Below the Surface

Iowa is synonymous with agriculture. Our state is renowned for its rich soil, and its farmers often claim that they "feed the world." The landscape is largely vistas of corn and soybeans in the warmer seasons, swathes of bare stubble over the winter, pocked with towns and cities scattered along rivers and other areas favorable to human populations.

This soil, the source of generations of wealth and well-being, is a legacy of the prairies that once covered this land. Deep-rooted prairie plants grew, died, and decomposed for millennia, building up many inches of nutrient-rich earth held in place by those long, spreading roots. Rainfall could infiltrate the land, penetrating the surface and sinking below to water the grasses and forbs that grew.

 Over time, those prairies were plowed under and replaced with crops. In recent decades, the crops became largely huge monocultures of corn and soybeans. Gone was the diversity of plant, animal, and insect species that once reigned. The rich soil, no longer held in place by those deep-rooted prairie plants, washed away in heavy rains, clogging rivers and carrying fertilizer and pesticides with it. Rivers, lakes, and other waterways become impaired by the runoff, requiring treatment before it can be used for all the necessities that water is used for.

Corn monoculture

Even as the prairies gave way to farmland, farmland gives way to concrete. Expanding towns replace corn fields with houses and roads, scraping away or covering over what is left of that rich soil millennia in the making. How we take for granted that rich heritage of the prairies, and how easily we watch it go to waste.

Think about the earth under a prairie, or beneath a wooded ravine. Stretching roots; burrowing mammals; digging worms and insects. The sun warms the surface while rain and snow deliver moisture at intervals. Seeds dropped by passing birds or blown by a strong breeze find purchase and grow into new generations, providing food and habitat for many other species beyond their own.

Soybean monoculture

Now think about the earth under a field of corn. Shallow roots, unwilling to share the earth with other species--plant, insect, or otherwise. It does not thrive on the meager bounty of sun and rain that sustained life for thousands of years before the arrival of monoculture but instead relies on inputs of fertilizer to fuel growth and pesticides to keep out any  unwanted life.

And then--imagine the earth under a parking lot, or a paved road. No water can reach it; the sun bakes the artificial surface but gives no life. The only roots are those that stretch sideways from the nearest open patch of land hospitable to plant life. Does anything live below that surface?

The soil made Iowa what it is today. The prairies made that soil. As we consider how our state has changed over the past couple of centuries, and how it will continue to change, we should always be mindful of whence our state's greatest wealth came. How long it took to develop, and how quickly we have lost so much of it.

A slightly more diverse landscape

Let's imagine what we could do to begin to build and restore even small parts of the land and preserve its life-giving functions. Make sure that every acre paved and every foundation laid is absolutely necessary, because it is far too easy to destroy the work of generations for a short-term profit.

Organizations working to preserve our state's natural heritage:

• Sustainable Iowa Land Trust: dedicated to preserving land for sustainable agriculture
• Bur Oak Land Trust protects and conserves natural areas in and around Johnson County
• Iowa Natural Heritage Foundation, helping to protect and restore Iowa's land, water, and wildlife
• Nature Conservancy in Iowa, working to preserve our state's natural landscapes

A Lonely Straggler

A mixed flock of sparrows--House and Eurasian Tree--swoop back and forth across the Greenway trail, from the brush to the east into the corn stubble in the west. Soft chirps punctuate the still air, as their pale bellies glow yellow overhead in the fading afternoon sun. Glittering black eyes watch, wary, as the approach of an ungainly, unfeathered biped sets off a hopscotch wave of individual birds flit past their neighbors to keep a safe distance from the intruder.

A few sparrows settle in a tree ahead, where a larger bird sits silent. It's a male Red-Winged Blackbird, his crimson epaulets hidden. He is not defending territory or wooing the ladies--that will come later, in the spring. For now, he is riding out the winter. Why is he here after so many of his brethren have migrated away to the south? Who can say?

Data for Johnson County show that the abundance of Red-winged Blackbirds peaks during spring migration, in early March, with more than 80 birds reported on count sheets on average. There is a slightly lower peak for fall migration, in mid-October, averaging just under 50 birds reported. Throughout the summer breeding season numbers are fairly steady between 5-10 birds reported, as birds leave migratory flocks and settle in territories established by individual males upon their return from wintering grounds.

But in December? Nearly nothing! eBird data shows that for the months of December and January, in the past hundred and some years only a single record shows up at the Sycamore Wetlands, for 7 birds on 12/12/17, with just a scattering of other records around Johnson County. Is this fellow alone, left to struggle for survival until the other blackbirds return in a few months? Does he have unseen friends lurking in the area to keep him company?

Though their summer diet is largely made up of insects, blackbirds will also eat waste seeds and waste grain, including corn (which should be in good supply in the fields around the Greenway).

So good luck, my unseasonable friend! Stay warm, stay safe, and I hope to see you again.