In agriculture, wetlands can be a powerful tool used to intercept tile drainage, reducing nutrient loss for water quality improvement. An edge-of-field practice included in the Illinois Nutrient Loss Strategy (NLRS) suite of agricultural conservation practices. Wetlands, constructed or restored, have benefits for water quality and wildlife. While constructing or restoring a wetland can be costly, it is noted that it is one of the most cost-effective solutions for removing nitrate-nitrogen, offering a lasting impact with minimal upkeep. Across Illinois, some farmers and landowners have adopted this practice within their operations.
What’s the difference? Constructed vs. restored wetlands
It can be easy to use the term “wetland” and assume all wetlands are the same, but not all are created equal. The presence of water often defines a wetland, but there are different types of wetlands. Jill Kostel, Water Resources Program Director with The Wetlands Initiative (TWI), explains the difference between a restored and constructed wetland.
A restored wetland is put in place to restore the natural hydrology and native vegetation in a former wetland that was drained, farmed, or otherwise modified to restore wetland function, habitat, and diversity.
On the other hand, a constructed wetland is an engineered ecosystem built anywhere but a former wetland designed to mimic a natural wetland’s ability to clean water. Constructed wetlands are often used to intercept a tile main and provide optimal conditions to remove excess nutrients, primarily nitrate-nitrogen.
Wetlands and water quality
Wetlands provide many services for people and the planet, and one of the most significant is improved water quality. Constructed wetlands are designed to be implemented at a tile drain outlet and can intercept water from 30 to 200 acres.
These wetlands are in place to capture the tile-drained water and act as natural filters. While the plants in the wetland take up some nitrates, most of the heavy lifting is done by the microbial community which converts the nitrate to nitrogen gas. According to Kostel, constructed wetlands, if designed and sized properly, can remove at least 50% and potentially up to 90% of the nitrate-nitrogen from tile water.
A farmer’s perspective
Rex Newton, who has farmed in Marshall County, Illinois, for the past 50 years, is one of the farmers TWI has worked with to install a constructed wetland. Newton said that the 2.8-acre wetland and pollinator habitat requires very little maintenance, yet he has already observed an increase in local wildlife and Monarch populations.
Monitoring is done on this wetland to measure the nitrate levels in the water entering and leaving the wetland. Newton says that he is excited to see the results, which will help reinforce that he’s doing the right thing, which is rewarding.
For other farmers interested in adopting a wetland, Newton highlighted the importance of support. For him, having a conservation-minded landlord helped with the plan. His advice also included patience. While some areas of construction happen quickly, plant establishment takes time.
To listen to the full interviews with Jill and Rex, check out Episode 70 of the Nutrient Loss Reduction Podcast.
About the authors
Rachel Curry is an Agriculture and Agribusiness Educator specializing in agriculture and watershed education, and she is part of the Illinois Extension's Nutrient Loss Reduction Strategy implementation team. She holds a B.A. in Environmental Studies from Knox College and an M.S. in Environmental Science and Soil Science from Iowa State University, focusing on soil fertility. Her work centers on education and outreach related to the Illinois Nutrient Loss Reduction Strategy, promoting agricultural conservation practices that reduce nutrient loss while enhancing water quality and soil health across Illinois.
Nicole Haverback serves as a Watershed Outreach Associate and is an Illinois Extension team member implementing the Nutrient Loss Reduction Strategy. She holds a B.S. in Agriculture and Rural Policy Studies from Iowa State University. In her role, Nicole coordinates watershed management and planning efforts aimed at reducing nutrient losses in priority areas, offers expertise on best management practices to minimize nutrient loss, and leads outreach initiatives promoting agricultural conservation practices outlined in the Illinois Nutrient Loss Reduction Strategy.
About the blog
At Illinois Extension, we’re working to improve water quality at home and downstream. Every month, our Watershed Outreach Associates will bring you stories highlighting agricultural conservation practices, current research projects and results, and from the field farmer interviews. The Nutrient Loss Reduction blog covers conservation practices recommended by the Illinois Nutrient Loss Reduction Strategy, timely updates, farm safety, and new decision tools to help farmers and producers reduce the nutrients leaving their field.