Engineered Farm Fields to Protect Water and Soil

The South Kinnickinnic Farmer-Led Watershed Council consists of farmers and agricultural landowners who are interested in seeing farmers in the neighborhood continue to grow crops profitably while also minimizing soil and nutrient loss from their fields. In the KinniKeeper Newsletter, we shared a few details on how that can look with in-field agronomic practices that protect soil. This article will explain a couple of other measures farmers with erosion troubles can add to their fields. These engineered practices are a big investment but can make a big difference in erosion. However, these structures need to be engineered based on the slope of the field and the needs and are often formed in partnership with agencies and excavators who can provide technical assistance.

Grassed waterways are very common throughout Pierce County, WI. With our steep slopes, farmers in the county have long realized the importance of slowing down water as it runs down the hills within fields. The best way to slow down rainwater is often by adding a grassy zone where the water is likely to flow. The roots and blades hold onto the soil so it doesn’t get washed out as rainwater funnels through, and also slow the water down as it travels to reduce its capacity to pick up more debris as it travels. This gives the soil a better chance to infiltrate the water instead of diverting it quickly to nearby ditches and ultimately rivers and lakes. Results from Wisconsin Discovery Farms studies have shown that adding grassed waterways, even in no-till fields, can reduce sediment loss by 99%! Because of their importance, the South Kinni Farmer-Led Council provides an incentive payment per foot to farmers or landowners installing waterways onto their fields. (see graph at bottom of page)

One other engineered practice you’re likely to see farmers in the watershed investing in is what we refer to as dams or grade stabilization structures. These earthen structures are often created where large gullies have formed and are creating huge washouts in tree lines just off the field. The site is re-graded and designed to slow down the water to allow it to infiltrate naturally with stabilized outlets when the dam overflows in heavy rain events. In 2022, Pierce County Land Conservation Department celebrated the installation of their 1000th dam. These dams reduce surface runoff by 67% on average.

Although these projects do have some cost-share options, they represent a significant cost to build (as well as time!). We are so thankful that farmers in our area understand the importance of setting land aside and investing in their soil and water quality.

If you’d like more information on the South Kinnickinnic Farmer-Led Watershed Council or want to learn about applying any of these practices on your farm, you can find us online: https://farmerledwatershed.org/south-kinnickinnic-watershed/ or by following us on facebook.com/farmerledwatershed.

If you want to ask a question directly regarding farmland conservation or the South Kinni Farmer-Led Watershed Council, you can contact Tara Greiman-Daun at tdaun@wisconsinfarmersunion.com at 715-492-0329

Figure 1: Source UW Madison Extension Division of Agriculture Water Quality. See full article: https://agwater.extension.wisc.edu/articles/grassed-waterways-are-fundamental-in-reducing-erosion-and-impacting-water-quality/?fbclid=IwZXh0bgNhZW0CMTAAAR3qproYMQ1Qa6gbiUbOMu-U2HHQRTHi0_qXljAKQMztjNa4sOnzJc3TDcA_aem_ISJC9U6mfGYdqeABt-CRwA