lost all of our residue just because
[00:06:54.260]we didn't have that vertical residue in place.
[00:06:56.740]Yes, we have some wind here in Nebraska.
[00:07:01.640]You did talk a little bit about removing that residue.
[00:07:04.020]So, why are producers interested in removing that residue
[00:07:08.700]if it has so many benefits to leaving it in the field?
[00:07:14.040]Well, people bale residue primarily
[00:07:16.960]as a source of feed for livestock.
[00:07:19.670]So, that's where we're at a conundrum right now, right?
[00:07:22.920]'Cause in a drought,
[00:07:24.860]there's less forages and less feed already generated.
[00:07:28.310]So, now we need more feed for our cattle
[00:07:31.030]and we have less sources,
[00:07:32.150]so now people are looking at,
[00:07:33.690]well, maybe I can bale the stalks out of my field.
[00:07:37.270]This is a hard question
[00:07:38.280]'cause there's really no right answer.
[00:07:39.860]You have to look at what have you been doing,
[00:07:42.940]'cause you can remove quite a bit of residue
[00:07:46.370]from a field once and have no issues.
[00:07:49.640]What you really get into trouble
[00:07:51.120]is where you start removing residue all the time,
[00:07:54.730]or when you're doing it year after year after year.
[00:07:57.720]But yeah, the main reason why people
[00:07:59.660]have been bailing residue is to feed their cattle.
[00:08:03.050]And it pains me.
[00:08:04.250]There is a small yield bump.
[00:08:06.260]There's about a 3% yield increase
[00:08:08.450]when you remove residue in most years,
[00:08:11.410]except for drought years.
[00:08:12.680]Drought years, you actually see a loss in yield,
[00:08:15.450]and that's just due to the fact
[00:08:16.870]that the soil warms a little bit faster
[00:08:19.000]'cause it's drying out a little bit faster in the spring.
[00:08:21.660]So, what are the recommendations for removing residue?
[00:08:25.530]The recommendations for moving residue
[00:08:27.540]is to keep at least 50% on.
[00:08:29.860]I know that's hard.
[00:08:30.980]Like, what is 50% of the residue that's out in the field?
[00:08:34.150]When we look at it for a mass amount,
[00:08:37.530]we see about one ton of residue is produced
[00:08:40.830]for every 40 bushels of corn.
[00:08:43.460]This is generalization.
[00:08:44.920]There are some hybrids that may produce more
[00:08:46.817]and some hybrids that produce less.
[00:08:48.870]We have seen this in some of our research
[00:08:50.630]that some of our dryland varieties
[00:08:52.340]produce a lot less residue
[00:08:53.870]than our center pivot irrigated hybrids
[00:08:57.810]that are selected for different parts of our state.
[00:09:00.530]So, with that,
[00:09:02.130]you wanna at least probably keep 2.5 tons in your field.
[00:09:06.510]Two tons, definitely.
[00:09:07.560]So, what is that looking like?
[00:09:09.790]You wanna get over at least 200 bushels per acre
[00:09:14.230]before you start thinking about removing residue.
[00:09:17.040]Because of that difference between hybrids,
[00:09:19.130]between our rain fed and center pivot irrigated,
[00:09:23.010]we don't suggest removing residue from rain fed systems,
[00:09:26.030]'cause there's just a lot less of it out there.
[00:09:28.630]The other thing is thinking
[00:09:30.050]of your other erosional factors.
[00:09:32.030]When we have steep side slopes,
[00:09:34.320]we definitely recommend keeping residue
[00:09:37.050]in place in those areas as erosion control.
[00:09:40.290]So, really, the recommendations for removing it is,
[00:09:43.910]when you have a irrigated field that's flat
[00:09:47.650]and you're producing over 200 bushels per acre,
[00:09:50.450]try to keep half of that on.
[00:09:52.260]That's not the easiest thing to do with equipment.
[00:09:54.840]Another strategy is every other pass,
[00:09:58.950]'cause sometimes people don't have the option of taking 50%.
[00:10:02.360]What they have for rakes and balers takes 100%.
[00:10:05.540]So, don't take all of the field.
[00:10:08.180]Go every other pass,
[00:10:09.370]and then if you're continuous corn,
[00:10:11.130]take the passes that you didn't take year one in year two
[00:10:13.940]and leave behind what you took from year one in year two.
[00:10:19.270]How about people that are running cattle on stalks?
[00:10:23.040]What I do know from the research I've been part of,
[00:10:25.830]cattle don't have 100% efficiency.
[00:10:28.230]They leave behind stuff, they trample stuff.
[00:10:30.390]There's waste that's left behind them.
[00:10:31.810]So, even the most aggressive grazing,
[00:10:35.300]you'll probably see at least 50%
[00:10:37.960]of the material left behind.
[00:10:39.440]And a lot of what's being left behind is a vertical
[00:10:43.360]or the heavy stalk themselves.
[00:10:45.910]Cattle are really picky.
[00:10:47.270]They're gonna select the stuff
[00:10:48.580]that's actually more likely to be lost to the wind first,
[00:10:51.070]so that's gonna be like the husk, the cob,
[00:10:53.500]and any leftover green.
[00:10:59.300]Is there anything else that you want our listeners to know
[00:11:01.970]about crop residue management?
[00:11:05.280]No, not really.
[00:11:06.640]Tapped out what I can explain just talking about it.
[00:11:10.853]If I wanted to go in more depth,
[00:11:11.686]I would need to show some pictures or something.
[00:11:15.533]So, do you have any programs that are coming up
[00:11:18.550]that are related to this topic
[00:11:20.470]that you want our listeners to know about?
[00:11:23.482]I did talk about soil a lot, and soil erosion control.
[00:11:27.440]I am one of those people that am invested in soil health,
[00:11:31.160]so I'm part of a team of educators
[00:11:33.010]that are working on a statewide soil health conference
[00:11:35.810]that's gonna be put on by Extension.
[00:11:37.430]It's gonna be the Cover Crop and Soil Health Conference,
[00:11:40.930]and we plan to release this
[00:11:43.810]at least via Zoom across the state.
[00:11:47.020]We're hoping if conditions allow for it
[00:11:50.190]to have listening areas across the state,
[00:11:52.700]so there might be a place where you can go view it
[00:11:56.230]and not have to travel to the main host site.
[00:11:59.080]And so, we're planning to actually do this
[00:12:02.150]on February 11th of 2021.
[00:12:05.190]We're really keeping our fingers crossed
[00:12:06.680]'cause we want those listening sites so people can come out,
[00:12:09.500]watch it, and not have to be stuck watching it
[00:12:12.150]via Zoom on your computer at home.
[00:12:14.520]But yeah, we're still waiting
[00:12:16.460]on putting the marketing together for that one.
[00:12:19.540]Right, it is a COVID world, forever changing, right?
[00:12:23.770]Yes, It's not the same.
[00:12:26.723]Well, thank you for joining me today
[00:12:28.840]and we'll catch you next time.
[00:12:31.360]All right, you have a good one.
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