Sustainable Vegetable Production from the Land of Corn and Hogs
Ajay Nair, Professor and Extension Vegetable Specialist, Iowa State University
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05/22/2024
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Description
This seminar will focus on research conducted in the area of sustainable vegetable production and will provide a quick snapshot of the agriculture industry in Iowa. Research topics would include cover crops, conservation tillage, integrated systems, and soil amendments such as biochar.
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- [00:00:00.000]The following presentation
- [00:00:02.220]is part of the Agronomy and Horticulture seminar series
- [00:00:05.790]at the University of Nebraska Lincoln.
- [00:00:08.310]All right, I'd like to welcome everybody this morning.
- [00:00:10.797]It is my absolute pleasure to introduce Dr. Ajay Nair.
- [00:00:15.810]Dr. Nair currently serves as professor
- [00:00:18.330]and Extension Vegetable Specialist at Iowa State
- [00:00:21.030]and will take on responsibilities as their department head
- [00:00:23.640]for horticulture in July of this year.
- [00:00:26.370]Dr. Nair has a very active extension program
- [00:00:29.969]reaching out, working with stakeholders and growers
- [00:00:33.120]all across the state of Iowa.
- [00:00:35.250]In addition to having an active teaching program
- [00:00:37.980]and an active research program,
- [00:00:39.660]his most recent project, I believe, is Agrivoltaics
- [00:00:43.140]in application to fruit and vegetable production.
- [00:00:46.710]He has over his time at Iowa State
- [00:00:50.049]mentored 48 graduate students,
- [00:00:51.390]and today he's joining us and will be talking about
- [00:00:53.790]sustainable vegetable production
- [00:00:55.170]in the land of corn and hogs.
- [00:00:56.850]Dr. Nair, thank you.
- [00:00:57.870]Thank you so much, thanks.
- [00:00:59.730]It has been a wonderful time so far here in Lincoln.
- [00:01:05.598]Last time I visited here was in 2010,
- [00:01:10.040]so it's been 14 years, and Christian was generous enough
- [00:01:13.500]to wait to have dinner with me at 9:00 PM.
- [00:01:17.340]Because I teach a lab and the lab ended at 5:30,
- [00:01:20.137]9:00 PM I was here, but Christian was willing to go with me
- [00:01:22.830]for dinner, so thank you for doing that.
- [00:01:24.810]And many familiar faces here.
- [00:01:26.640]Dr. Paul Reed, been in touch with him
- [00:01:29.670]and know him for a long time.
- [00:01:32.070]Several other people came.
- [00:01:33.330]Stacy and Joe M. Lewis from the entomology department.
- [00:01:38.179]Joe and I went to undergrad together in India,
- [00:01:41.580]so nice to see Joe also here.
- [00:01:43.680]So again, a big thank you for inviting me
- [00:01:46.620]to present some of the research findings and extension work
- [00:01:50.520]which we have conducted at Iowa State University
- [00:01:53.700]in the area of vegetable production,
- [00:01:54.990]but we all know where we belong, right?
- [00:01:58.176]Corn and soybeans still rule the land.
- [00:02:02.010]So what is happening in the area of horticulture?
- [00:02:04.920]Even though there are more acreage
- [00:02:06.600]when it comes to corn and soybean,
- [00:02:07.770]but there is sliver of horticulture in each and every state.
- [00:02:11.940]So should I, okay,
- [00:02:17.070]Perfect.
- [00:02:17.903]So make sure the hogs are there.
- [00:02:19.350]And another reason I have hogs is
- [00:02:21.750]I went to school at Michigan State
- [00:02:23.850]and we had an undergraduate student club
- [00:02:26.340]and it was called HOGS.
- [00:02:28.320]Horticulture Organization of Graduate Students.
- [00:02:31.290]So horticulture is still there.
- [00:02:33.660]So agriculture rules, right?
- [00:02:36.310]Where would you find something like this
- [00:02:38.970]where the tractors have the same status
- [00:02:41.310]and the same value as a car in a parking lot?
- [00:02:44.670]So agriculture it is in Nebraska, in Iowa, in many places.
- [00:02:49.170]So we are proud to be in a place
- [00:02:51.120]where agriculture is revered and valued
- [00:02:54.360]and a significant portion of our economic engine.
- [00:02:58.170]So this is Iowa agriculture,
- [00:03:00.290]so it's about a $30 billion industry,
- [00:03:02.920]maybe a few billion more.
- [00:03:05.059]This is a 2-year-old data.
- [00:03:07.080]If you can see most of the pie here is filled with blue,
- [00:03:12.690]which is livestock and poultry products.
- [00:03:16.050]And you have the yellow, which is the grain, corn, soybean,
- [00:03:19.350]but you still have that sliver.
- [00:03:20.790]Remember the sliver I was talking about?
- [00:03:22.470]That's here, we have that sliver here, 0.1% of horticulture.
- [00:03:27.060]But these are high value crops.
- [00:03:28.980]You don't need to grow 500 acres of peppers
- [00:03:33.150]or tomatoes to make a living.
- [00:03:34.410]Growers can still make a living in five acre,
- [00:03:37.050]even in one acre,
- [00:03:38.010]depending on how they grow their vegetables
- [00:03:39.540]in a high tunnel and other intensive production systems.
- [00:03:41.820]So horticulture is still alive.
- [00:03:44.190]Oh, sorry, corn still rules.
- [00:03:46.980]And there are many uses of corn.
- [00:03:48.570]You know, this is something which I stole from the web.
- [00:03:51.150]I mean, look at the amount of energy spent in here
- [00:03:54.630]and the art, and using corn for making corn maze.
- [00:03:58.770]This is from Casey's.
- [00:04:00.210]They sponsored this corn maze one of the years.
- [00:04:03.660]But at the same time, when you go to your state fair,
- [00:04:07.110]these are some pictures from Iowa State Fair,
- [00:04:09.240]where we know, I'm sure many of you go there to judge
- [00:04:11.910]fruits and vegetables,
- [00:04:13.020]the quality of the vegetable that comes through that arena,
- [00:04:16.470]it's outstanding.
- [00:04:18.780]You can see some tomatoes, peppers, onions,
- [00:04:23.700]okra, more onions there.
- [00:04:26.250]And the most important picture,
- [00:04:28.410]the person, this is this person here, right?
- [00:04:31.350]We need those young minds.
- [00:04:32.880]We need those young people to get hooked to horticulture,
- [00:04:35.520]and learn about horticulture, and know what horticulture is.
- [00:04:38.190]So we are able to keep that pipeline flowing.
- [00:04:43.020]So in at the state fair,
- [00:04:44.940]horticulture is front and center.
- [00:04:47.220]Look at this, the competition,
- [00:04:49.080]does the Nebraska State Fair have a competition
- [00:04:52.110]of like biggest pumpkin?
- [00:04:53.400]Is there something like that, Sam?
- [00:04:55.854]So we have this thing called the big pumpkin competition.
- [00:04:59.490]So you can see this one, Dave Davis,
- [00:05:01.920]I did work with them, I know this grower,
- [00:05:04.980]and you can see the amount, 795 pounds.
- [00:05:08.712]This is the second prize, 717 pounds, 606 pounds.
- [00:05:12.780]So what I want to say here
- [00:05:14.600]is that horticulture is front and center,
- [00:05:16.260]and we have to take that effort
- [00:05:17.490]to make sure horticulture is out there.
- [00:05:19.530]The Department of Horticulture sponsors this event partly,
- [00:05:21.992]and so our name is there,
- [00:05:24.129]so people know what horticulture is.
- [00:05:26.430]That's, I think the question which I hear the most.
- [00:05:29.190]Most of the people don't know what horticulture is.
- [00:05:32.340]So yes, we are front in line.
- [00:05:34.320]This is the hot from the press data.
- [00:05:37.200]If you have not gone there yet, please do so.
- [00:05:39.600]This is the 2022 ag census.
- [00:05:43.020]So this was out maybe four or five days back.
- [00:05:46.440]So you can go there, look at the statistics for Nebraska,
- [00:05:48.990]your state, I pulled data for Iowa.
- [00:05:52.290]We are not a very big state
- [00:05:53.580]when it comes to vegetable production.
- [00:05:56.070]It's about 7,590 acres,
- [00:05:59.310]and of those vegetables, sweet corn is the first one,
- [00:06:03.090]about 3000 acres.
- [00:06:05.040]Green peas, 793 acres, pumpkin, beans.
- [00:06:08.700]So those will be the top four.
- [00:06:09.840]Potatoes, we have squash here.
- [00:06:11.640]That's also in the Cucurbitaceae family, which is up there.
- [00:06:14.040]So these are the vegetables
- [00:06:15.510]that are having significant acreages,
- [00:06:17.670]and many of these vegetables are large scale production.
- [00:06:20.700]You think about sweet corn, think about pumpkins,
- [00:06:23.820]and because of that, I showed you some pictures
- [00:06:26.092]of agritourism.
- [00:06:26.925]That's where the momentum is being built up.
- [00:06:30.480]Another area which we see growth in Iowa is peas,
- [00:06:35.460]sweet peas.
- [00:06:36.300]Processing peas.
- [00:06:37.230]So we have the company Bird's Eye,
- [00:06:39.510]which is based in Minnesota.
- [00:06:41.010]They are contracting with farmers in Iowa
- [00:06:43.200]to grow a thousand acres of sweet peas.
- [00:06:45.240]Almost the same amount for sweet corn.
- [00:06:47.460]So I think that's the way we can push horticulture
- [00:06:50.400]into larger acreages
- [00:06:51.750]by having those processing contracts.
- [00:06:54.450]So my role, my lab there in the department
- [00:06:59.370]is focusing on sustainable vegetable production.
- [00:07:02.040]And there are several projects
- [00:07:03.600]and several areas we work on.
- [00:07:07.110]Just like any other small horticulture department,
- [00:07:09.450]we are one person deep in each area.
- [00:07:11.970]So I'm a vegetable specialist, we have a fruit specialist,
- [00:07:15.150]we have a greenhouse specialist.
- [00:07:16.620]There's only one person.
- [00:07:17.700]So we have to do many things.
- [00:07:19.230]I'm sure Sam and Christian
- [00:07:20.370]are all also doing several things.
- [00:07:22.710]When it comes to vegetables, it's not just one area.
- [00:07:25.260]So my lab focuses on conservation tillage,
- [00:07:28.410]and I'll share some of the research results
- [00:07:30.030]from that research, which is ongoing for several years now.
- [00:07:34.050]So cover crops is the central theme.
- [00:07:35.640]We do a lot of cover cropping projects, high tunnels,
- [00:07:38.610]integrated pest management, focus on soil quality, grafting,
- [00:07:42.660]more of a pest management strategy for high tunnels,
- [00:07:45.720]and of course nutrient management.
- [00:07:47.130]And then we do work on some unique crops
- [00:07:50.430]that are not grown in Iowa much,
- [00:07:52.530]so sweet potato is one of them.
- [00:07:54.420]Many growers are interested to grow sweet potato
- [00:07:56.880]on raised bed, black plastic mulch.
- [00:07:59.190]And it grows decent, decent growth.
- [00:08:02.400]We can get local sweet potatoes.
- [00:08:04.170]So local markets are looking for that.
- [00:08:05.990]So there is value there.
- [00:08:09.450]And again, this definition of sustainable agriculture,
- [00:08:12.120]I know you can define it many ways,
- [00:08:14.640]and sometimes it's people say, oh,
- [00:08:16.350]I don't even know what that means.
- [00:08:18.090]But this is from a grower in a town called Anita, Iowa.
- [00:08:22.267]"A sustainable agriculture is the shock absorber
- [00:08:24.720]of the swinging pendulum."
- [00:08:26.250]And so we should, at least in my lab,
- [00:08:29.250]we work with commercial growers,
- [00:08:31.050]we work with organic growers,
- [00:08:32.250]but we also work with the middle folks,
- [00:08:33.840]which are the sustainable growers,
- [00:08:35.160]sustainable vegetable growers.
- [00:08:36.360]So I think that's the mindset,
- [00:08:38.610]that's the lens we should approach
- [00:08:40.920]if we want to get more sustainable acreages
- [00:08:43.620]in vegetable production.
- [00:08:45.570]So when we talk about vegetable production,
- [00:08:48.268]this is true for many growers out there,
- [00:08:51.630]they have to manage several things.
- [00:08:53.340]It's not just one.
- [00:08:55.830]You think about biodiversity,
- [00:08:57.390]think about crop rotation,
- [00:08:58.590]especially to avoid many of those soil-borne diseases.
- [00:09:01.560]Early blight, talk about septoria in tomatoes,
- [00:09:04.625]food quality, pest and disease, soil health,
- [00:09:08.130]nutrient management, soil microorganisms.
- [00:09:10.380]There is so much out there in flux.
- [00:09:12.720]So as a grower, they're juggling all of this
- [00:09:15.450]in a growing season for a crop.
- [00:09:17.430]And they might have many of those crops out there.
- [00:09:20.640]So I will talk a bit more in detail about sustainability
- [00:09:24.390]from the cover crop standpoint,
- [00:09:26.550]and that will focus more on conservation tillage
- [00:09:28.785]in vegetable production systems.
- [00:09:32.010]So this is conventional tillage.
- [00:09:35.910]So what is conventional tillage?
- [00:09:36.960]There are benefits when you till the ground.
- [00:09:39.325]You can incorporate residue, you can terminate weeds,
- [00:09:43.410]increases soil temperature,
- [00:09:45.120]allows the use of plasticulture.
- [00:09:46.860]So that's the staple when it comes to vegetable production.
- [00:09:50.970]Raised bed, plastic mulch, drip irrigation.
- [00:09:53.640]So that's the benefit.
- [00:09:54.480]What are some disadvantages of conventional tillage?
- [00:09:58.290]Increased nitrate leaching.
- [00:09:59.430]We all talk about more nitrates
- [00:10:03.060]going down the river to Gulf of Mexico.
- [00:10:05.970]There's an Iowa nutrient reduction plan.
- [00:10:08.190]We are trying our best, but still there's a lot of nitrate
- [00:10:10.620]in the water.
- [00:10:11.453]So can we reduce that?
- [00:10:12.750]And you can take small steps at a time.
- [00:10:14.400]So this is one way, can we use conservation tillage,
- [00:10:16.530]reduce tillage to make that possible?
- [00:10:20.346]With the disadvantage of conventional tillage, again,
- [00:10:23.940]is the less infiltration or compaction
- [00:10:27.420]and plow plan issues.
- [00:10:29.160]And of course erosion is up there,
- [00:10:31.590]especially if growers till in the fall,
- [00:10:34.440]and they have a big rain event in the fall or in the spring,
- [00:10:37.170]a lot of that top soil washes away.
- [00:10:39.720]So that's the conventional tillage.
- [00:10:41.700]What we are going to focus on
- [00:10:42.990]is more of a cover crop based strip-tillage,
- [00:10:46.230]where you have your vegetables growing in rows.
- [00:10:48.870]And I'll have more pictures as we move on,
- [00:10:51.270]but we don't till everywhere.
- [00:10:53.460]We just till a strip.
- [00:10:55.380]And in that strip we transplant our vegetable.
- [00:10:59.220]And the cover crops, which were seeded
- [00:11:02.010]the previous season we laid down.
- [00:11:04.350]And that cover crop acts as a mulch in the middle.
- [00:11:07.620]So reduced tillage, we did till the small strip,
- [00:11:10.410]but did not till the entire ground.
- [00:11:13.260]And plus we had a cover crop in the fall.
- [00:11:15.390]So we have that organic matter that we are building up
- [00:11:17.970]as we move on.
- [00:11:21.120]Plants in there.
- [00:11:21.953]And then then the middle is the mulch.
- [00:11:24.630]This is from Dr. Dan Brainard from Michigan State.
- [00:11:26.940]Dan does a lot of work in the conservation tillage area.
- [00:11:29.580]A great researcher focuses on different things.
- [00:11:32.160]And so we work together,
- [00:11:34.230]have worked together on several projects.
- [00:11:36.810]So if reduced tillage is the way to go,
- [00:11:40.470]if we know that there are benefits of reduced tillage,
- [00:11:43.230]why are growers not using it?
- [00:11:45.450]What are some impediments?
- [00:11:47.850]One is the lack of specialized equipment for vegetables.
- [00:11:50.790]And that's true even when coming for spraying,
- [00:11:53.640]or especially for tillage,
- [00:11:54.690]we don't have those specialized equipment
- [00:11:56.340]which growers can use to manage a system
- [00:11:59.520]with reduced tillage.
- [00:12:00.810]Weed management and high residue.
- [00:12:02.340]You can look at the residue that we have generated
- [00:12:05.880]with the cover crop rye.
- [00:12:07.710]And how do you manage to till in this
- [00:12:11.340]or manage weeds in this, if weeds come through it?
- [00:12:15.060]When you use reduced tillage systems,
- [00:12:16.240]there is loss of earliness,
- [00:12:18.450]because the soil temperature primarily is lower
- [00:12:21.000]in such systems because of having that mulch.
- [00:12:23.520]This is a pumpkin experiment
- [00:12:25.950]where we are demonstrating strip-tillage with pumpkins.
- [00:12:29.310]Great for weed suppression.
- [00:12:30.450]You can see there's no weeds.
- [00:12:31.440]And as the season progresses, there was no weed moving on.
- [00:12:33.990]There were few weeds here and there,
- [00:12:35.130]which we had to manually weed,
- [00:12:36.570]but otherwise a great system for pumpkins.
- [00:12:40.260]So these are some impediments.
- [00:12:41.765]So for a reduced tillage system,
- [00:12:44.370]for a grower to adopt that,
- [00:12:45.690]the first thing they have to achieve,
- [00:12:47.310]and we have to help them, is to understand
- [00:12:49.620]that you have to treat your cover crops seriously.
- [00:12:53.550]It's not just any crop that you just go and harvest
- [00:12:56.190]at the end of the fall whenever you have time,
- [00:12:58.380]after your main crop is harvested.
- [00:12:59.730]You have to plan for it.
- [00:13:01.140]So if it's middle of September, is it end of September
- [00:13:03.740]or is it beginning of October?
- [00:13:05.250]Is the land properly prepared?
- [00:13:07.440]Is the drill in good shape,
- [00:13:09.360]so it's putting the seeds at the right depth?
- [00:13:11.790]So this is drilled a Tye Pasture Pleaser,
- [00:13:16.261]which is a no-till drill,
- [00:13:18.362]where we used cereal rye, right depth.
- [00:13:22.230]And you can see how the emergence of cover crop is perfect.
- [00:13:24.600]And this is what we want.
- [00:13:25.740]We don't want uneven performance of cover crop,
- [00:13:28.410]because if the cover crop is not even,
- [00:13:30.360]next year when you try to roll it
- [00:13:32.280]and you you want to use it as a weed suppression tool,
- [00:13:34.950]it doesn't work.
- [00:13:35.783]And then there's no point of blaming the cover crop,
- [00:13:37.890]because we did not take proper care
- [00:13:39.810]of seeding the cover crop.
- [00:13:41.850]This is an example of what could happen
- [00:13:44.460]if you don't treat your cover crop that well.
- [00:13:47.010]This is at the Muscatine Island Research Farm at Iowa State.
- [00:13:50.430]And what are some things you see here
- [00:13:52.980]in this rolled rye?
- [00:13:56.370]Soil, and whenever you see soil, there are gonna be weeds
- [00:14:00.000]that are going to come out from there.
- [00:14:02.700]So the purpose of using the cover crop for mulch,
- [00:14:04.950]it's already defeated because you have soil there,
- [00:14:07.710]and in this case it's poor establishment.
- [00:14:10.590]Seeding rate was an issue.
- [00:14:13.140]And also this is a sandy soil.
- [00:14:15.450]So we underestimated that.
- [00:14:16.950]We thought, okay, cover crop,
- [00:14:18.180]why should we fertilize a cover crop?
- [00:14:19.920]We should not.
- [00:14:20.910]But what we have learned now,
- [00:14:22.350]if it's a sandy soil,
- [00:14:23.580]if you want a decent cover crop biomass,
- [00:14:25.620]which you want to suppress the weeds,
- [00:14:28.514]you might have to fertilize the cover crop
- [00:14:31.110]maybe 25 to 30 pounds per acre of nitrogen in the fall.
- [00:14:34.350]If we would've done that,
- [00:14:35.880]the story would have been different.
- [00:14:38.160]So treating cover crop seriously is absolutely critical.
- [00:14:42.390]This is at the AIM site at Iowa State,
- [00:14:45.210]and this one, great strand of cereal rye.
- [00:14:48.660]This is in May, middle of May.
- [00:14:51.510]That's when the rye goes to anthesis.
- [00:14:53.700]And by anthesis, what I mean is that the pollens are flying,
- [00:14:58.410]the rye is in the reproductive phase.
- [00:15:01.110]So at this stage we can kill the rye by roller crimping,
- [00:15:05.577]and and that's a tool which we use in our lab.
- [00:15:08.100]We could spray glyphosate, that's fine too,
- [00:15:10.500]but for organic growers, they cannot use a herbicide.
- [00:15:14.130]So they roller crimp.
- [00:15:15.420]So we will use a roller crimper
- [00:15:17.010]and we will roll this rye for that mat
- [00:15:20.670]for growing the vegetables.
- [00:15:21.750]So this is a roller crimper.
- [00:15:24.720]Many of you might have seen this or know about this.
- [00:15:27.420]This is about 10.5 feet wide,
- [00:15:30.538]chevron shaped blade.
- [00:15:33.390]It crimps the cover crop at three different places,
- [00:15:36.660]so that cover crop doesn't come back, it dies.
- [00:15:38.517]And then we are filling it with water to make it more heavy
- [00:15:43.290]so that there's no chance of the rye coming back.
- [00:15:45.750]Because we have heard stories where somebody rolls the rye,
- [00:15:49.080]and the next day the wind blew in the opposite direction
- [00:15:51.120]and the rye stands up
- [00:15:52.440]and the grower will say, "The rye did not die."
- [00:15:54.240]So we have to say you have to take all the measure you can
- [00:15:57.680]to kill that rye.
- [00:15:59.370]So in this video you can see we are using the roller crimper
- [00:16:05.359]and going over that standing rye.
- [00:16:09.300]You have to go slow.
- [00:16:10.710]I cannot be a race car driver.
- [00:16:13.140]It'll not kill the rye that well, but go slow.
- [00:16:16.440]You can see Dana, my grad student, he is going through it.
- [00:16:21.270]And this will create an amazing mat of rye
- [00:16:25.740]that will eventually die and serve
- [00:16:27.570]as that weed protection mass out there.
- [00:16:32.220]So you can see no soil visible, which is great.
- [00:16:37.500]We don't want to see the soil.
- [00:16:39.150]What we want to see is that thick mat of rye.
- [00:16:41.820]And you will notice when I pick this rye,
- [00:16:44.730]it is crimped in three different places
- [00:16:47.400]that make sure that the xylem is cut off,
- [00:16:50.250]there's no water intake that's going to happen,
- [00:16:53.250]and rye will not come back.
- [00:16:55.870]So that issue of rye coming back is taken care of.
- [00:16:59.190]You'll see that here, it crimps it three places.
- [00:17:02.313]There is one here, it crimped it here further down,
- [00:17:06.360]it crimped it here,
- [00:17:07.830]and then one more it crimped it here,
- [00:17:10.230]so that will take care of the rye.
- [00:17:14.460]So with this research, this is one of the research
- [00:17:17.940]I'm showing from the reduced tillage.
- [00:17:19.560]One of the questions we had, or growers had was,
- [00:17:22.470]okay, first they want to see a side-by-side comparison
- [00:17:24.780]of what happens when we till, no-till, or we use strip-till,
- [00:17:28.500]or we use conventional till without plastic.
- [00:17:31.106]We are not comparing plastics here.
- [00:17:32.490]And the next question they had was,
- [00:17:34.950]okay, how should I apply my fertilizer?
- [00:17:36.960]An organic fertilizer,
- [00:17:38.370]I use this dehydrated chicken manure
- [00:17:40.860]as a fertilizer tool.
- [00:17:42.660]How can I add it?
- [00:17:44.070]Should I add everything at once or should I split it?
- [00:17:49.860]So conventional vegetable extension specialists
- [00:17:54.300]will say, definitely split the nitrogen.
- [00:17:56.550]Nitrogen should not be applied all at once.
- [00:17:59.130]But in organic systems,
- [00:18:00.690]we wanted to see whether it makes sense.
- [00:18:02.327]So we applied everything at once,
- [00:18:05.220]whatever it weighed, it was 120 pounds per acre
- [00:18:07.470]of nitrogen at that rate, all at once.
- [00:18:09.660]And then one treatment was splitting the fertilizer
- [00:18:13.110]into two, applying two third in the first
- [00:18:15.360]and the remaining one third as drip irrigation.
- [00:18:20.610]And we used fish fertilizer as a later supplement
- [00:18:23.550]in that case.
- [00:18:24.807]And a no fertilizer treatment.
- [00:18:26.327]So this is the rye that that's been rolled.
- [00:18:28.590]We are using the Holland Transplantar,
- [00:18:31.470]students are back there
- [00:18:32.790]transplanting and putting the broccoli in there.
- [00:18:35.670]In such systems there could be challenges.
- [00:18:37.680]This is not always a rosy system
- [00:18:39.990]where everything looks nice and clean.
- [00:18:42.205]There are issues.
- [00:18:43.207]For example, if the strip-till was not done properly,
- [00:18:46.200]you might have more clods.
- [00:18:47.760]And then when you put the transplant you have air pockets,
- [00:18:50.850]and so the transplant won't establish that well.
- [00:18:53.010]The other thing which we learned in this system was,
- [00:18:56.070]you saw the high residue system when the rye is rolled,
- [00:18:58.920]it is very difficult to make a strip in that mass,
- [00:19:01.980]in that big mulch.
- [00:19:03.690]And we used the Hiniker strip-tiller,
- [00:19:05.610]and it'll go through, which has a coulter in the front,
- [00:19:07.950]it has a shank, it has a roller basket,
- [00:19:10.380]but the rye will just get entangled
- [00:19:12.060]and just pull the whole mass together.
- [00:19:13.620]It won't till.
- [00:19:15.060]So what we have now done is we seed the rye
- [00:19:17.880]in the fall, September.
- [00:19:19.440]We make the first pass in the fall
- [00:19:21.780]with that strip-tiller, sometime end of October,
- [00:19:24.330]beginning of November.
- [00:19:25.470]If we are not able to do that, that's fine.
- [00:19:27.660]Then in March, at this time
- [00:19:29.838]when the rye has still not started to grow,
- [00:19:32.160]then we make a pass.
- [00:19:33.826]Rye is very small at this point, only this high.
- [00:19:35.220]So we use this Hiniker strip-tiller for that.
- [00:19:37.410]So that's the way we avoid having this heavy residue
- [00:19:40.140]and not having a good strip in there.
- [00:19:43.260]You can see in this one it's okay,
- [00:19:45.530]we do pack the transplants well,
- [00:19:47.662]but this will be completely dead in few weeks,
- [00:19:52.380]and then your plants keep growing.
- [00:19:55.440]So this is later in the season,
- [00:19:57.090]this is the strip stilled plot.
- [00:20:01.082]There are still some weeds.
- [00:20:02.130]It's not a weed free system.
- [00:20:03.720]You can see there are some grasses coming out here.
- [00:20:06.240]There's weeds sometimes in the middle,
- [00:20:07.950]within the row, because that's where you strip-till.
- [00:20:11.190]This is a strip-till plot.
- [00:20:13.290]This is the no-till plot,
- [00:20:14.730]where we created very minimal strip to put the transplant.
- [00:20:18.360]And then we have the conventional till,
- [00:20:22.830]where there was a cover crop,
- [00:20:24.210]but that was completely tilled under this.
- [00:20:26.460]So we had a couple of crops in here.
- [00:20:28.080]We are focusing on broccoli here,
- [00:20:30.360]at the back we have peppers to evaluate both of them.
- [00:20:35.070]So what did we find?
- [00:20:36.962]So this is the weed biomass data.
- [00:20:40.541]So this is the weed biomass on the X axis
- [00:20:43.560]and this is the conventional till, no-till, and strip-till.
- [00:20:47.610]And so one thing, the blue color
- [00:20:49.380]stands for the between row area,
- [00:20:51.420]so that's where the rye was,
- [00:20:53.070]and the in-row is where we made the strip.
- [00:20:55.639]So we see that the blue bar definitely is higher
- [00:20:58.080]and significantly higher.
- [00:20:59.790]So more weed biomass in the conventional till.
- [00:21:03.301]Same thing here.
- [00:21:05.040]Maybe not much statistical difference,
- [00:21:06.660]but we do see that the between-row is definitely higher,
- [00:21:12.134]between-row and in-row are definitely higher
- [00:21:14.550]in the conventional till as compared to no-till
- [00:21:17.310]and strip-till.
- [00:21:18.800]So we are able to manage the weeds.
- [00:21:19.633]We are able to keep them down, knock them down.
- [00:21:22.290]Occasionally we do have to come and pull
- [00:21:24.000]some of the perennial weeds that keep coming,
- [00:21:26.280]so we do have to go in there.
- [00:21:29.010]So those are some numbers there of significance.
- [00:21:33.150]Again, if you compare this conventional till here
- [00:21:35.578]between the row versus strip-till,
- [00:21:37.980]statistically significant difference
- [00:21:39.480]in terms of weed biomass.
- [00:21:41.910]Now the other question which growers always talk about
- [00:21:45.570]is the soil temperature.
- [00:21:47.160]What is the difference in soil temperature
- [00:21:49.440]in these systems between different tillages?
- [00:21:51.750]So if you look at the mean temperature,
- [00:21:54.090]we collected a bunch of data,
- [00:21:55.200]but if you look at the mean temperature,
- [00:21:56.700]you can very clearly see that the strip-till
- [00:21:59.250]and the no-till, the mean temperature is lower than
- [00:22:04.230]this upper row here, which is the conventional till.
- [00:22:06.960]So definitely conventional till has higher soil temperature,
- [00:22:09.780]just because of the soil being tilled or microbial activity.
- [00:22:13.497]And that will promote plant growth.
- [00:22:16.710]Statistically significant.
- [00:22:17.910]You can see that both years, the strip-till no-till,
- [00:22:20.400]but there's no difference between strip-till and no-till.
- [00:22:22.710]That is very similar.
- [00:22:23.940]So I think if given a choice,
- [00:22:26.100]I would prefer using strip-till,
- [00:22:27.330]because in no-till there are more challenges
- [00:22:30.570]of establishing that transplant in the soil.
- [00:22:34.734]When it comes to soil moisture, didn't find any difference
- [00:22:37.610]at the 15 centimeter depth.
- [00:22:41.010]You can see no significant difference.
- [00:22:42.570]But the second year you see significant differences
- [00:22:45.510]where the strip-till and the no-till
- [00:22:48.300]has higher soil moisture,
- [00:22:50.010]so they're able to conserve more moisture in the soil.
- [00:22:53.190]So it works.
- [00:22:54.360]Now with a caveat, our no-till and the strip-till
- [00:22:59.100]are annual treatments.
- [00:23:00.600]We are moving plots.
- [00:23:01.860]We are not in one area year after year,
- [00:23:04.410]just because of the rotation thing.
- [00:23:06.060]We cannot put the same crop in the same place.
- [00:23:08.010]So this is kind of a yearly, one time, no-till strip-till,
- [00:23:12.000]next year we move to a different plot.
- [00:23:13.650]So the weed history of that plot
- [00:23:16.350]will also dictate the results.
- [00:23:18.180]If it was a plot that had a lot of weeds,
- [00:23:20.550]weed seed bank is very high, you might not get that result
- [00:23:23.670]with the strip-till, no-till,
- [00:23:25.080]as compared to a plot that was relatively clean.
- [00:23:29.417]So one of the ways we horticulturists
- [00:23:30.420]get away from that is we follow corn and soybean.
- [00:23:33.390]Because those plots are relatively clean,
- [00:23:36.360]and that way we don't have much weed pressure.
- [00:23:41.730]Okay, what about the broccoli yield?
- [00:23:43.920]So if you split it based on tillage itself,
- [00:23:47.820]you can see here that yield was higher
- [00:23:50.820]in the conventional till,
- [00:23:51.990]just because of the fact soil warming is more,
- [00:23:54.990]and the strip-till and the no-till were similar.
- [00:23:57.810]Another year there was no difference.
- [00:24:00.300]Strip-till and no-till performed
- [00:24:01.740]the same way as the conventional till.
- [00:24:03.720]So there is promise in the system.
- [00:24:05.460]So it can perform very similar
- [00:24:07.020]to what a conventional system looks like.
- [00:24:09.240]And in terms of fertility,
- [00:24:10.320]this was a very useful information
- [00:24:15.780]that we gathered from this research,
- [00:24:17.550]is preplant, all applied at once, split application,
- [00:24:22.650]and this is the no fertilizer, obviously that's always low,
- [00:24:24.930]the yield is low, but there is no difference
- [00:24:27.030]between pre-plant and split.
- [00:24:29.430]So we tell our growers now,
- [00:24:31.260]if you are using that dehydrated chicken manure,
- [00:24:34.410]there's no need of splitting anything.
- [00:24:35.820]You apply everything all at once in the beginning.
- [00:24:38.430]Because it's an organic product,
- [00:24:40.470]it takes time to decompose.
- [00:24:42.030]The soil microbes have to act on it,
- [00:24:43.620]the soil temperature has to be conducive enough
- [00:24:46.110]for that breakdown.
- [00:24:47.709]So don't hassle, don't worry about fertigation
- [00:24:49.740]and other things.
- [00:24:51.255]You apply everything at once
- [00:24:52.200]and you'll get the same results.
- [00:24:53.550]You can see here and here.
- [00:24:55.350]There's no difference if you apply everything preplant.
- [00:24:59.692]So again, coming back to that picture,
- [00:25:02.310]which I showed you earlier.
- [00:25:03.270]So conservation tillage obviously is one of the tools
- [00:25:06.330]that you can use, or a grower could use for sustainability.
- [00:25:09.450]But face the reality, there will be weeds,
- [00:25:11.970]it'll not be a weed free plot.
- [00:25:13.890]There will be weeds, you have to scout,
- [00:25:16.200]you have to pull some of those big weeds out by hand.
- [00:25:19.170]We are right now focusing on some organic herbicides,
- [00:25:23.130]clove oil, vinegar in the greenhouse system
- [00:25:25.980]to see whether, can we spot treat them,
- [00:25:28.590]so that the grower can have a backpack
- [00:25:30.120]and just spot treat those weeds in such systems?
- [00:25:36.030]So summarizing the results there from our work.
- [00:25:40.650]Good establishment of cover crop is critical.
- [00:25:42.570]Timing of strip-till is critical
- [00:25:44.520]so that you have that nice strip.
- [00:25:46.380]Use of quality transplants.
- [00:25:47.910]Now if you don't use quality transplants,
- [00:25:49.800]whatever you did in the field will not make any sense.
- [00:25:52.950]The transplants were poor, they had aphids on them,
- [00:25:56.010]or they had issues, the root system was not well.
- [00:25:58.920]So growers have to still focus on growing
- [00:26:01.830]good quality transplants.
- [00:26:03.390]And of course managing soil fertility, it's critical.
- [00:26:05.820]With that, what I mean is,
- [00:26:07.230]right now if you look at the vegetable,
- [00:26:09.420]commercial vegetable guides
- [00:26:11.070]for recommendations for nitrogen, that's what's out there.
- [00:26:14.250]There is no specific recommendation
- [00:26:15.780]for reduced tillage systems.
- [00:26:17.760]That's where we're thinking about,
- [00:26:19.500]should we add a little bit of nitrogen for cover crop?
- [00:26:21.750]Should we add a bit more nitrogen for the crop
- [00:26:24.210]during the growing season
- [00:26:25.470]because there's a cover crop there?
- [00:26:27.270]So I think those are some areas we are focusing on.
- [00:26:32.370]Sticking on the topic of cover crop,
- [00:26:34.980]I'm switching gears, but still cover crop.
- [00:26:37.140]This is another grower generated question
- [00:26:41.586]where we talk about legumes as a cover crop.
- [00:26:45.409]As researchers, we talk to our students,
- [00:26:47.640]we talk to growers, extension,
- [00:26:49.440]we talk about using Rhizobium, like inoculating our seeds.
- [00:26:54.510]It's a legume, there is a symbiotic relationship.
- [00:26:57.450]So you need to do that.
- [00:26:58.530]And the growers would say,
- [00:26:59.707]"Oh, I had soybean here last year,
- [00:27:01.740]I don't have to worry about it."
- [00:27:03.650]And then we would say, well that's not the case.
- [00:27:06.180]Soybean, the rhizobium that forms
- [00:27:08.010]that symbiotic relationship with soybean,
- [00:27:11.910]rhizobium fredii is different than rhizobium leguminoserum.
- [00:27:15.390]So you need to understand
- [00:27:17.130]that you need to use the right inoculum,
- [00:27:18.750]but we wanted to generate some data
- [00:27:20.670]of what happens, first between inoculation
- [00:27:24.150]versus non-inoculation.
- [00:27:25.350]So this was a Leopold funded study at Iowa State
- [00:27:28.020]where we did an experiment
- [00:27:29.790]where we had three different cover crops,
- [00:27:33.030]inoculated, non-inoculated, same plot,
- [00:27:35.910]grown throughout the year in one growing season.
- [00:27:38.490]Biomass taken and looked at, what is the difference?
- [00:27:41.700]So these are some pictures from that plot.
- [00:27:44.988]This is yellow clover.
- [00:27:48.227]This is yellow clover, one of the replications,
- [00:27:50.610]you have one non inoculated.
- [00:27:52.547]You can see the plant.
- [00:27:53.944]This is the inoculated plant,
- [00:27:56.610]or plants that came out from the inoculated plot.
- [00:27:58.980]You can see a huge difference,
- [00:28:00.450]especially in terms of root growth
- [00:28:02.490]and a lot of those nodules on those root.
- [00:28:06.810]So this is a very, very, very extension based work,
- [00:28:09.600]that you told me this, I did this,
- [00:28:11.287]look what what we see in the field.
- [00:28:13.470]So we can see that in pictures,
- [00:28:15.897]I pulled them outside to see a bit more differences.
- [00:28:18.870]Again, non inoculated versus inoculated
- [00:28:21.578]and also some numbers.
- [00:28:22.919]So when we did the biomass,
- [00:28:25.041]and we just took rough math,
- [00:28:27.420]back of the envelope kind of calculation, round them,
- [00:28:30.660]look at the nitrogen content and did the math
- [00:28:32.910]with respect to the biomass.
- [00:28:35.185]And what we see here is that if you look at this column,
- [00:28:39.417]which is the nitrogen contribution,
- [00:28:40.250]these are the cover crops, crimson, red and yellow.
- [00:28:43.500]And so you see differences in the cover crop
- [00:28:45.840]based on the nitrogen input they can provide
- [00:28:47.880]in a vegetable production system.
- [00:28:49.800]Red clover did the best, about 104 pounds per acre.
- [00:28:53.460]But in terms of this here, this subplot factor, inoculation,
- [00:28:57.240]inoculated versus non inoculated, we see that difference.
- [00:29:00.540]We see that the inoculated ones,
- [00:29:01.950]based on the biomass
- [00:29:02.850]and the back of the envelope calculation,
- [00:29:04.710]more nitrogen can be added in that system
- [00:29:07.980]versus non inoculated.
- [00:29:09.390]And it's easier to tell the growers
- [00:29:11.497]to understand this economic sense of it.
- [00:29:16.080]That packet which we use for rhizobium inoculation,
- [00:29:20.310]it costs about $7 to $8, which will do 50 pound seed.
- [00:29:23.910]So that $7 to $8 is going to go a long way,
- [00:29:27.180]because for legumes, usually it's about 15 to 20 pounds.
- [00:29:30.030]You can do two and a half, three acres.
- [00:29:31.830]So that one packet can easily do three acres.
- [00:29:34.920]So that's really good return on investment.
- [00:29:40.812]So we tell them, use it.
- [00:29:42.120]Never underestimate the power
- [00:29:44.070]of the rhizobium and inoculation.
- [00:29:47.310]This is Ray Cruzi.
- [00:29:48.150]Ray now works as the local food coordinator
- [00:29:51.060]in Dubuque County.
- [00:29:51.893]It's the same plot we were collecting biomass,
- [00:29:54.930]and Ray was spending a lot of time in the plot,
- [00:29:57.870]and some of the other students,
- [00:29:58.800]and as we are just moving on very quickly.
- [00:30:00.960]And we came back, and so he was trying, he found a plant,
- [00:30:03.630]and he kept digging the root,
- [00:30:05.250]and he kept digging and digging,
- [00:30:06.480]and he pulled the whole plant out.
- [00:30:08.910]And this was, and how many of you
- [00:30:10.350]have worked in the fields and pulling roots?
- [00:30:11.910]It's not an easy job
- [00:30:13.673]after some time you feel like, oh, just pull it,
- [00:30:15.527]whatever is out there.
- [00:30:17.550]But he followed
- [00:30:18.600]and it's interesting to see,
- [00:30:20.190]you can see this crimson clover,
- [00:30:23.160]look at the length of that root.
- [00:30:25.170]So we might be under underestimating the value
- [00:30:28.770]of these cover crops by just looking at the top,
- [00:30:31.470]or just the foliage.
- [00:30:33.030]But the value it brings for us in the soil
- [00:30:36.360]in terms of microbial activity, in terms of organic matter,
- [00:30:39.540]in terms of exudates that it puts out, it's amazing.
- [00:30:42.600]It's really valuable.
- [00:30:43.710]So definitely legumes are, especially for organic growers,
- [00:30:46.950]it's critical to invest in legumes
- [00:30:49.920]and treat them like a real cash crop.
- [00:30:53.460]So another project on cover crops,
- [00:30:56.820]we're still on cover crops, this is our timeline.
- [00:31:00.208]For a growing season we have,
- [00:31:03.660]growers will grow their cash crop in the spring.
- [00:31:06.420]They will primarily grow their broccoli, their lettuce,
- [00:31:09.969]all this planted here, radishes.
- [00:31:13.470]And those are typically, if you think of broccoli,
- [00:31:16.873]usually middle of April, by middle of June, broccoli is out.
- [00:31:19.560]And then the growers have another window
- [00:31:22.290]to put their vegetables in.
- [00:31:24.030]And that is in July, end of July, beginning of August,
- [00:31:27.780]they'll put the fall crop.
- [00:31:29.400]So then there is this window here,
- [00:31:31.590]that middle of June till the beginning of August,
- [00:31:34.350]that one and a half month.
- [00:31:36.120]What can be done there?
- [00:31:37.650]So some growers came to us and said,
- [00:31:39.570]hey, can we grow some summer cover crops?
- [00:31:42.300]We know rye, we know hairy vetch,
- [00:31:43.860]we know some of the clovers which will over winter,
- [00:31:46.740]but what about cover crops
- [00:31:47.790]that are in the middle of the summer?
- [00:31:49.980]And we do have some time, that 45 day period
- [00:31:52.830]where we can grow that.
- [00:31:54.090]So can we do that?
- [00:31:55.530]Can we find something and use that for our benefit?
- [00:31:59.250]So this is Moriah Bilenky.
- [00:32:02.040]She graduated from my lab, she's now faculty at Purdue.
- [00:32:04.063]So this is Moriah's project.
- [00:32:05.970]So due credit to her, she focused on that.
- [00:32:08.905]She came up with the experiment and hypothesis,
- [00:32:11.220]and we talked about what cover crops should we use.
- [00:32:14.400]So we had different questions out there.
- [00:32:16.830]Our hypothesis was, if we use grass cover crops,
- [00:32:20.220]we think that they will improve weed suppression.
- [00:32:22.174]Hands down.
- [00:32:23.970]Summer cover crops will provide nitrogen for fall vegetable.
- [00:32:26.667]And that was one of the hypothesis.
- [00:32:28.446]We looked at labile carbon,
- [00:32:30.585]and talking about more about nitrogen,
- [00:32:33.720]may be more available later in the season
- [00:32:35.820]under a grass cover crop as compared to legume.
- [00:32:38.766]So I'll show you some data, not all of them,
- [00:32:40.740]but this is the list of the cover crops we used,
- [00:32:45.406]we studied.
- [00:32:47.370]These are summer cover crops.
- [00:32:48.600]They will not winter, they will not over winter.
- [00:32:51.202]Sun hemp, which is primarily Florida
- [00:32:54.090]grows a lot of sun hemp there.
- [00:32:56.610]Danielle Treadwell, she's a researcher there.
- [00:32:58.230]She does a lot of work in that area.
- [00:33:00.000]Teff, this is a relatively new cover crop,
- [00:33:02.910]Eragrostis tef from Africa.
- [00:33:07.613]And we are very impressed with teff.
- [00:33:09.060]It's a great cover crop, does a really good job
- [00:33:11.430]in that one and a half month period.
- [00:33:13.410]We used buckwheat, many growers are familiar with that.
- [00:33:16.800]Golden flax, something new.
- [00:33:18.660]A brown top millet, again,
- [00:33:19.830]not a standard cover crop to grow.
- [00:33:21.660]Sorghum Sudangrass.
- [00:33:22.740]This is definitely increasing in popularity.
- [00:33:26.100]And then mungbean and also cowpea.
- [00:33:29.010]Because it's a legume, it grows really well
- [00:33:31.050]in our weather conditions.
- [00:33:33.030]So this is what the crops look like, that plot looked like.
- [00:33:36.810]Each of these plots are 30 feet by 30 feet,
- [00:33:40.170]different cover crops all randomized.
- [00:33:42.579]So at the time of termination we are collecting the biomass,
- [00:33:46.290]we are taking quadrats in there to look at weeds,
- [00:33:49.290]how much weeds are there, numbers, biomass of the weeds.
- [00:33:52.500]And later on we grew different crops.
- [00:33:54.390]We grew beetroots and we grew cabbage in these.
- [00:33:58.830]So I'm gonna focus more on the weed aspect of it.
- [00:34:01.770]So one thing to highlight here
- [00:34:04.320]is in terms of the biomass of the cover crop,
- [00:34:09.270]brown top millet and you can see buckwheat,
- [00:34:14.220]they did pretty well.
- [00:34:15.420]6.5, 5.6.
- [00:34:17.730]But look at this one here, sorghum sudangrass and teff.
- [00:34:21.300]Equally good.
- [00:34:22.320]Actually sorghum sudangrass was the highest,
- [00:34:25.080]7.2 tons per acre.
- [00:34:26.370]And anybody grown sorghum sudangrass?
- [00:34:29.463]Okay, I see, okay, yeah, so you know it creates
- [00:34:33.720]a lot of biomass.
- [00:34:34.830]And you can mow it,
- [00:34:36.570]and it comes back with a vengeance.
- [00:34:38.670]It wants to grow more.
- [00:34:40.080]So you can keep it growing.
- [00:34:41.850]We are just harvesting it one time.
- [00:34:43.623]So again, a significant amount of biomass in that system.
- [00:34:48.240]And then if you look at the broad leaves,
- [00:34:50.700]broad leaf weeds in those system,
- [00:34:52.440]those cover crops did a great job
- [00:34:53.970]just because of that biomass.
- [00:34:55.290]They did suppress weeds.
- [00:34:57.780]This is the broad leaf weed.
- [00:34:58.740]You can see the lowest in these cover crops.
- [00:35:01.800]If you look at the total weeds,
- [00:35:03.540]again the same, brown top millet, buck wheat,
- [00:35:06.360]sorghum sudangrass, teff, they were the best cover crops
- [00:35:09.000]for summer for suppressing weeds.
- [00:35:10.983]And this is what the plot of sorghum sudangrass looked like,
- [00:35:15.106]four, five feet tall in about 45 to 50 days.
- [00:35:20.340]So a lot of biomass.
- [00:35:21.870]I tell that this is the place I want to be
- [00:35:25.080]when my wife is angry with me,
- [00:35:27.180]because she cannot find me if I get in there.
- [00:35:29.190]So it's pretty tall,
- [00:35:31.026]once you go in there you are lost.
- [00:35:32.310]So these are our quadrats for us to take the biomass.
- [00:35:35.506]But yeah, we are very impressed,
- [00:35:37.800]and we use sorghum sudangrass
- [00:35:40.890]on a very consistent basis at the farm now.
- [00:35:43.140]After any vegetable crop is done,
- [00:35:44.910]we try to put a sorghum sudangrass mix,
- [00:35:47.880]and sometimes we might add cowpea with it,
- [00:35:50.010]or sometime we add sun hemp with it.
- [00:35:52.740]Because sun hemp also grows tall,
- [00:35:54.930]and sorghum sudangrass is tall,
- [00:35:56.130]so they compete together really well.
- [00:35:57.780]If you grow cowpea with it, it just lingers at the bottom,
- [00:36:00.570]doesn't grow much biomass.
- [00:36:03.000]So it's not just research.
- [00:36:05.670]Research is valuable,
- [00:36:06.990]it's impactful when you see the adoption of that research.
- [00:36:10.380]So we have several growers we work with
- [00:36:12.660]and we are happy that they use some of the results
- [00:36:16.320]and cover crops we research on.
- [00:36:18.180]So this is Greg Reinhardt in Boone, Iowa.
- [00:36:20.940]Greg didn't use any cover crop,
- [00:36:23.040]and we introduced him to some of the brassica cover crops.
- [00:36:25.710]So this is yellow mustard, this is oil seed added,
- [00:36:28.403]there's a control plot,
- [00:36:29.490]and we showed some of the results
- [00:36:30.750]of what happens with weeds.
- [00:36:32.190]And so he now plants, every sweet corn plot
- [00:36:35.160]that is harvested in September,
- [00:36:38.460]after that will go in radish,
- [00:36:40.980]or a mix of oil seed radish,
- [00:36:45.162]and sometime he'll add the peas in it,
- [00:36:51.660]and sometime oats, three-way mix.
- [00:36:54.090]But he's expanded into cover cropping.
- [00:36:55.620]So it's good to see impact that growers are using it.
- [00:36:58.350]John Kroul, another great collaborator who works with us,
- [00:37:01.740]this is John's farm in Mount Warden, Iowa,
- [00:37:04.710]doesn't use much cover crop.
- [00:37:06.120]We went there, did some experiments, just on-farm trials.
- [00:37:08.910]These are not replicated trials.
- [00:37:10.779]Greg's was, but this was not.
- [00:37:12.870]And three big strips with different cover crops.
- [00:37:16.050]This is buckwheat.
- [00:37:17.370]We had, you can see buckwheat here,
- [00:37:19.530]we had oil seed radish also, and we had a control plot.
- [00:37:23.250]And so for the grower to see
- [00:37:24.480]what a control plot looks like in 45 to 50 days
- [00:37:27.720]and compare that with something like this,
- [00:37:30.240]then they see like, oh yeah, I think I'll grow this.
- [00:37:33.390]And it's easy to kill.
- [00:37:34.920]I can mow it, I can herbicide,
- [00:37:36.780]I mean with buckwheat sometimes you can just look at it
- [00:37:38.997]and it'll die.
- [00:37:40.645]It's very flimsy, especially 45, 50 days,
- [00:37:44.880]and you have to terminate it when it's at flowering,
- [00:37:47.640]because otherwise it'll go to seed,
- [00:37:49.590]and then it'll become a weed.
- [00:37:51.210]But it's very easy to kill.
- [00:37:53.220]So for John to see this
- [00:37:54.747]and look at the button weed, look at the lamb's quarters,
- [00:37:57.780]look at the red root pig weed.
- [00:37:59.580]It was a good way for us to show him, use cover crop,
- [00:38:02.550]especially for the summer period.
- [00:38:04.920]And add organic matter before your fall vegetable.
- [00:38:08.490]We do a lot of workshops in cover crop.
- [00:38:10.140]This is Dr. Tom Casper from the national lab
- [00:38:12.150]for Ag environment, USDA lab.
- [00:38:14.400]Tom has retired now, but a great collaborator,
- [00:38:16.890]and he helped us, me especially in the beginning,
- [00:38:20.255]to work on cover crops, look at options.
- [00:38:23.850]So great person to work with for cover crop.
- [00:38:27.030]We do a lot of field days with Amish and Mennonite growers,
- [00:38:30.179]other commercial growers.
- [00:38:32.250]Because we wanna make sure everybody gets a piece of the pie
- [00:38:34.620]and understands what the value of cover cropping is.
- [00:38:39.120]In the remaining 10 minutes,
- [00:38:40.380]I'm gonna go very quickly on some other research projects.
- [00:38:43.920]This is optimizing high tunnel tomato production,
- [00:38:47.070]and we use grafting.
- [00:38:48.300]In this case, this is a 30 by 96 high tunnel.
- [00:38:51.037]Kristine Lang, my grad student,
- [00:38:53.790]this is her project, she worked on it.
- [00:38:55.320]She's a faculty at South Dakota State University now.
- [00:38:58.230]Kristine came up with some good recommendations
- [00:39:01.140]in terms of grafting for commercial purposes,
- [00:39:04.110]for commercial growers.
- [00:39:05.610]So in high tunnels, the major challenge
- [00:39:07.800]is there's no rotation.
- [00:39:10.470]Year one, year two, year three, year four,
- [00:39:12.660]it's all tomatoes,
- [00:39:13.650]and it makes sense because that's the most profitable crop.
- [00:39:16.410]Why wouldn't a grower do that?
- [00:39:17.837]So we are not trying to eliminate rotation.
- [00:39:20.700]I think rotation is still critical,
- [00:39:22.620]but maybe grafting is another way
- [00:39:24.240]to look at managing diseases in the soil.
- [00:39:27.570]We did not have any disease, by the way,
- [00:39:29.040]in our high tunnels.
- [00:39:30.536]So we are not doing it to manage disease.
- [00:39:32.190]There was no disease, but we wanted to see
- [00:39:33.600]whether grafting is beneficial or not.
- [00:39:35.370]So we are using splice grafting.
- [00:39:37.500]These are 21 days, three weeks old seedlings or transplants
- [00:39:42.480]just cut into a splice.
- [00:39:44.250]You put this silicone base clip on top of it,
- [00:39:47.997]you get it from Johnny's.
- [00:39:49.770]This is the root stock.
- [00:39:51.180]You put the scion on top of it, you clip it together
- [00:39:53.970]and you put it in a healing chamber.
- [00:39:55.896]And in three to four weeks it'll heal.
- [00:39:58.080]The transplant is ready.
- [00:39:59.520]And then we compare different rootstocks.
- [00:40:01.940]In this trial we are looking at different rootstocks.
- [00:40:04.257]First one is the Scions, so that's the standard for all.
- [00:40:08.160]But these are the rootstock.
- [00:40:10.530]Some of the most common one, Arnold, Beaufort,
- [00:40:13.374]Estamino, Maxifort, they are more available.
- [00:40:16.440]You can see them out there.
- [00:40:17.400]So we wanted to compare those rootstocks
- [00:40:19.620]to the Scion of BHN 589,
- [00:40:21.540]which is a standard determinate tomato,
- [00:40:23.820]which many commercial growers grow.
- [00:40:27.139]There's some seeding dates out there,
- [00:40:29.400]this is how the high tunnel looked like
- [00:40:30.930]when we transplanted.
- [00:40:32.730]we are trellising them, staking them.
- [00:40:34.636]And then as the season progresses, we use switchgrass mulch.
- [00:40:39.300]And I highly recommend using that for weed suppression.
- [00:40:42.210]These tomatoes are still on black plastic mulch,
- [00:40:44.610]you can see that.
- [00:40:45.660]But between the beds here,
- [00:40:49.121]we use switchgrass mulch, about four inches,
- [00:40:50.790]four to five inches thickness.
- [00:40:52.770]Over the season we walk on it, students walk on it,
- [00:40:55.410]we are harvesting it, it'll go down,
- [00:40:57.420]but absolutely no weeds.
- [00:40:59.130]It does a great job to suppress weeds.
- [00:41:02.375]And I'll talk about that later.
- [00:41:05.430]So let's quickly look at some of the results here
- [00:41:07.457]of which rootstock should a grower use
- [00:41:10.860]if they want to go into grafting.
- [00:41:14.040]So first thing and what does that grafting do?
- [00:41:16.680]So we do see that the grafted rootstock,
- [00:41:20.970]so Arnold, Beaufort, DRO14, Estamino,
- [00:41:25.800]they definitely did better or higher
- [00:41:29.040]as compared to the non grafted, the self grafted,
- [00:41:32.490]so you cut the scion and you put it back on it.
- [00:41:34.650]So that's a positive, it's a control.
- [00:41:37.050]So we have non grafted, self grafted, and many other,
- [00:41:40.110]and so these rootstocks performed really well.
- [00:41:43.290]You can see the yields, the marketable fruit per plant
- [00:41:45.930]is higher in those rootstocks.
- [00:41:49.920]And overall you can get about 51 to 72% increase.
- [00:41:54.090]This is a non infested soil, no disease,
- [00:41:56.790]just the effect of grafting yield.
- [00:42:00.500]Again, you can see statistically difference.
- [00:42:04.770]These are higher.
- [00:42:06.423]So these rootstocks, so we recommend growers
- [00:42:08.190]using Arnold, or Beaufort, or Estamino,
- [00:42:10.830]because yes, you'll see a boost.
- [00:42:14.190]Again, 57 to 71% in terms of marketable yield.
- [00:42:19.620]Total fruit per plant, again, those rootstocks stand out.
- [00:42:24.630]So that's a good rootstock to use for commercial purposes.
- [00:42:28.830]So some key points, again highlighting those cultivars here,
- [00:42:32.940]we look at some of the rootstocks here
- [00:42:34.740]and some the seed costs.
- [00:42:36.780]It has gone up, this was several years back,
- [00:42:39.780]three or four years back.
- [00:42:41.310]Now these costs have gone up.
- [00:42:43.050]So like the Estamino was maybe 30 cents,
- [00:42:46.920]but now I think it's more than that,
- [00:42:48.180]maybe 75 cents to a dollar for a seed of that root stock.
- [00:42:52.380]So things are getting more expensive.
- [00:42:56.400]There are challenges also when you graft,
- [00:42:59.040]this is the same tunnel later in the season,
- [00:43:00.870]the plants grow so huge and big that we had to double stake.
- [00:43:05.850]So we had to tie another stake on top of this
- [00:43:08.700]to manage that foliage up there.
- [00:43:11.663]Ad I don't know Sam, if it has happened to you,
- [00:43:15.450]but has a row fallen sometime?
- [00:43:18.447]And it is so frustrating and difficult to pull that row up.
- [00:43:21.870]Many people have to stand
- [00:43:22.890]with their backs up and slowly put it up.
- [00:43:24.780]It's not easy.
- [00:43:26.326]So you don't want to have the tomato row fall over.
- [00:43:30.300]So we did, we had that.
- [00:43:33.120]But yeah, that is a challenge.
- [00:43:34.890]I want to highlight this here,
- [00:43:36.540]and maybe Joe will get a kick out of it
- [00:43:38.820]since he is an entomologist, this is sweet alyssum.
- [00:43:42.326]And sweet alyssum, we use it as a beneficial plant
- [00:43:45.960]to attract beneficials.
- [00:43:48.450]And whenever we had sweet alyssum,
- [00:43:50.070]we had a ton of power flies, lady bug beetles.
- [00:43:53.850]So now we have made it a standard practice
- [00:43:56.370]that wherever we have plots, especially vegetable plots,
- [00:43:59.040]we plant some sweet alyssum either on the edges
- [00:44:01.745]or on the ends.
- [00:44:03.660]And because we think that it definitely brings in
- [00:44:05.550]beneficial insects.
- [00:44:06.780]We didn't compare disease insect, we did not,
- [00:44:08.970]but having those insects there itself
- [00:44:11.760]was very reassuring.
- [00:44:13.380]We also tested borage, another crop.
- [00:44:16.800]We tested Xenia plant, and they do bring in,
- [00:44:20.550]but sweet alyssum the best
- [00:44:22.050]in terms of bringing more beneficial,
- [00:44:24.420]because it's a perpetually flowering plant.
- [00:44:27.120]It just keeps flowering year long.
- [00:44:29.220]So that's the benefit.
- [00:44:32.430]So I'm nearing the midlife crisis, right?
- [00:44:35.580]So many projects, so many things, so many things.
- [00:44:37.800]So then from a horticulturist, I turned to poultry.
- [00:44:42.540]And I don't know why I did that, but it just happened.
- [00:44:45.126]I think because of a lot of colleagues
- [00:44:47.370]in different universities, and in Iowa State,
- [00:44:49.410]we all got together and we discussed,
- [00:44:51.570]can we make our organic systems more robust?
- [00:44:55.110]Can we add animals to the system?
- [00:44:57.000]And again, I have no interest in poultry
- [00:44:59.520]and no expertise in poultry.
- [00:45:01.230]But Moriah, my grad student, she was into it.
- [00:45:03.540]She said, "No, we should do some poultry work.
- [00:45:05.400]Let's integrate poultry into vegetables."
- [00:45:08.130]So this could be my midlife crisis question here,
- [00:45:11.340]but what we are trying to do here
- [00:45:12.980]is to integrate vegetable and poultry production together.
- [00:45:16.590]There are big no-nos here.
- [00:45:18.450]Food safety is a big concern when you have poultry.
- [00:45:21.270]But we are not having poultry and vegetable
- [00:45:23.100]at the same time, we are looking at rotations.
- [00:45:26.280]So we developed, we wrote a proposal,
- [00:45:30.540]and we were funded by the OREI, NIFA OREI.
- [00:45:35.345]Iowa State, we were the lead, University of Kentucky
- [00:45:37.440]and UC Davis.
- [00:45:38.580]We all came together thanks to many of these collaborators
- [00:45:41.670]at different universities who made this project possible.
- [00:45:44.040]It's still going, this is the last year,
- [00:45:45.720]and we are wrapping up right now.
- [00:45:47.520]But what we were looking at is these three rotations
- [00:45:50.370]in an organic system.
- [00:45:51.818]You grow a spring vegetable, broccoli, for example,
- [00:45:55.710]or spinach, for example.
- [00:45:56.940]You harvest the vegetable,
- [00:45:59.010]and after that you introduce poultry
- [00:46:01.140]to eat whatever is left over.
- [00:46:03.990]So that's chicken.
- [00:46:05.280]And then once then the chickens are taken out,
- [00:46:07.380]they're slaughtered.
- [00:46:08.520]So that's a meat for another revenue stream for the grower.
- [00:46:11.740]These poultry, these are broiler.
- [00:46:14.250]And then you put a cover crop.
- [00:46:15.780]Versus you have vegetable,
- [00:46:18.015]then you put a cover crop, then you put a chicken,
- [00:46:19.890]and compare that to a treatment which never had an animal,
- [00:46:22.920]only vegetable and cover crop.
- [00:46:25.230]So that's the design.
- [00:46:27.150]We had different crops we are looking at.
- [00:46:28.500]We did change from spinach to broccoli,
- [00:46:30.840]because if you have harvested broccoli or grown broccoli,
- [00:46:33.420]once you harvest the head, there's a lot of biomass
- [00:46:36.150]left in the field.
- [00:46:37.230]So how can we use that biomass?
- [00:46:39.840]So this is Liz Bobbeck,
- [00:46:41.430]she's a poultry specialist at Iowa State.
- [00:46:44.760]So Liz was helpful in figuring all this out,
- [00:46:47.130]especially with the feed aspect of it.
- [00:46:49.380]So these are the chicken tractors which we built,
- [00:46:51.716]which can move, and many growers are interested.
- [00:46:54.750]Organic growers are really interested
- [00:46:56.070]about chicken tractors.
- [00:46:57.895]You can flip this, there's a lever here on the other side
- [00:47:01.950]and it comes up so you can easily push it
- [00:47:04.980]and then lay it down.
- [00:47:05.813]So every day these chicken tractors move
- [00:47:07.740]to a different area.
- [00:47:09.600]So just to give you an example, this is the second rotation.
- [00:47:11.760]This is cowpea and teff as a cover crop.
- [00:47:14.730]And we are moving this chicken tractor from here,
- [00:47:16.740]one day here, second day here, third day here,
- [00:47:19.440]fourth here, fifth here.
- [00:47:21.399]So we just keep moving.
- [00:47:22.232]So it'll move 45 times in 45 days,
- [00:47:25.350]and by that time the cover crop will be done
- [00:47:28.020]and the chickens will be ready to be slaughtered.
- [00:47:30.570]So these are the chickens in there.
- [00:47:32.550]So Liz was very interested in the behavior of these birds.
- [00:47:36.410]So what do they do?
- [00:47:37.560]So she compared some birds that were inside,
- [00:47:39.840]in the building versus outside.
- [00:47:41.850]And she painted some of these birds with different colors.
- [00:47:44.280]You can see that, some of the birds.
- [00:47:45.660]And they put a camera in there to look at what they do.
- [00:47:49.560]Do they forage more?
- [00:47:51.180]Do they sit in a corner?
- [00:47:52.800]And so she's analyzing this data right now,
- [00:47:54.630]but it was a cool video to see these birds out there
- [00:47:58.635]maybe going at insects, or larva, or a beetle,
- [00:48:03.180]and she compared that with the indoor birds
- [00:48:05.400]to see the behavior.
- [00:48:06.660]What's the change in behavior out there?
- [00:48:08.257]So this is to show you how we move this.
- [00:48:10.050]This is how we move first graze.
- [00:48:14.490]When you move one time, these birds are voracious eaters.
- [00:48:18.870]You can see the difference here versus here, right?
- [00:48:22.620]They were just completely decimated.
- [00:48:24.060]So we take it 15 times,
- [00:48:26.310]and then it goes to the start again, again 15 times.
- [00:48:28.590]And so that's how we get 45.
- [00:48:30.600]But we were impressed with the cover crop.
- [00:48:33.060]So this chicken tractor has gone through this until here
- [00:48:36.600]and then it goes back there.
- [00:48:38.370]But until then you can see there's some regrowth,
- [00:48:39.951]which was interesting to see that the cowpea came back.
- [00:48:43.287]And so, but after the second grazing, everything was done.
- [00:48:46.140]There was nothing left.
- [00:48:47.160]So there's some regrowth.
- [00:48:49.290]We have many colleagues there.
- [00:48:50.343]This is Dr. Angela Shaw.
- [00:48:52.094]She's at Texas Tech now looking at salmonella in the soil,
- [00:48:58.620]we did not find any.
- [00:48:59.580]There was one positive sample one of the years.
- [00:49:01.260]So that was promising that these systems
- [00:49:03.977]can be relatively free from salmonella
- [00:49:06.660]depending on the time of the year.
- [00:49:08.610]So we sampled many times
- [00:49:10.230]and we did not find any positive sample except one.
- [00:49:13.200]We have Jim Dickson, and so he taught me
- [00:49:15.540]how to do the boot swab analysis.
- [00:49:17.220]So I was like, Dr. Dixon, what is boot swab analysis?
- [00:49:20.453]And he pats me on my back and he says,
- [00:49:22.177]"It's not fancy at all.
- [00:49:23.370]It's a boot with a swab."
- [00:49:25.110]And you just walk, you can see that,
- [00:49:27.330]there's a swab on his boot here.
- [00:49:29.940]And then he will take that swab to his lab
- [00:49:31.890]and they will analyze for pathogens in there.
- [00:49:34.350]So Jim has been a great collaborator,
- [00:49:36.900]and for me to learn about some of these pathogens.
- [00:49:41.220]Okay, we do see that there's benefits
- [00:49:43.470]of some of the results from this study.
- [00:49:44.910]We do see that the rotation systems, R1, R2, and R3,
- [00:49:49.800]this is the only vegetable, this is the rotation one.
- [00:49:53.070]We see that overall 30% higher nitrates.
- [00:49:56.580]And that's because of the poultry manure
- [00:49:58.560]that is spread there.
- [00:49:59.790]Now it is given we know that.
- [00:50:01.620]But what is the benefit?
- [00:50:02.880]The benefit is that the next year
- [00:50:04.140]the grower doesn't have to bring off farm input.
- [00:50:07.710]You can put less fertilizer in there
- [00:50:09.900]because the poultry has already fertilized that,
- [00:50:12.150]and they got some additional revenue by selling the birds.
- [00:50:15.330]And you have organic systems that talk about rotations,
- [00:50:18.210]which are comprehensive, incorporation of animals and crops.
- [00:50:22.670]So we are trying to demonstrate that this could be done.
- [00:50:26.790]And finally, and I'll stop after this.
- [00:50:28.969]There's no results on this.
- [00:50:31.140]This project just got started.
- [00:50:33.510]This is a Department of Energy funded project.
- [00:50:36.120]Again, we are lucky to have collaborators
- [00:50:38.460]in different departments here.
- [00:50:40.137]I was fortunate to lead this team
- [00:50:42.078]from Matt O'Neil from Entomology,
- [00:50:45.510]Anne Kimber engineers, electrical computer engineering,
- [00:50:48.690]economics, Hongli, and so many departments.
- [00:50:51.060]We all got together and aligned,
- [00:50:53.460]energy was going to install a solar farm
- [00:50:58.050]at the ISU campus.
- [00:51:01.890]And so we asked them, hey, can we use that land
- [00:51:04.680]to do some research looking at some agrivoltaic type work
- [00:51:07.380]where we can grow some crops here
- [00:51:10.080]and look at the effect of those crops
- [00:51:12.180]and look at whether that affects your panels?
- [00:51:14.430]And they were willing to do that.
- [00:51:16.050]So we collaborated, submitted the grant.
- [00:51:18.030]DOE was interested to fund it.
- [00:51:19.774]We submitted the proposal and it got funded.
- [00:51:22.894]And so this is something new
- [00:51:24.660]that is happening in the lab starting this year.
- [00:51:27.300]And things that we are going to focus on,
- [00:51:29.580]this is agrivoltaic, that's what the name is,
- [00:51:33.720]agriculture and solar panels together.
- [00:51:36.180]So we are focusing on habitat conservation.
- [00:51:38.700]So Matt O'Neil is going to look
- [00:51:39.930]at different pollinator mixes and what is the benefit
- [00:51:44.010]of that pollinator mix there and the insects,
- [00:51:46.494]beneficial insects.
- [00:51:48.450]Economics, of course it has to pan out
- [00:51:50.580]in terms of yield from these crops in shade.
- [00:51:53.640]How will they grow?
- [00:51:54.675]We have different configuration of panels.
- [00:51:56.974]The one I showed you is the fixed panel.
- [00:51:59.790]We have single access tracker panels that move with the sun.
- [00:52:02.880]So we have some crops in there.
- [00:52:05.134]We are looking at five crops, from broccoli, squash,
- [00:52:09.330]pepper, raspberries, and strawberries.
- [00:52:12.330]So those are the crops we are focusing on.
- [00:52:13.800]So many, many people team,
- [00:52:15.240]I'm just representing the team.
- [00:52:17.940]It's a big team effort on this grant.
- [00:52:21.570]Reducing crop stress with these panels,
- [00:52:23.640]maybe energy production.
- [00:52:24.690]They're looking at what the panels will do
- [00:52:26.370]depending on what crop is underneath them.
- [00:52:29.310]And of course soil conservation,
- [00:52:31.140]because there is a possibility, we now have big rain events.
- [00:52:35.014]All the rain will hit the panel, fall on the ground,
- [00:52:38.100]and there could be a big erosion event.
- [00:52:39.750]It can take a lot of soil out.
- [00:52:41.490]So will these pollinator mixes help to reduce that erosion?
- [00:52:45.750]So this is a new project.
- [00:52:46.800]We are all excited.
- [00:52:47.633]We planted our raspberries last fall.
- [00:52:49.710]The broccolis just got seeded in the greenhouse
- [00:52:53.340]early this week, and we'll transplant them
- [00:52:55.380]in middle of April.
- [00:52:56.700]So the project will soon kick off.
- [00:52:59.760]So of course I showed you a lot of things,
- [00:53:01.920]a lot of projects, lot of things that are happening.
- [00:53:04.200]It won't be possible without graduate students.
- [00:53:06.990]So a big thank you to all the graduate students.
- [00:53:09.534]They do a great job in the lab, in the field.
- [00:53:13.920]This is by the way the cabbage plot where we harvested.
- [00:53:16.770]And then students, you know, they are students
- [00:53:19.710]and I like to be with them.
- [00:53:21.330]So they said, "Hey, let's have a competition
- [00:53:23.610]of putting the cabbage on heads
- [00:53:25.890]and let's see who keeps the cabbage on
- [00:53:27.747]for the longest amount of time.
- [00:53:29.520]And whoever drops it first will take the picture."
- [00:53:33.510]So you can see who's missing.
- [00:53:35.940]I lost very quickly.
- [00:53:37.530]So I lost, so I had to take this picture
- [00:53:39.810]and in this case, I mean dedicated, right?
- [00:53:42.870]That cabbage, he's not gonna drop that cabbage.
- [00:53:46.050]So with that, again, thanks to all the grad students
- [00:53:48.720]and undergraduates who work in the lab
- [00:53:50.460]and make these projects possible.
- [00:53:52.874]Our partners, Iowa Specialty Crop Growers Association,
- [00:53:56.490]practical Farmers of Iowa, the Department of Ag,
- [00:53:59.460]NIFA, SARE, Leopold Center,
- [00:54:02.475]everybody has to pitch in,
- [00:54:04.590]and so without that it won't be possible.
- [00:54:06.300]So big thank you to all of them
- [00:54:10.230]that helped towards funding these projects.
- [00:54:12.600]So this is my email, this is my lab website or webpage.
- [00:54:16.830]We post a lot of funny videos, and good videos,
- [00:54:20.100]and reasonable videos, and research reports
- [00:54:23.580]so growers can go and download events.
- [00:54:27.210]So if you wanna look at some other things in detail,
- [00:54:31.020]please feel free to visit the lab.
- [00:54:32.970]And so with that, I will stop
- [00:54:35.130]and I'm happy to answer questions.
- [00:54:37.350]All alright.
- [00:54:38.659]When you showed your conventional tillage vegetable control
- [00:54:44.675]it doesn't sync with what I was used to.
- [00:54:47.430]So I wanted to ask you about Iowa vegetable growing.
- [00:54:51.300]Usually we used a raised bed and you could shape
- [00:54:55.620]or aim the bed toward the early sun
- [00:54:57.900]if you wanted a warmer soil temperature.
- [00:55:00.450]So some things like you could get a melon crop
- [00:55:03.570]with a short day length in as a crop
- [00:55:07.800]in some states like Iowa where, without shaping the bed
- [00:55:12.000]and aiming it toward the sun, you couldn't do that.
- [00:55:14.550]But what I see, your system,
- [00:55:16.140]it actually looks like you have greater density of planting.
- [00:55:22.650]So that looks like a big benefit.
- [00:55:24.755]But then again, you have no control of water movement.
- [00:55:30.030]So I think your soil would be all saturated
- [00:55:32.370]in the conventional system you show that was flat.
- [00:55:35.730]Yeah.
- [00:55:37.059]So I noticed sprinkler irrigation
- [00:55:39.210]instead of row irrigation.
- [00:55:40.980]They would've used row with the bed system,
- [00:55:43.620]but then the tractors have to have the wheels
- [00:55:46.050]spaced differently, the heights of the tractors
- [00:55:48.690]have to be different.
- [00:55:50.010]There's all these mechanical differences
- [00:55:52.614]a farmer would have to put up.
- [00:55:55.170]So did they already have a bed system
- [00:55:57.278]and they're now going to cover crop,
- [00:56:00.537]or is your control not quite what they had before?
- [00:56:05.670]Things like that.
- [00:56:06.503]So you're bringing a valid question here.
- [00:56:08.419]In reduced till system, I'll address one by one.
- [00:56:10.800]The first thing is the challenge for summer crops
- [00:56:14.340]because earliness is something which market values
- [00:56:17.130]and the growers want to grow it early,
- [00:56:18.690]especially summer squash and musk melons.
- [00:56:21.600]So such systems are not much suitable
- [00:56:24.180]for cucurbit crops that you need earliness.
- [00:56:26.610]The second about using the raised bed,
- [00:56:28.654]we could have used the raised bed,
- [00:56:30.780]but we erred toward not using it
- [00:56:33.030]and keeping the cover crops constant.
- [00:56:34.800]So for example, a commercial grower
- [00:56:36.420]might not even have a cover crop.
- [00:56:39.690]But in our case we kept the cover crop.
- [00:56:41.760]The cereal rice still grew there four or five feet.
- [00:56:44.910]We flail mow it and then we tilled it in the soil.
- [00:56:48.120]But for that we had to wait
- [00:56:50.457]until whenever other treatments were ready.
- [00:56:52.158]So we erred more towards taking care
- [00:56:53.280]making cover crop being part of it.
- [00:56:55.110]If it was a conventional grower,
- [00:56:56.340]and many conventional grower do that,
- [00:56:57.960]is they would not have a cover crop in May.
- [00:57:00.990]They will till, they'll create raised bed
- [00:57:03.210]with black plastic mulch and drip tape.
- [00:57:05.310]We had drip tape in this, but not black plastic mulch.
- [00:57:07.470]So we had to take a stand of which way we want to go.
- [00:57:10.890]So we thought, okay, let's just let the cover crop grow
- [00:57:13.230]as long as it could until May and we'll flail mow.
- [00:57:16.980]We tilled it under, we had to wait still
- [00:57:19.380]because this was significant amount of biomass.
- [00:57:21.480]And with rye you always have that planned back period
- [00:57:24.480]because of the allopathy issue also.
- [00:57:26.280]So we decided, okay,
- [00:57:27.838]we talked to some of the organic growers and they said,
- [00:57:30.697]"Oh, we don't use plastic much, we just use bare ground."
- [00:57:32.480]So we said, okay, so let's just compare bare ground.
- [00:57:34.800]And if we use plastic
- [00:57:37.140]and compare that with conservation tillage
- [00:57:38.790]or reduced tillage, the plastic will always be higher,
- [00:57:41.010]I mean ahead, because of that temperature,
- [00:57:43.470]because of that moisture and the good till.
- [00:57:45.690]So we want to put the reduced tillage
- [00:57:47.340]on equal parity with other treatments.
- [00:57:49.500]That's why we did that.
- [00:57:53.220]But we did wrestle with that question,
- [00:57:54.810]black plastic mulch or bare ground.
- [00:58:07.392]We have one question is,
- [00:58:08.580]what experience do you have in organic no-till
- [00:58:11.940]and do you have any recommendation?
- [00:58:13.875]Just to follow up with that one,
- [00:58:15.910]why do we continue to pursue monoculture
- [00:58:18.840]for vegetable production?
- [00:58:21.510]There are many advantages to intercropping systems,
- [00:58:25.170]but people usually cite labor increase as a deterrent.
- [00:58:29.580]What's your opinion?
- [00:58:30.570]Sure, so the first question with no-till
- [00:58:33.592]in organic systems, I primarily focus on strip-till,
- [00:58:37.440]we have an organic specialist in our department,
- [00:58:39.510]Dr. Kathleen Dellit.
- [00:58:40.770]So Kathleen does a lot of no-till work.
- [00:58:43.140]So we primarily look at strip-till
- [00:58:45.270]because we think in the Iowa growing condition,
- [00:58:47.550]because it's cold in the spring and we want early start,
- [00:58:51.000]we absolutely need that strip-till
- [00:58:53.310]just to break that soil and make that transplanting easy.
- [00:58:55.830]So we stick with that.
- [00:58:57.600]The second question about diversity,
- [00:58:59.854]I'm a big proponent of that.
- [00:59:02.460]In this research project, the main goal
- [00:59:05.130]was to look at, many projects we are focusing
- [00:59:08.220]on a specific treatment.
- [00:59:09.660]Diversity is not.
- [00:59:10.770]But from a PhD work, that was one of the questions.
- [00:59:13.410]And we did find that if we have a monoculture of cucumber
- [00:59:18.873]and we compared that with, not a polyculture,
- [00:59:23.550]but a biculture with tomatoes.
- [00:59:25.950]So think about eight rows of cucumber
- [00:59:28.770]versus four rows of cucumber,
- [00:59:30.570]but they're cucumber, tomato, cucumber, tomato,
- [00:59:32.520]cucumber, tomato.
- [00:59:33.750]And we did that and we found that the attack
- [00:59:38.130]of the cucumber beetles on the cucumber,
- [00:59:40.940]when you do look at the severity
- [00:59:41.970]and on number of plants dying because of bacterial wilt,
- [00:59:44.880]Erwinia tracheiphila,
- [00:59:46.199]we found that there was significant differences
- [00:59:48.570]in that the biculture,
- [00:59:50.817]where tomato and cucumber were there,
- [00:59:53.010]they were declining on a very slower rate
- [00:59:55.530]as compared to the monoculture.
- [00:59:57.240]So absolutely yes, we would love
- [01:00:00.150]to do polyculture, biculture.
- [01:00:02.430]And if it fits the system, in our case it was raised bed,
- [01:00:05.260]six feet centers with drip tape so it was easy to manage.
- [01:00:10.260]So if we grow things, it's better to grow
- [01:00:13.675]different crops in different beds.
- [01:00:16.140]Of course it has to fit the demand for that crop.
- [01:00:19.260]Farmers sometimes have to meet a demand,
- [01:00:20.910]and they need this much so they focus that way.
- [01:00:22.770]But diversity always helps.
- [01:00:24.210]But again, thinking about pollinators,
- [01:00:26.295]that is another way to make sure there's even pollination
- [01:00:30.090]and creating that diverse cropping system.
- [01:00:41.190]Nice talk Ajay.
- [01:00:42.240]So of course I need to ask an insect question.
- [01:00:45.217]So you showed that clover study
- [01:00:47.580]with the rhizobium inoculation and without rhizobia.
- [01:00:51.330]So is that affect any insect population
- [01:00:54.300]or insect community on those clover?
- [01:00:56.760]Yeah, that's a good question.
- [01:00:57.930]And yeah, we did not collect any data
- [01:00:59.913]on the insect side of things.
- [01:01:02.430]We primarily just replicated inoculated, non inoculated,
- [01:01:07.170]seeded.
- [01:01:08.003]We watered it to establish.
- [01:01:09.900]But after that we just walked back
- [01:01:11.940]and we did not even weed, we just weeded
- [01:01:13.950]at the end of the season
- [01:01:14.910]to see which one is more suppressive to weed.
- [01:01:16.950]So I cannot say what was the insect population in those,
- [01:01:21.457]but we definitely saw the benefit of using the rhizobium.
- [01:01:24.720]And our system was focusing more
- [01:01:26.730]on whether there is difference,
- [01:01:28.650]because a grower might not grow the cover crop
- [01:01:30.870]for the entire season.
- [01:01:31.830]They will have a vegetable crop somewhere,
- [01:01:34.020]or if it's a fallow land instead of fallow,
- [01:01:35.820]they can use cover crop.
- [01:01:37.696]So I don't have information on the insect.
- [01:01:47.490]Any other questions?
- [01:01:54.060]Thank you very much, sir.
- [01:01:55.383]Thank you so much. (audience applauds)
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