June 16, 2017
By Liz Clift
Iowa became part of the heart of American agriculture, due to the rich—and thick—topsoil it contained as white settlers moved across the plains. Iowa’s nutrient-dense is, in part, due to Iowa’s placement between the Missouri and the Mississippi Rivers, which form the majority of the eastern and western borders of the state. The floodplains from these rivers built up stores of nutrients, as did the history of large grazing herbivores that would have once dominated the plains, including bison, elk, deer, and even mastodons.
Unfortunately, that topsoil is disappearing. In the 1850s, Iowa had 14-16 inches of top soil; as of 2011, it had about half that. In 2014, parts of Iowa lost 15 million tons of topsoil due to erosion caused by storms. The remaining soil is being stripped of nutrients, due to monocropping, which over time, depletes certain nutrients from the soil. Even when fields are left fallow or with a cover crop for a season or two, the nutrients are not necessarily returned to the soil.
There’s a joke I heard shortly after I moved to Iowa in the mid-aughts:
Person 1: Have you seen the four views of Iowa?
Person 2: The four views of Iowa?
Person 1: Yeah. Corn on the left, [soy] beans on the right. Beans on the left, corn on the right. Beans on the left, beans on the right. Corn on the left, corn on the right.
During the growing season, that’s pretty much true.
And it means that most people don’t understand how much natural beauty Iowa once had—and still has. The prairie plants that historically grew in the area are notable for their long root systems. These root systems not only helped stabilize the soil and retain moisture (or get to moisture during drought years)—the roots also helped prevent soil compaction and drew nutrients further beneath the surface of the soil toward the top, making these nutrients more available for plants with shallower root systems, and younger plants.
There are only isolated prairies now, many restored, some historic. Some farmers are moving toward more sustainable, or even regenerative, agricultural practices. If you’re driving or biking across Iowa’s rolling hills, you might find yourself admiring a polyculture farm that includes nut trees, fruit-berry bushes, and row crops, with ducks or chickens roaming about. You might find yourself alongside someone’s land that’s been put into the Conservation Reserve Program (CRP), which has historically paid farmers to remove land from agricultural production and plant species that will improve functionality.
Of course, in Iowa (and elsewhere), there is a lot of focus on what agricultural practitioners—which I’ll classify as everyone from conventional farmers through prairie restorationists—are getting wrong (or right). Who is getting what wrong or right, in many cases, appears to be dependent on what, specifically, any individual’s priorities are.
As we think about what’s going right or wrong, we must also remember that we have made major changes to the way the Midwest looks—including the use of agricultural tiles that effectively keep the land from becoming swampy, the removal or extinction of large herbivores, controlling of fires, the decimation of native plant species, and channelizing streams and rivers. Some of these things are more easily remedied than others.
Great Ecology is working to reconnect an Iowa stream with its floodplain, which will include some native prairie restoration. There are prairie management activities, which may include prairie burns, meant to replicate some of the more natural processes that enable tallgrass prairies to survive. A prairie conference occurs each year in the Loess Hills (this year is focused on restoration, reconstruction, and protection). Certain agricultural practices, including CRP, facilitate the rebuilding of the soil and its nutrients. Some individuals are transitioning bluegrass lawns into native grasses.
And these are just a handful of the activities that could work, or are working, to maintain or improve soil health.
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