A Reminder from One Eastern Iowa Farmer: Don’t Forget Grassed Waterways
A Reminder from One Eastern Iowa Farmer: Don’t Forget Grassed Waterways
Clark Porter
Awhile back, we often heard people in rural America lament the fact that they lived in a “flyover state.” In competition with the glamour of New York City, or the political clout of populous California, how could western Kansas, for instance, attract any attention? Grassed waterways are kind of like the flyover states in our fields. Compared to the aesthetic appeal of cover crops, the verdant green of buffer strips, or the impressive techno-wonkiness of woodchip bioreactors, a grassed waterway is often ignored. However, waterways are the workhorse of soil conservation and water quality. They are as unglamorous as they are effective, and keeping them maintained is a challenge.
This fall, while many of us were tilting one ear skyward in case we heard a command to build an ark, I was out collecting water samples in and around a field owned and farmed by Nick Meier, in the Miller Creek Watershed of Black Hawk County. On one day just after the deluge, enough water was running through one of Nick’s waterways to host an Olympic kayaking event. While this was impressive, even more impressive was how clear this water was. No sediment was being carried across Nick’s waterway (pictured), and all of it flowed towards a buffer strip along a streambank filled with stiff-stemmed prairie grasses.
Nick credits the effectiveness of his waterways with regular maintenance. For instance, he keeps it regularly mowed. Certainly, there are guidelines about mowing waterways during the nesting season – and many of us want to see waterways function as habitat. However, Nick believes in relying on other areas of his farm (such as buffer strips) for habitat. A well-mowed waterway will not channel water outward, forcing it to cut ruts along the border and carry sediment downhill.
Nick periodically grades the sides of his waterways, assuring that water flows into the structure and not alongside it. The contractor he hired to construct his waterways routinely incorporates mild swales that angle towards the waterway. These are placed every 150 feet.
Nick repairs and reseeds the waterways. He is cautious about not allowing them to shrink when subjected to the seasonal abuses of planters, sprayers, and harvest equipment. Also, after years of no-tilling, strip-tilling, and cover cropping, Nick’s soil biology is healthy. His fields are full of worm middens and aggregated soil. Water absorption and ground cover mitigate against the transport of sediment and the insults of surface water. All of this keeps his waterways from being overwhelmed.
It is true that we may overlook old-fashioned standbys in favor of the exotic appeal of something new and noteworthy. However, this is Iowa. Sometimes we prefer ketchup to gochujang, and does it matter if your sandwich has lettuce instead of arugula? So don’t forget to pay special attention to the humble conservation workhorse in your fields – the grassed waterway.