Accounting for Manure Nutrients

Rick Koelsch Author

03/05/2021 Added

161 Plays

Description

From "Manure & Fertilizer: Complementary Roles" portion of Land Application Training 2021

Searchable Transcript

Search:

[00:00:00.640]My name is Rick Koelsch.
[00:00:02.320]I'm with the university,
[00:00:03.910]I have appointment in Bio systems engineering
[00:00:06.720]and animal science.
[00:00:08.580]Tonight we're gonna start off talking a little bit
[00:00:11.220]about the accounting for manure nutrients.
[00:00:14.190]We're gonna focus primarily on nitrogen.
[00:00:17.620]Tonight, we wanna make sure you have the tools
[00:00:20.180]in your back pocket for crediting the nitrogen and manure,
[00:00:25.850]applying it at a rate that is reasonable.
[00:00:30.270]For matching a reasonable rates
[00:00:33.060]for your corn crop or whatever crop you're growing.
[00:00:37.040]So my discussion on the nutrient management.
[00:00:41.490]We're gonna try to accomplish these two items.
[00:00:44.390]We wanna identify the forms of nitrogen in manure
[00:00:49.380]and a little bit of their characteristics.
[00:00:51.990]And particularly what portion of that nitrogen
[00:00:56.070]is available to your corn crop.
[00:00:58.570]How much credit can you feel comfortable,
[00:01:01.230]giving to that product?
[00:01:02.870]We're gonna utilize a lab report to do those calculations.
[00:01:09.380]It's important to recognize that,
[00:01:12.660]in terms of title 130,
[00:01:18.580]it focuses on nitrogen management initially.
[00:01:22.840]And we need to ensure
[00:01:26.090]that the fertility products that we're applying,
[00:01:29.260]whether they be manure or fertilizer,
[00:01:32.390]or the credits that come from sources
[00:01:35.110]such as a lagoon crop from the previous year.
[00:01:39.110]That those are all being accounted for,
[00:01:41.270]and that we are balancing things on a nitrogen basis.
[00:01:45.240]And so as you meet, sit down with your inspectors
[00:01:49.330]that's gonna be one of the important questions
[00:01:51.870]that they're gonna have for you.
[00:01:53.530]Can you document that you've got a reasonable balance
[00:01:56.980]on a nitrogen basis?
[00:01:58.980]Now, title 130 also has some expectations
[00:02:02.820]from a phosphorus standpoint.
[00:02:04.950]And as some of you probably experienced.
[00:02:07.370]As you apply manure and nitrogen based rate,
[00:02:11.860]especially our cattle manures.
[00:02:16.090]We tend to see a buildup in phosphorus in soils.
[00:02:19.870]If we're doing it every year, every other year,
[00:02:24.250]every third year basis.
[00:02:27.140]If that occurs, then phosphorus becomes a risk
[00:02:31.530]and they'll become a parcel point.
[00:02:34.240]It's some fields where we will have to go
[00:02:36.730]to a phosphorus based space.
[00:02:38.240]But we'll be talking more about that
[00:02:40.610]at our final discussion in a week from now.
[00:02:44.520]So tonight we're gonna focus on nitrogen.
[00:02:47.780]Now last week, John had mentioned
[00:02:50.790]some of the different forms of nitrogen that we deal with.
[00:02:55.000]He talked about ammonium nitrogen in particular
[00:02:58.190]and nitrate nitrogen and how they move at different rates.
[00:03:01.510]Ammonium if we recall has a
[00:03:06.350]is charged such as it will attach itself
[00:03:10.480]to the clay particles in the soil.
[00:03:13.180]Nitrate nitrogen has a similar charges
[00:03:16.680]to the soil particles.
[00:03:18.750]And so it tends to wanna move very quickly.
[00:03:24.158]In some of our manures we have a certain portion of that,
[00:03:26.880]that is ammonium.
[00:03:28.500]In the case of our slurry manures like a
[00:03:31.330]deep pit, swine barns, that can be probably 75%
[00:03:36.640]or more ammonium type nitrogen.
[00:03:39.500]The other common part in our manure is the organic nitrogen.
[00:03:44.560]This is simply nitrogen that's bound up
[00:03:47.100]and partially digested feed, in microbiome
[00:03:52.560]biomass that was generated in the gut of the animal.
[00:03:55.920]And these are particles that don't want
[00:03:58.290]to move very much at all.
[00:04:00.400]They're very stable in our soil environment.
[00:04:04.030]And they also are stable in terms of
[00:04:06.840]when they become available to the crop.
[00:04:09.440]They come available at a different rate than the ammonium.
[00:04:13.000]So knowing what's in an organic fraction
[00:04:15.690]versus an ammonium fraction,
[00:04:17.700]is very important to our our planning process.
[00:04:22.230]Now, many of you I think or all of you
[00:04:24.490]may be dealing with a solid manures, be it feedlots.
[00:04:28.687]And our manure is gonna look more like this.
[00:04:32.180]It's gonna be 75 to 90% organic nitrogen.
[00:04:37.570]And the balance being primarily ammonium nitrogen,
[00:04:40.530]but a small fraction ammonium.
[00:04:43.460]And all of you are probably dealing with
[00:04:45.670]some kind of a holding pond,
[00:04:47.480]that's collecting the runoff water from your open lots.
[00:04:52.490]And that in most cases is gonna be primarily ammonium,
[00:04:56.580]some organic end.
[00:04:58.520]And there is gonna be quite a bit of variability
[00:05:01.000]of that too.
[00:05:01.833]I've seen holding pond water from the same farm,
[00:05:05.710]just two different years,
[00:05:07.110]it's gone from 25% ammonium that to 75% ammonium.
[00:05:12.580]I tend to see it more on this side.
[00:05:16.100]But it really doesn't matter the proportions,
[00:05:18.570]but being able to read a manure analysis
[00:05:22.260]and separate out that ammonium
[00:05:24.650]versus that organic nitrogen is very important.
[00:05:28.390]This organic nitrogen becomes available to a crop
[00:05:31.930]at a very slow rate.
[00:05:34.330]The ammonium nitrogen is very much like
[00:05:37.320]our ammonium in urea based fertilizers.
[00:05:39.610]It becomes available pretty quickly,
[00:05:41.830]once that soil gets above 50 degrees.
[00:05:45.090]So recognize that difference in the product, okay.
[00:05:50.520]Now, we're going to
[00:05:53.830]learn what fraction is ammonium
[00:05:56.227]and organic from a manure analysis.
[00:06:00.040]So I hope you've seen these before,
[00:06:01.930]but if you haven't, let's just take a minute
[00:06:03.970]to look at this very, very closely.
[00:06:08.510]There are generally several columns of data
[00:06:13.700]or rows depending both on the lab that you're using.
[00:06:18.140]For different nutrients sources.
[00:06:23.100]And we've got to figure out which of these columns,
[00:06:26.820]we would like to use here.
[00:06:29.813]There is a dry basis analysis on a part per million,
[00:06:34.440]which is at left hand.
[00:06:36.250]A dry basis that's more on a pounds per ton.
[00:06:39.000]And as is basis available first year nitrogen.
[00:06:45.480]We would probably wanna use something on an as is basis,
[00:06:49.730]cause that we're dealing with pounds per ton.
[00:06:52.590]And we don't know it as a dry product.
[00:06:55.520]We know how many tons we're applying
[00:06:59.030]as a wet product.
[00:07:00.380]So either of those last two columns
[00:07:03.560]might be what we lean towards.
[00:07:06.700]So do we wanna know as is, in total or available?
[00:07:12.760]Now, if the laboratory did a good job of guessing
[00:07:17.340]how you're managing that manure when you apply it,
[00:07:20.530]you probably could get by with that last column.
[00:07:24.240]But what I'm gonna suggest tonight,
[00:07:26.630]is we're gonna use that third column.
[00:07:29.080]That as is basis total nutrients
[00:07:33.110]and then you make the determination
[00:07:35.730]what becomes available from that.
[00:07:38.200]Based upon how you might be farming.
[00:07:41.520]So that is the column that's most important.
[00:07:47.330]In terms of nutrients, we're gonna spend some time
[00:07:51.040]primarily on these tonight.
[00:07:53.740]The top ones in terms of the organic ammonium nitrogen.
[00:07:57.950]First two rows, we'll also pull out the numbers
[00:08:01.500]for phosphorus and potassium.
[00:08:05.745]So note, what those numbers are, have those handy,
[00:08:08.180]because we'll be turning to using those in just a second.
[00:08:12.440]Now the exercise I'm gonna ask you to walk through,
[00:08:16.100]and you're gonna need to do this work.
[00:08:20.060]Do some of the calculations here,
[00:08:22.370]is you're gonna to detect those as is numbers,
[00:08:27.920]and convert them into what is truly crop available.
[00:08:33.410]And we're gonna do it for an examples.
[00:08:35.310]For the feedlot, we're going to apply manure
[00:08:38.870]at a 20 ton rate, put it on in March.
[00:08:44.590]And we're gonna incorporate it within two days.
[00:08:47.910]So keep that information in mind.
[00:08:51.820]I want you to make an estimate of what's available.
[00:08:57.620]I want you to answer these three questions.
[00:09:02.260]I want you to find the value of the nitrogen
[00:09:05.060]that's available to this year's crop.
[00:09:08.070]I want you to look out at what that nitrogen
[00:09:10.890]in this year's crop or in this year's manure
[00:09:13.950]may actually be available into future years.
[00:09:17.610]And then I want, we wanna also estimate
[00:09:19.570]the P and the K credit.
[00:09:21.820]So we're gonna accomplish those things.
[00:09:25.180]So go in and grab that ammonium
[00:09:28.480]and that organic nitrogen value from your manure
[00:09:32.950]and that phosphorus and potassium.
[00:09:35.460]Here's the NebGuide.
[00:09:37.990]And we're just gonna skip through most of it.
[00:09:42.430]I wanna come to this worksheet that's on the last page.
[00:09:45.880]Let's go through and do the calculations.
[00:09:48.560]Step one of this is gonna start at the top
[00:09:51.230]and we're gonna ask how the manure is measured.
[00:09:55.369]And I'm gonna be doing this on a ton per acre basis
[00:09:58.241]or pounds of nutrients per ton.
[00:10:00.680]So everything's gonna be measured on a ton unit.
[00:10:02.930]So I'll just click on that or you can check it.
[00:10:07.040]So that's my first step.
[00:10:09.050]My second step is I'd like to know what the total quantity
[00:10:15.300]of nitrogen that we've applied.
[00:10:18.620]And this calculation is gonna break out
[00:10:22.070]the ammonium on the left, the organic in the middle,
[00:10:29.340]and then either looking back in the past
[00:10:32.440]or into the future we can go either way.
[00:10:36.080]The total organic nitrogen from past applications
[00:10:39.900]or looking forward.
[00:10:41.120]And we'll show you how that works in just a second.
[00:10:44.440]All right, so let's go ahead and fill that in.
[00:10:48.120]Our application rate was 20 ton per acre,
[00:10:54.210]ammonium fraction.
[00:10:56.140]See, I believe it was 1.9
[00:10:59.770]step and fall, yeah 1.9.
[00:11:04.010]So we'll go ahead and plug that in.
[00:11:08.310]And so it's done the math for me.
[00:11:10.360]20 times 1.9 gives me the 38 pounds
[00:11:14.570]of total ammonia nitrogen that's available.
[00:11:18.810]We'll do that the same on the organic.
[00:11:21.170]20 tons times.
[00:11:23.710]We're dealing with 16.3 pounds per ton.
[00:11:29.470]And so the total nitrogen is showing here
[00:11:32.750]for organic it's 326, so a lot of organic.
[00:11:36.930]Now I'm gonna come back to the organic nitrogen.
[00:11:40.990]Well let me do one thing here,
[00:11:42.970]let's assume two years ago
[00:11:47.770]you put on 30 tons the manure
[00:11:52.370]and let's assume that you had done this at
[00:11:58.971]and let's use the same organic nitrogen values we just used.
[00:12:04.230]We'll assume it was in the same ballpark.
[00:12:06.460]So we put on 30.
[00:12:08.690]Two years ago we put on 489 total, okay.
[00:12:12.630]So that's step two here.
[00:12:15.480]Now, not all of this nitrogen is gonna be available
[00:12:20.690]and so that's our next step.
[00:12:22.390]Is to determine what is available.
[00:12:27.670]If you're in that NebGuide,
[00:12:29.110]you just slip up to right above that table.
[00:12:33.080]And it has this graphic that helps us identify
[00:12:38.580]what is available.
[00:12:41.330]You'll notice on the left-hand side is the ammonium nitrogen
[00:12:45.310]right-hand side is the organic nitrogen.
[00:12:49.000]And so we've got to pull out of this table
[00:12:51.910]and availability factor.
[00:12:54.390]So if you look in the ammonia fraction,
[00:12:57.590]which of these best describes our situation?
[00:13:01.150]We're pre-planning manure and incorporating,
[00:13:05.370]and we use the example,
[00:13:06.780]we're incorporating it two days later.
[00:13:09.180]So it looks like right here,
[00:13:13.903]is a set a numbers, I would look at most closely.
[00:13:18.270]And there are three availability factors.
[00:13:22.240]One is for solid manure, one is for liquid manure.
[00:13:26.140]Below 50 degrees and above 50 degrees is the third column.
[00:13:30.360]So we're dealing with solid manure.
[00:13:32.020]So our value is right here.
[00:13:35.540]So we're gonna suggest,
[00:13:37.020]that whatever ammonium nitrogen we applied,
[00:13:39.500]we use a availability factor, 25% or 0.25 for the ammonium.
[00:13:46.920]Over here on the organic side,
[00:13:49.840]it's really only gonna vary by the product we're putting on.
[00:13:54.760]So we're using a beef or dairy product, solid.
[00:13:59.010]And it looks like we're gonna use
[00:14:01.160]a similar availability factor for the organic fraction here.
[00:14:06.890]So recall those numbers
[00:14:09.660]and let's move back to our calculations here.
[00:14:16.020]So now we're gonna jump down to step three.
[00:14:20.010]It's already brought down,
[00:14:21.460]the value of the total nitrogen that was applied here.
[00:14:26.710]The case of the ammonia was 38 pounds.
[00:14:29.810]And if we incorporate it within two days
[00:14:32.140]we said that availability factor was 0.25.
[00:14:36.260]So I'm only gonna get 10 pounds
[00:14:38.670]of ammonium nitrogen out of that application.
[00:14:43.640]On the organic nitrogen, that middle column.
[00:14:47.730]Again, I'm using the 0.25 for feedlot manure.
[00:14:53.086]And I've got 82 pounds of nitrogen
[00:14:58.560]that came from that product.
[00:15:03.240]If I had applied manure two years ago at that 30 ton rate
[00:15:08.710]It's also suggesting that there's an availability factor
[00:15:11.730]for that manure of 7% and I forgot to
[00:15:15.430]point that out up here.
[00:15:17.730]In that organic side you may have seen
[00:15:21.370]in the corner of that graphic, what's available next year.
[00:15:29.360]Two years from now and three years from now.
[00:15:31.460]And so that 7% value came from right here.
[00:15:39.560]So it's already looked up that 7% value added it in.
[00:15:44.700]Come up with 34 pounds from two years ago.
[00:15:49.460]And now in order to determine what credit,
[00:15:52.870]I would want to give to that manure,
[00:15:55.750]I'd add up my ammonium nitrogen, my organic nitrogen,
[00:16:00.780]any residual nitrogen from previous years.
[00:16:04.780]And that total is the credit I would give to manure.
[00:16:09.730]Now, many of you, I'm guessing work with a consultant
[00:16:15.610]that may do all of this calculations for you in advance.
[00:16:20.520]And if that's the case, that you've got a target to aim for,
[00:16:24.940]you got a target of 20 tons, that's gonna be a good rate.
[00:16:28.750]But that was calculated based on a manure sample,
[00:16:32.550]probably from a year ago or a history of manure samples.
[00:16:36.830]Now, you know, that that manure,
[00:16:39.340]you're pulling out of those lots is quite variable.
[00:16:42.400]And so if we see it 16 pounds per ton available
[00:16:46.920]from organic side this year.
[00:16:49.410]Next year it might be 10.
[00:16:51.210]The following year it might be 20.
[00:16:53.910]And so because of that availability or that variability,
[00:16:58.910]you need to be able at the last minute
[00:17:01.380]when you get that last manure sample.
[00:17:04.720]Or when you've checked in the field
[00:17:06.580]that actual application rate that
[00:17:09.784]you were able to put on
[00:17:11.260]that may not have been that 20 ton to the acre.
[00:17:14.070]You actually do those calculations.
[00:17:16.230]So, you've got this number adjusted
[00:17:19.950]to this year's situation.
[00:17:23.000]And that may tell you, well
[00:17:25.600]we came up a little short on nitrogen.
[00:17:27.520]I may have to put some supplemental nitrogen on
[00:17:30.610]at planting or post-planting at some point in time
[00:17:34.730]if I have that capability.
[00:17:36.900]Or I may have put on too much nitrogen
[00:17:40.220]and I may need to back off at planting.
[00:17:43.200]So by doing these calculations yourself,
[00:17:46.920]you can make an adjustment in terms of
[00:17:50.000]what this number truly is for this year.
[00:17:53.370]And if there's some adjustment
[00:17:55.040]that you need to make in other fertilizer applications.
[00:17:59.980]Before we leave the nitrogen side,
[00:18:02.130]I'm gonna run back up here.
[00:18:04.210]And I'm gonna change my calculation here.
[00:18:09.300]And I'm gonna suggest, we ought to know,
[00:18:13.790]if there's value in future years from this year's manure.
[00:18:19.890]So this year I put on 20 ton and we said, it's 16 pounds.
[00:18:25.700]I'm just gonna put in 16 pounds
[00:18:27.930]of organic nitrogen per ton.
[00:18:31.160]And so this allows me to look into the future.
[00:18:37.200]And so for those numbers we just used,
[00:18:41.730]the calculations have already been done here,
[00:18:44.390]looking to the future.
[00:18:46.660]So my 20 tones is worth roughly 50 pounds
[00:18:50.740]of nitrogen next year, 23 pounds two years from now.
[00:18:56.860]13 pounds, three years from now.
[00:18:59.400]So at least next year and possibly two years out.
[00:19:02.930]You may wanna consider that
[00:19:04.350]as part of the crediting process.
[00:19:07.780]And it gets down to a fairly small number
[00:19:10.240]in three years and out.
[00:19:11.420]And whether you wanna consider that,
[00:19:14.390]I'll leave that up to you.
[00:19:16.670]So that's looking forward.
[00:19:20.130]Now I'm gonna go back to zero here.
[00:19:23.850]So we don't see those down below.
[00:19:29.430]And we're gonna finish up this calculation.
[00:19:35.120]I'd like to now know what's in the phosphorus
[00:19:37.557]and the potassium side.
[00:19:40.130]20 pounds has phosphorus,
[00:19:44.790]and
[00:19:46.690]14 pounds has potassium.
[00:19:50.530]Same 20 ton rate, got an availability factor in here.
[00:19:55.660]Most of it's gonna be available.
[00:19:57.260]And if, in many circumstances I would just consider
[00:20:00.940]the 100% availability, but if we wanna stay conservative,
[00:20:04.540]we'll use these numbers.
[00:20:06.610]And you can see you have 280 pounds
[00:20:09.310]of phosphate fertilizer accessible to your crop.
[00:20:13.960]Now this crops probably you're gonna use
[00:20:15.970]60 to 70 pounds in the first year.
[00:20:18.870]So you may have three, four, five, six years of phosphorus
[00:20:24.360]depending upon how your corn crop is yielding here.
[00:20:27.780]And you'll probably ask some excess potassium as well.
[00:20:32.070]So bottom line,
[00:20:35.500]we have 91 pounds of nitrogen
[00:20:38.180]by going through this calculation.
[00:20:41.160]For this 20 ton rate with 16 pounds of organic nitrogen.
[00:20:46.340]Two pounds of ammonium nitrogen.
[00:20:48.550]Got 21 pounds of nitrogen, 91 pounds of nitrogen.
[00:20:53.130]288 pounds of phosphate, 224 pounds of potassium.
[00:21:00.390]So that's what
[00:21:04.110]I would wanna do every year,
[00:21:06.630]when you've got that final application rate.
[00:21:09.500]You've got that final manure analysis.
[00:21:11.950]So you can check what is truly available to your crop.

The screen size you are trying to search captions on is too small!

You can always jump over to MediaHub and check it out there.

Comments

0 Comments

Accounting for Manure Nutrients

Description

Searchable Transcript

Comments icon comment

Related Channels

Comments