Managing Water on the Farm

[Abby Brown] You've probably noticed how Iowa's farmland changes throughout the year. From planting season in the spring, to growing season in the summer, and harvest in the fall. But you might not have noticed the special places where grass is planted. Or the specific way a hill is designed to let water fall in just the right direction. These are special ways farmers take care of their land. Even the way some crops are planted up on shelves is designed to take care of our precious Iowa soil and keep the water in our rivers and streams clean.

[Abby] Agriculture in Iowa is such a success because of how special our soil is, especially the soil right at the top, the topsoil, because it is full of nutrients that help corn and soybeans and all sorts of other seeds grow.

[Abby] When it rains in Iowa, our crops get exactly what they need. The challenge is when a field gets too much rain all at once. That extra rain washes away into other waterways and when it does, it can take chemicals from the soil with it. Those chemicals, or nutrients, that make our soil so great for growing seeds just aren't good for the water. Farmers and conservationists have come up with some really clever ways to help make sure that topsoil stays put. Let's check it out!

[Abby] All right, Shawn, tell me about this first way that we have to conserve water.

[Shawn] So what we're looking at here is a water control structure. And this is a part of many soil and water conservation projects and the different practices that we're able to do to help reduce sedimentation, reduce nutrient losses.

[Abby] So, where does the water come from that this structure is using?

[Shawn] So, from the building behind us, off of the roof, through the gutter there it comes down --

[Abby] So when it rains, collects the rainwater --

[Shawn] All the water comes off the roof, goes down through the gutter and through a tile line underground into this water control structure.

[Abby] What is a tile line?

[Shawn] So, a tile line is typically an underground pipe, plastic or otherwise, that helps provide drainage in many cases for farmland to help remove excess water. But in this type of situation we're using it to actually capture water and direct it to where we want it to go.

[Abby] Okay. And where do we want it to go this time?

[Shawn] In this case, the water from the roof is being diverted over here into a rain garden where it helps slow that water down, spread it out and infiltrate through the natural filter we have in our soil.

[Abby] So, when it rains all the water from that roof comes through the water structure into a tile and comes out here. Now, when I think of a garden I think of plants growing. But this is just grass.

[Shawn] Yeah, so it's an urban rain garden so we don't see any tomatoes or anything like that in here obviously. So it's a native plant garden if you want to think of it that way. So it's a nice dedicated spot where we can have some plants that will utilize that water and also help reduce erosion and all those things we want to see.

[Abby] So, if you wanted to plant some flowers right here or something it would be a great place to do it.

[Shawn] Yeah, it would be a great place if you wanted to plant flowers or native grasses, that type of thing, really anything you'd want to do here. You've got a nice water source that always comes in, helps those plants grow, so really up to you what you decide to plant.

[Abby] But the point is that it slows down the water and it does that job.

[Shawn] Yeah, it does a great job slowing down that water. It really helps that infiltrate through the soil using the natural filter and achieves all the things we want to see.

[Abby] Perfect.

[Abby] So behind us is a pond and around it there's lots of grasses and even flowers planted and that helps slow down water too, right? How does that work?

[Shawn] It sure does. Not only the vegetation above ground but the roots below ground do an excellent job of collecting nutrients and helping clean the water.

[Abby] Sure, so we're kind of down in a valley. So you're letting gravity do the work and the rain comes down and whether it runs down the hills or comes down in those tiles it comes into the roots in all the grasses and it stops those nutrients from getting in the water, right?

[Shawn] That's correct, yeah.

[Abby] Now to the left of us we have almost like shelves in the ground and those are called terraces, right? So how do those help?

[Shawn] Well, terraces are a very common practice in Iowa and what they do is they segment the hills. The hills are generally fairly long in Iowa so the terraces we get them in the shorter segments. So when we get heavy rain events, the rain would hit that barrier and stop gully erosion from forming or sheet and rill erosion. So we want to try to segment the hills into shorter segments.

[Abby] Because if you don't tell the water where to go it's going to create its own pathways and that is no good. We want it going right where you pick.

[Shawn] That's right.

[Abby] Behind us is what we call a wetland. And tell me, how does a wetland help farmers?

[Shawn] Many wetlands provide many natural functions. They are often called the kidneys of our landscape where they help filter out nutrients.

[Abby] So my kidneys clean my blood, how does this wetland clean the water?

[Shawn] It's a filter. So it filters out pollutants, natural things that we don't want to have in our water as it goes on downstream.

[Abby] How does it do that?

[Shawn] So, there's naturally occurring organisms, they basically use some of those things as food, they consume them, they use the nutrients for the plants to grow so it's a natural process where everybody is benefiting from what is coming into the wetland and we benefit from improved water quality going downstream.

[Abby] That's perfect. So the plants and the creatures that live in there actually eat the nitrates, which is exactly what we want to get out of the water.

[Shawn] That's right.

[Abby] And way behind the wetland is a grass waterway. And I've seen those before. It looks just like grass planted in the middle of your field. So how does that help?

[Shawn] It's exactly what it sounds like, it is a place where the rain would naturally want to flow down the hill and by putting grass there it helps slow that rainfall down and keep it from eroding the soil.

[Announcer] Funding for FIND Iowa has been provided by the following supporters.

(text on screen Find Iowa, Coons Foundation, Pella, Gilchrist Foundation)

(text on screen Iowa PBS Education)