How powerful floods impact farm soils, crops and water quality in Minnesota

[MUSIC PLAYING] CATHY WURZER: In about 25 minutes from now, Governor Walz will be at the Rapidan Dam near Mankato to talk about flood conditions and recovery efforts in that area. Unfortunately, as you heard, there is more rain in the forecast, something the state does not need right now. And that's especially true for farmers in southern Minnesota.

Joining us right now to explain the flooding impact on things you might not think about is Shane Bugeja, a University of Minnesota extension educator based in Mankato. Shawn-- Shane, excuse me. Shane, thanks for joining us. We appreciate it.

SHANE BUGEJA: No worries. Thank you for having me, Cathy.

CATHY WURZER: I understand that the Rapidan Dam, because of its partial collapse, unleashed decades of sediment that was built up downstream into the Blue Earth River. As we saw, the flooding eroded the riverbank. What does all that dirt do to the river?

SHANE BUGEJA: Right, so one of the themes that we constantly hear, and I've heard from my county commissioners and county administrator, is the power of water. And I think everybody has seen videos or maybe drone imagery of how powerful that river has become. And one of the things that we deal with in agriculture is we want to keep the soil in its place. And then when we have these disasters that happen, that soil's got to go somewhere.

So, obviously, it has consequences for water quality downstream. But a lot of times, I'm thinking about my farmers and my counties and how they're dealing with these floods.

CATHY WURZER: I'm curious about the soils that farmers-- of course, we have so many farmers in the south that have their fields underwater. What are the effects of that?

SHANE BUGEJA: Right, so, it was really kind of a pit in my stomach the last few weeks where you [INAUDIBLE] little puddles turned into ponds, turned into lakes almost, it seems like, on a lot of the fields that our farmers are harvesting or trying to get a crop out of the ground.

So, some of that flood water, if it stays put, obviously the crop will suffer. Usually, once we get past a couple of days, we start to see stress on the crop itself. Once you get past four days, then highly likely that many of the crops could die.

Then we're left with a really bare area after those flood waters or rainwater eventually recedes. And bare soil is nothing you want to see. A lot of times, farmers have to deal with weeds that pop up shortly after. And then, of course, in the meantime, that soil is susceptible to further erosion.

I want to ask, of course, you mentioned water quality, and I'm going to assume that farmers put herbicides on their fields, obviously. All that has washed off, obviously, into the groundwater and nearby lakes and streams. Would that be right?

SHANE BUGEJA: Well, it really depends on the products. One of the things that we worry about is, is because of all of this rain we have, those products that people may have applied, the residual ones, the ones that last in the soil, may not be functioning correctly in those drowned out spots. And once we have weeds growing and, usually, things like waterhemp is a big notorious, quote unquote-- if it gets out, it can put out a seed head very quickly. And then we can be dealing with those seeds for years to come.

CATHY WURZER: I'm wondering about the soil quality moving forward in your area. And I ask that because we're talking about some fertile farm soil around Mankato. I mean, we're talking several inches, right, if not feet. But if that's washed away, what happens?

SHANE BUGEJA: Right, so we look at some of the nutrients that might hitch a ride with soil. Predominantly, we hear a lot about phosphorus, which is an important fertilizer and nutrient for plants. But it holds really tightly to soil. And once that soil takes a ride, so to speak, that phosphorus can come out in places that we really don't want it to.

And my background is in soil science. So any time I see soil moving away, you're thinking about the inputs, the money, the cost, that goes into making those soils fertile. And then seeing it washed away and causing issues elsewhere is very hard to see.

CATHY WURZER: So the crops that are underwater right now, is there any way to replant in time to have an actual crop to harvest?

SHANE BUGEJA: Excellent question. So this is really kind of a dilemma for many farmers. So we have these bare areas. If we do really good weed control, that's great. But you're still dealing with bare soil, which we mentioned the erosion potential. There is another aspect to this where if you don't have any plants growing in a spot for a really long time, you can have fungal problems.

So the fungi that usually are helpful for crops, they can get damaged or kind of get impacted by floodwaters and having nothing growing. And we call that fallow syndrome or flooded soil syndrome. That can impact perhaps the next year's crop. It's too late to plan a lot of different cash crops that we're used to. If you were to put soybeans out there, you may get half of your expected yield, and that's assuming everything else goes to plan.

So cover crops are another option that farmers can use. But it's easy for me sitting in this office, telling people, yeah, just go out and plant cover crops. You have to deal with navigating the crops that you have out there currently, whether you use have to use special equipment to get in there to sow it correctly, pick the right species. And then you've got to figure out what to do with it once the cover crop gets tall.

CATHY WURZER: So it sounds as though the calculus might be just to wait it out until next season, perhaps, and maybe try to get some disaster relief loans or something from the federal government to tide farmers over?

SHANE BUGEJA: Well, yeah, there's programs available for farmer. And I should say some farmers-- or a lot of farmers-- certain vegetable producers, they're farmers, just like everybody else. And they are susceptible to the disasters that we see in our landscape. It can be difficult for vegetable farmers to get some of those crop insurance benefits when it takes a few years to get in the system, so to speak.

So, those are some of the folks that I worry about. And of course, like I said, this is a very complex-- it's very difficult for a corn farmer or a vegetable farmer to kind of figure out what to do with those flooded areas. We just have kind of our-- to watch out for. And it's up to each farmer to kind of make their own decisions about their land. But we in extension are here to help with resource-based information.

CATHY WURZER: Boy, there's got to be a heavy emotional toll on some farmers. This is tough.

SHANE BUGEJA: Yeah, and it's tough on everybody. My office was personally impacted by the flooding. I was making sandbags for Waterville, a town in Le Sueur County. And then the day after, you get the call about the dam in Rapidan. So, some of the things that we urge farmers and people in rural communities is really kind of consider reaching out for help, especially during these stressful times.

So the Minnesota Farm and Rural Helpline is one way to do that, 833-6002670. I urge people to contact it because this can be-- this is devastating. It's hard becoming unproductive or being gone in such a dramatic, devastating weather event.

CATHY WURZER: So I want to circle back to, as you say, you're really into dirt, and you're a soil scientist.

SHANE BUGEJA: Soil.

CATHY WURZER: I know.

SHANE BUGEJA: Soil, Cathy.

CATHY WURZER: Sorry, sorry.

SHANE BUGEJA: Dirt is soil out of place. And I would be remiss, all my educators and all my professors would scowl at me if I said that.

CATHY WURZER: OK.

SHANE BUGEJA: But it's OK, Cathy.

[LAUGHTER]

CATHY WURZER: Because you are a soil scientist, we've just had these extremes, as you know, because of climate change, the imprint of climate change. I mean, we just got done with a two-year drought, for goodness' sakes, and now we're dealing with extreme flooding. How does that impact the soil?

SHANE BUGEJA: Right, so soil has had a hard time recently, as you said, with weather impacts and climate weirdness and changes. The thing about it is, a lot of times, when my colleagues and I were trying to talk about resiliency on a farm and how can we make farm, whether it's a vegetable farm or corn, soybean farm, resilient, can we make our soils resistant to some of these massive weather impacts, sometimes that might take the form of reducing tillage.

That might take the form of considering cover crops if they make sense for your cropping system or other types of sustainable agriculture techniques. Because the soil is really where-- it's where a lot of things begin. And it's not renewable in our lifetimes. And it's something that you almost can think of it like a bank account for all of the nutrients in the soil that your plants access and use all the time. And having that being lost is never good.

CATHY WURZER: Mm. Well, Shane, thank you so very much. I learned a lot from you, and I wish you well. Thank you.

SHANE BUGEJA: Thank you, Cathy.

CATHY WURZER: We've been talking to Shane Bugeja, a University of Minnesota extension educator based in Mankato.