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.
Farming in Iowa with terraces, tile and the truck windows down
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.
Soil management efforts in action
Dennis takes me out to one of the fields that will soon be terraced. In early June, the beans are just starting to poke out between broken corn stalks, chaffe and other organic material (a conservation practice known as no-till). Dennis seems to glide through the rows of young soybean plants, while I constantly fall behind. I tiptoe and try not to step on the young beans. Dennis constantly, yet graciously, has to wait on me.
Walking with Dennis through his fields
We come to a smallish-looking area that had filled with a little too much material. “You can make a real mess out here if you’re not careful,” Dennis says looking over collected mass, “It’s places like this we work real hard to avoid.” Judging by the rest of his near perfectly sculpted 90-acre field, this little gully was very rare.
“If there’s one thing that I’m proud of farmers as a whole,” he continues as we head back to the truck, “it’s our soil management efforts. It’s just a matter of basic business. If we didn’t take care of the ground, we wouldn’t be able to grow anything the next year.”
Next we head over to a water catchment at the south end of the bean field. Further down in the catchment, plastic drainage pipes stick out from about every angle. These tubes are known in the Midwest as “tile” - a holdover from the days when the tubes were made of unglazed clay - and they are one of the single greatest inventions that enabled modern agriculture in Iowa.
Tile drainage keeps water from pooling in low-lying areas, reduces potential soil compaction and enables good root development in the crops. Dennis and Doug tiled their first field in 1998 and had the first terrace built in 1999. Fourteen years later and they continue to monitor and manage how and where their soil moves.
Back inside the truck, I mention something about how great it is to be outside in this weather (mildly hot, sunny and breezy). Dennis smiles, “As long as it’s not blazing hot, I always drive with the windows down.”