Story courtesy of Freeborn County Soil & Water Conservation District
A fairly new technology in agricultural conservation is gaining some attention in Freeborn County. Larry Bidne, who lives and farms near Emmons, recently decided that controlled drainage would be beneficial on a field he rents just west of Bear Lake. Controlled drainage is a great way to hold water in the soil and make it available to crops when needed.
Controlled drainage systems work with existing drain tile. The perforated pipes that landowners install under farm fields to carry away excess moisture are referred to as drain tile. The controlled drainage systems can be inexpensive to install.
Here’s how it works:
- Water control structures are installed on the tile lines. The system uses boards to control water levels in the soil. Farmers remove boards to meter out water and insert boards to retain water.
- Water control structures are usually placed near the edges of fields, so they are easy to farm around and access during the growing season.
It also helps protect water resources downstream by holding back water that could carry phosphorus and other nutrients from fertilizer. Phosphorus contributes to algae growth in the water, which can harm fish and other aquatic life and make the water unattractive for swimming and other recreation. Holding back water after storm events also cuts down on high flows that can erode fields and streambanks. Erosion leads to sediment in the water, where cloudy conditions make it hard for fish and aquatic insects to find food, avoid predators, and more.
The area near Bear Lake is very sandy, and the water table is regulated by the lake level. In a wet season, Bidne can hold back water with the controlled drainage system and reduce minor flooding that would otherwise harm his crops. In a dry season, he can meter out the water to help the crop grow.
In the Winnebago River Watershed, controlled drainage will help reduce nutrient and sediment pollution in Bear Lake, State Line Lake, the Winnebago River, and water resources downstream in Iowa.
Bidne also uses reduced tillage, a practice that builds soil health and prevents erosion. He is one of many farmers in the Winnebago River Watershed who are implementing best management practices that benefit farming and water quality. The Freeborn County Soil and Water Conservation District (SWCD) works with landowners and farmers to adopt practices that leave the land and water in better condition.
The Winnebago watershed is 688 square miles in size, with 71 square miles in Minnesota and the rest in Iowa. It includes the cities of Conger and Emmons in southern Freeborn County. The Winnebago chain of water resources starts with Steward Creek in Freeborn County, and ends when it flows into the Cedar River, which is the source of drinking water for Cedar Rapids, Iowa.
The SWCD has been part of extensive studies, led by the MPCA, in the Winnebago and neighboring Shell Rock River watersheds the past few years. The studies identified several impairments (bodies of water that fail to meet water quality standards) as well as strategies to restore and protect water sources. Learn more about the studies:
The SWCD collects data in the area on the crops planted, crop residue type, tillage type, crop residue percentage, and any special features noted in fields such as wet spots, tile intake, soil erosion, or wetland restorations. The information helps the SWCD and producers decide on future cropping practices and best management practices.
The SWCD also conducted many one-on-one interviews with landowners, land renters, and other county entities to gather information on the watershed. The MPCA, SWCD, and other partners used this information to detect trends and other noteworthy situations for developing the MPCA's studies. The SWCD staff also held public meetings, gathered input from residents on watershed priorities, and kept stakeholders informed.