Farming in Iowa with terraces, tile and the truck windows down
Soil moves. Even though we might not see it, it’s moving all the time. That was the big lesson I took away from my visit to Dennis Seyb’s family farm located just outside the town of Donnellson, Iowa.
The town sits in the southeast corner of the state, about 15 miles west of the Mississippi River. Dennis and his wife Liza, along with his brother Doug and son Tucker grow corn, soybeans, wheat, hay and other grains along with pigs and cattle on some pretty hilly patches. The American Midwest is often described as one big open field. People hear “Corn Belt” and think of fields that go on forever, of a horizon line that belongs in another state. But here in Lee County, “It’s not flat,” as Tucker puts it.
From moving soil to rotating crops
That means, for one thing, the Seybs have had to master the skill of a driving tractor sideways across a hill without tipping over. More importantly, all the hills and valleys mean that rainwater, wind and gravity are constantly working to carry the soil - and everything planted in it - down toward the field bottoms and streams. The Seybs constantly monitor and manage the movement and health of the soil. So they plant cover crops of rye and oats. They practice steady crop rotation, regularly switching from broadleaf plants like soybeans into grasses such as corn and back again. “This kind of rotation also helps keep plant diseases in check,” an important point that Dennis adds almost as an afterthought.
Terraces make the difference
Terraces within the field help to prevent the soil. And they build terraces, lots and lots of terraces. Terraces, Dennis later explains, keep water from creating gullies and washing out the crops and other organic material. Dennis’s terraces range from small, three-foot mounds (ca. 1 meter) to large, “steepback” terraces nearly 6 feet tall (2 meters) and more than 300 feet long (100 meters).
To move that much dirt around and do it successfully, it takes careful planning and coordination. That means first surveying for proper drain direction, then bringing in big machines to move around a lot of soil. Just as I arrived at the farm, Dennis and his brother drove up. They were just returning from a visit to the local conservation office, where they were scouting maps to plan their latest terrace building project. Step one was almost complete.
