(upbeat lively music) - Hello and welcome to Farm Connections.

I'm your host, Dan Hoffman.

On today's program, we visit Rockdale Quarry to learn about agricultural lime spreading.

Extension Specialist Vasu Sharma joins us to discuss irrigation practices in Minnesota and the University of Minnesota Extension brings us a new Best Practices segment all today on Farm Connections.

(upbeat folk music) - [Narrator] Welcome to Farm Connections with your host Dan Hoffman.

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You can call them for a quote today.

- Welcome to Farm Connections.

We're at Rockdale at the Rockdale Quarry.

And with me is Danielle Anderson.

Welcome to Farm Connections.

- Thank you.

- This is an amazing site.

We've got motion, nature, limestone.

What do you do here?

- Well, you could call me a heavy machine operator, laborer, run payloader, excavator, dozer, heavy machinery basically, so.

- Well, it's an amazing site.

Why do we need quarries?

- Well, there's lots of reasons.

We help bring rock to schools, get a good foundation to build a new school on, help for education.

Build airports, help with airports if they need a new runway.

Helping bring rock in for set up a good foundation for housing developments.

We also use it in the farm aspect.

We use the ag lime to put on fields, help crop production, which then in turn puts more food on the table for our consumers which is people like us.

- Well, let's talk a little more about that agricultural piece.

You amend the soils.

Why do we need to do that?

- So when we put lime on, it causes the pH to rise, which then lowers the acidity in our soils.

Farmers find that out by taking a sample and people do a test on it.

By doing that, we can really get a nice healthy plant which grows bigger, stronger, and then that in terms gets a bigger profit for farmers, which then also means more food on the table for us in your local grocery stores, farmer's market.

It just gives more food production to the world basically for people.

- Land is an important resource that's very expensive right now, so farmers want to get the most out of each acre likely, right?

- Correct.

- So when this limestone is applied to the fields, what time of year is that usually done?

- Fall.

So right now, we're getting pretty wrapped up with summer and crops are gonna start getting taken out of the field here pretty soon.

You can see beans are already starting to turn.

So as soon as the crops are out, farmers are spreading that lime down before they go in and till it up for the winter.

- It seems like especially soybeans and alfalfa or legumes respond to a pH that's neutral.

- Yep, absolutely.

Helps bring in a lot of calcium too to that ground.

It's amazing what the minerals from the lime, the crushed rock which is underneath the soil, when you bring that back up and you put it on the field, it's amazing how well that can give nutrients to that soil base.

- Well, an acid soil doesn't even smell that great, right?

- No, not at all.

- So perhaps you're a soil sweetener.

- Basically.

You could call me that, I guess.

- As you raise the pH and you move towards more alkalinity, crops do better, of course, unless you get too alkaline, that's almost impossible in our trade area, right?

- Right, right, yeah.

And it's amazing.

It's not used as much as it should be.

There's a lot of farmers out there that don't realize how much this lime, putting it on your field can help them so much just make a healthier plant, the profit in the long run.

I would say a third of the farmers really should be using it a lot more than they normally do.

- I certainly remember my dad and uncle respecting the need for limestone to neutralize that soil.

- Yep.

- Everything seemed to work better.

The plant utilized nutrients better and was more efficient.

- Yeah.

- And the crop was better.

- Right, exactly.

It helps more than just the farmers, putting a profit to them.

It's helping us consumers in the long run.

If they can produce more for us, we have more to eat.

So that's the biggest thing in return for us.

- Well, as farmers go, they're scientists and you mentioned soil tests.

- [Danielle] Yep.

- Do you get to soil tests or do the farmers give it to their agronomists and then order the product from you?

- Yep, the farmers give it to their agronomists.

We don't do anything with that.

We just supply the lime.

They can base it off of, oh, they need two ton per acre of lime or three tons.

Three tons is probably average just depending on how much lime they need per acre on their field to adjustify and move those pH levels.

- How often on average would you say a farmer needs to reapply your product or limestone?

- It depends on the field.

Sometimes it's every three years.

It can be every five.

Some do it every year.

Depends on are they running in a sandier environment?

Are they running in big, black, thick dirt that's good for farming?

It just really depends on what type of soil they're working with and what their tests come back with and what their agronomists say basically.

- Well, you mentioned roads.

Certainly, many of our roads in Southern Minnesota and across this part of the Midwest are covered with limestone, right?

- [Danielle] Absolutely.

- So if you do a soil test, it's interesting, but the first 100 feet in the field gets the dust or the limestone off the field.

So oftentimes, you don't have to put as much on, right, close to the road.

- Yep, yep.

And we do that.

A lot of rock comes out here and we put 'em on all the township roads.

We spread, oh, as soon as road restriction comes off, we're out there spreading rock on these roads.

And like you said, it's dusty.

And when it happens, yeah, that dust floats, it carries, and it does no harm for the crops.

- [Dan] It actually improves the first few feet, right?

- Correct, yep.

- So they possibly could buy less later from you for that first 100 feet or so.

- Yep, in theory, yep.

- What other places besides agriculture do your products go?

- So, like I mentioned earlier, we had a big job.

We were making a school in Kasson, Minnesota.

Very familiar probably with that area, building the base foundation of it to build the school on, parking lots for your schools, runways for your airports.

We're working on a job right now with that.

All that rock we specially make from this limestone.

Housing developments.

Every road that they drive on.

There's plenty, plenty, plenty and plethora of things that it's used for.

People come out and they get some rock for their cow yards, or they need to grab something for landscaping around their house, or we have plenty and plenty and almost anything you can find.

People come and buy boulders for their landscaping and we put rock everywhere.

Everyone needs rock.

Just simple things on your own driveway that you wouldn't think.

Filling in a pothole.

Little things like that, that's where it comes from is this quarry.

- Well, I, like you, like green grass and wonderful black deep top soil.

- [Danielle] Yep.

- But why is that not good for a road or a foundation of a building?

- That gets wet, it sinks, it's very mushy.

It's not as firm.

And this rock, it'll come in and really firm that up and get a really strong base.

And it'll be like driving on cement without actually having to make cement.

We run cattle and in our farm yard, we use what's called three eights minus.

And that's a type of product that we come and make from limestone.

And we can pack that in and it's so good on the cows' feet, it's so comfortable, it packs in and it's super, super nice.

Doesn't create mud.

It keeps the cows clean.

A lot of farmers come in and get it from here.

A lot of people use it just in their every day if they need a fill-in at their house.

It just keeps it really nice and everything clean and packed in really tight.

- Well, anybody that's walked or driven through mud appreciates what you just said.

- Right?

Exactly.

No one likes to walk in mud, have their boots get stuck, their shoes get dirty.

This rock, it's amazing what it can do.

You pack it in there and it really firms everything up and tries to take away that mud aspect.

- And in back of us in the far distance, there's some excavation taking the outcrop off.

Can you tell us about the procedure?

So once upon a time, this was flat land with perhaps some crops on top or maybe native grasses or trees.

What happened next?

- So when we come into mine this out, as you can see in the background, we take off that soil, we take that off.

People can use it for fill.

They come in, they use it for fill for putting a base down.

If they have an uneven where they're gonna put a shop, they'll go level it out with fill before they put the rock on top to really get that good structure.

So what we do is we take the soil off, we crop farm all around it, and then every year, we pull that soil off and that helps then get down and expose that rock.

And it's a lot easier for when our drillers come and our dynamiters come.

They don't have to fight through that dirt.

They can go straight to that rock.

So yeah, all this dirt that we pull off on the top, we do then in turn, we can sell that as black dirt if we get good black dirt, which helps in people's composts, if they need it in their garden, whatever.

They can come and buy black dirt or we can use it as fill too.

Depends on, basically trying to use every piece of environment and product that we get out of this company to give back to whatever the consumers want and use it in multiple different aspects, not just one specific thing.

- Well, as you pull the outcropping back and strip it back, below, you've got the sub soil or the bedrock rather.

You pull the sub soil off, you've got the bedrock called limestone.

Now, what do you do with it?

It's just sitting there.

How do you bring value to that quarry, to that limestone?

- Yep.

So I'm assuming you're talking about how like we dynamite and we drill?

Yep, so we hire a private contractor in.

They drill down.

It's amazing how they do this.

They look at the profile of the rock, they decide how deep they're gonna go to make it smooth on the floor that we've already started from previous.

We load it up with dynamite, which is actually not dynamite sticks like some people might think.

It's actually a type of fertilizer that's used in the dynamite.

They send that down.

It's on an electrical charge.

There's a couple different companies that come.

They do it a little different, each one.

And it's really important when they're here that we shut the quarry down.

Safety's huge when they're here.

No one can be in the pit.

Everyone has to be accounted for.

There's only the one main guy that can send the charge off.

They dynamite, they blast.

Rock spreads out.

It's fabulous.

It's super cool to watch.

It's can be loud, can vibrates the ground.

It's really cool to be a part of.

Then, we set up a crusher plant.

We run this rock through and it pretty much breaks it down.

And then we screen out the lime.

So the lime's like super, super thin, dusty.

No rock really.

It's very a fine material.

And every time one bucket of rock comes in, we're making lime left and right.

It's coming out.

And it's basically a byproduct of like our road rock, the things that go to make your roads for your townships, and going to your schools, and all the things we talked about earlier.

Lime is our byproduct, you know?

So we're, like I said earlier, we're trying to make every ounce of product that comes out of here is getting used for something beneficial that's needed outside of this quarry.

- Well, thanks again for what you do for agriculture, making our crops better.

And also, all the materials you provide for construction.

Farmers build a lot of buildings.

- Yep, absolutely.

It's like I said, this rock goes to everywhere.

People wouldn't imagine where this rock is being used.

It's right there, right in their back doors that they wouldn't really recognize.

- Danielle, thanks for sharing your story and the story of your family quarry.

It's super interesting.

- Thank you very much.

We really appreciate your time.

- Stay tuned for more on Farm Connections.

- [Narrator] Farm Connections Best Practices brought to you by.

- My name's Daniel Kaiser, Extension Nutrient Management Specialist with the University of Minnesota.

And this is today's Best Practices segment.

For today's segment, what we're gonna talk about is making nutrient management decisions.

With the uncertainty in prices both from the fertilizer side and the crop side, there's been many questions from growers on how to best manage your nutrients to try to make sure you're getting the most out of your overall investment.

Within the University of Minnesota research, we've been extensively looking at different things to try to fine tune where and when certain nutrients are needed.

Two nutrients that we've been putting a lot of emphasis on have been phosphorous and potassium.

And these are nutrients that are easy to determine where you need them based on a soil test.

So we get into years with a lot of uncertainty on prices.

If you have a soil test, that can go a long ways in determining where and how much of a nutrient that might be needed.

Phosphorus, for example, one of the things that we've been really looking at a lot of our research has been to focus it on looking at a risk assessment of what would happen if I didn't apply phosphorus.

And if we look at situations where we get into a very high soil tests or a Bray soil test of 20 or above, or an Olsen of 15 or above, we know that there's a very low probability at that point in time that the phosphorus that we're applying with fertilizer is actually going to be needed by the crop.

So it's one of the things to watch out for is that a lot of growers put a large emphasis on phosphorus when it comes to nutrients, particularly for corn production, that if you have a soil test indicating that you should have sufficient levels in the soil itself, that you shouldn't be too concerned about applying a low to no application in some of those fields.

And you should still have a high chance of getting maximum yield potential.

One of the things with potassium on the other hand is that we start looking at that is that while we can use the soil test for assessing where it's needed is that a lot of times, growers seem to prioritize it lower than phosphorus.

And many times, I think that's a mistake looking at a lot of our data with situations particularly in dry years where we see a stronger response to that particular nutrient.

So it's one of the things if you're looking at trying to assess what nutrients you need, particularly for corn production, we know that nitrogen is gonna be number one because we know that we get a large response to that.

Then, use your soil test for phosphorous and potassium.

Prioritize those based on what your soil test is.

And then we look at other nutrients like sulfur and zinc, zinc being one we can use a soil test as well to see where it's needed, being some things that we wanna start thinking about depending on certain circumstances within the soil.

So again, prioritize what you need, look at where you might be able to cut to make sure you're getting the maximum out of your investment.

So again, this has been Daniel Kaiser with today's Best Practices segment.

Thank you for watching.

- Welcome to Farm Connections.

Today, we wanna learn more about nitrogen and irrigation.

And to help us do that is Dr. Vasu Sharma from the University of Minnesota Extension.

Welcome.

- Thanks, Dan.

Glad to be here.

- Dr. Sharma, can you tell us a little bit about your work?

- Yes.

So today, we are here at Rochester, as you said, for the AFREC meeting.

And this project that I'm working on in Sand Plain Research Farm at Becker and at Westport location in Pope County is looking at interaction of irrigation with nitrogen, so how these two very important inputs to corn production impacts corn yield, and at the same time, environmental impacts like nitrate leaching, which is the main concern in Central Sands region of the state.

So this study is funded from AFREC for three years.

This is the last year of the study.

We started in 2020.

And yeah, we are looking at all these irrigation and nitrogen variables, and looking at how it impacts different crop parameters.

- Well, some of your charts were extremely interesting.

Well, actually, they all were, but one stuck out.

There was one year out of the three where the yield really dropped.

What happened?

- Yeah.

So actually, we have two years of data so far, 2020 and 2021.

And as you remember, 2021 was the drought year, really dry.

In that year, the yield was, in rain fed plots when we do not irrigate.

So one of the irrigation treatments is no irrigation.

So at these sandy soils like Becker and Westport, when we don't irrigate in those dry areas, we get no yield.

So zero yield, literally, like from all the replications at Becker.

- Who benefits most from your research?

- I think both irrigators, the growers who are irrigating, and also the government agencies who are making these policies would be benefiting from this data that we are collecting to look at how corn responds to different irrigation or water rates and nitrogen rates to get that optimum irrigation and nitrogen so that they can make policies.

And for growers as well, if they are looking for something, they are looking at changing their irrigation management, this data will give them confidence of knowing like if I change from this to this, how much yield reduction, which is the most important component when you're farming, like how much losses or how much gains I'm getting.

So if we provide this data to them, which they cannot do on their production farms.

One of my treatments is 350 pounds of nitrogen per acre, which you don't do that in production farm.

So we are the ones here at the university who do this kind of research where we can apply from zero to 350 pounds of nitrogen and tell them like, this happens to crop yield from all these rates.

- And of course, the government policies are sensitive to the environment as well as our farmers, but our farmers also have to look at profitability.

- Exactly, yeah.

So that's what I'm saying.

So if they are changing their management practice, this kind of data will give them confidence because we are giving them a range of different management practices and different nitrogen rates, both irrigation and nitrogen rates, so that they can decide on their own like what is best in terms of profitability, in terms of environment stewardship, what they want and how they want to decide.

- Potassium and phosphorus don't move as much in the soil water profile, but nitrogen certainly does.

And that's one of the reasons you're doing the research.

- Yes, phosphorus does too, but this project focuses more on nitrogen.

- Why is it significant if water and nitrogen move in our soils?

- So when we are talking about irrigation, most of the irrigation in Minnesota happens in the Central Sands region.

So when I say sands, that means these soils are very coarse texture.

So that means they cannot hold much water for a longer period of time.

So even if precipitation or rain happens, all that water, it tends to leach below the root zone.

So the root zone is where our roots are for the corn or any other crop.

The water goes down below that root zone that is not used by crop.

So it eventually going to the groundwater.

So now in the agricultural systems, we apply different fertilizers, right?

So some of those like nitrogen, it's very mobile.

So nitrate is very mobile in the root zone.

So when you have more water, then your crop can uptake.

That nitrogen along with that water is going to go in the ground water and eventually coming in the drinking water or nearby streams because all of this is interconnected below that surface.

So that's the main issue or we can say a problem that we are facing here in the Minnesota Central Sands, that nitric leaching is increasing in these agricultural systems.

And it's not just irrigation.

With precipitation, like 2019 was very heavy precipitation year.

So if we can manage somehow our agricultural practices like irrigation efficiently, I'm not saying we shouldn't put water.

Because we saw in our research that if we don't put water, what happens.

We decrease our yields, there's no yield.

So I would say in Central Sands, without irrigation, crop production is almost not feasible.

So we still have to do irrigation, but we have to do it efficiently.

And that's where these research results comes in to tell us like what is that efficient irrigation or best irrigation management practice.

- Well, you have a challenging job.

Not only do we have harsh climate in the winter, we can't get below the soil without some special equipment to monitor what's happening.

What equipment do you use?

- So during the growing season, for soil moisture, like to understand the soil water dynamics under these different irrigation treatments, we have soil moisture sensors that tells us that volumetric water content and how much water is in the soil profile.

And we continuously measure that throughout the growing season, starting from planting to harvest.

For nitrates, we install lysimeters and specifically suction cup lysimeters.

So it's a porous cup that we install at four feet, around three and a half to four feet depth, which is below the corn root zone to collect the water samples of any water that's coming below that corn root zone which is not used by the crop.

We collect that sample and then send it to lab to understand how much nitrate is in that water sample.

So when we know that under each of these irrigation and nitrogen treatments, we know that how much we are leaching and how much is going to the groundwater.

So those are the two main equipment as what I say, soil moisture sensors and suction cup lysimeters that we are using in this research.

- Will that give real time data?

- That gives real time data.

So we collect it every week throughout the growing season, sometimes twice a week.

- So when the rainfall changes or irrigation changes, you're probably seeing some spikes in activity?

- Yes.

So with irrigation or rainfall, we do see a spike in the water that is going in those lysimeters below the root zone.

And again, a higher nitrate load or nitrate leaching.

- You mentioned putting the instruments about four feet below the surface to get a test on what's happening and what's moving through the soil profile.

Does that disturb the soil and does it take a while for that soil to get back into what I'd call normal conditions?

- That's a great question.

So that was the one reason that we wanted to install these lysimeters permanently because each year when you install them and reinstall them, you disturb that soil.

And there is that disturbance that creates the nuisance, you know?

So you see that variability in the data.

So that's why for this research, we installed permanently 192 lysimeters at Becker in around six acres area.

And at Westport in Pope County, we also installed 192 lysimeters in 13 acres area.

And these are permanent.

So the first year data would be, because of the disturbance of the soil, I would say there might be some variability, but after one year, there's more stability in the data.

- Very interesting.

And finally to wrap up, advice for perhaps young students thinking about research or education beyond high school.

- I think University of Minnesota have great opportunities for after high school, even after the undergrads.

So for myself, this project that we are talking about today, we have two students, one undergrad student and one graduate student.

She's completing her PhD with this project.

So there's a lot of opportunity and I would encourage all high school students, all undergrads to look at what University of Minnesota is doing and try to contact us if we can help in any way.

- Wonderful.

Thank you Dr. Sharma.

- Thank you, Dan.

- Stay tuned for more on Farm Connections.

There is strength in the land and it's our responsibility to make sure that we put back in one form or another that which we take.

I'm Dan Hoffman.

Thanks for watching Farm Connections.

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