Myth Busting - Conservation Edition
February 9, 2023
Contributed by Iowa Agriculture Water Alliance (IAWA). IAWA is partially funded by Iowa Soybean Checkoff and was founded by ISA, Iowa Corn Growers Association and Iowa Pork Producers Association
The Iowa Nutrient Reduction Strategy (Iowa NRS) turns 10 this year. It’s a scientific framework to reduce nutrient losses, and the Iowa Ag Water Alliance is a key partner in helping achieve that goal. While Iowa farmers have been implementing and innovating conservation practices long before the adoption of the Iowa NRS, there are still a lot of misconceptions about conservation practices. Can you tell myth from fact?
Myth or Fact: Cover crop adoption has increased by 344% since 2016. FACT.
Yes, you can grow cover crops in Iowa. According to data from the Iowa Nutrient Research and Education Council and Iowa NRS, cover crop acres in the state increased from 623,000 acres in 2016 to nearly 2.8 million acres in 2021. Rye remains the most popular cover crop because it’s easy to grow and terminate. It’s also forgiving. Rye that’s established in the fall will overwinter and provide cover in the spring ahead of planting, which keeps your soil where you want it and reduces nutrient loss.
Myth or Fact: Conservation practices aren’t profitable. MYTH.
In-field conservation practices like cover crops and no-till can save farmers money.
“In front of soybeans, cover crops play a key role in suppressing herbicide resistant weeds,” says Scott Nelson, Iowa Soybean Association (ISA) senior field services manager. “Using no-till means less wear and tear on machinery and saves in fuel costs.”
Myth or Fact: Bioreactors, saturated buffers and water quality wetlands are new practices in Iowa. MYTH
Iowa farmers lead the nation in the number of installed water quality wetlands, saturated buffers and bioreactors. These are all strategies placed on the edges of fields to filter water before it moves downstream. According to the Iowa Department of Ag and Land Stewardship, there are more than 125 water quality wetland sites, 150 saturated buffers, and 100 bioreactors in the state.
ISA has played a major role in pioneering these edge-of-field practices. ISA and Iowa State University (ISU) worked together to help develop the NRCS practice standard for bioreactors, and ISA was one of the first to “recharge” a bioreactor that was originally installed in 2008 — replacing the old wood chips with new. ISA has also worked with ISU to make these structures low maintenance for farmers.
Myth or Fact: Fertilizer efficiency in the field is impacted by billions of possible factor combinations, including soil type, weather and cropping system. FACT.
“Research shows that the optimum rate of nitrogen (N) can vary by more than 100% from field to field and year to year,” says Dr. Mike Castellano, ISU agronomy professor.
Dr. Castellano heads up the Iowa Nitrogen Initiative, which addresses these field-to-field and year-to-year differences through on-farm nitrogen trials. The data produced will be used to create tools that will help farmers save money by helping them decide the most efficient amount of fertilizer.
While these tools are under development, farmers can soil test for residual nitrate levels to better estimate how much N to apply each season. Farmers interested in participating in the Iowa Nitrogen Initiative can reach out to an ISA conservation agronomist to learn more.
Myth or Fact: Farmers, hunters, neighbors and wildlife all benefit from water quality wetlands. FACT.
Wetlands provide multiple benefits such as more habitat for pollinators and wildlife, which also benefits hunters, and improves water quality for neighbors. Farmers benefit, too. These wetlands take minimal land out of production and treat, on average, 52% of nitrates from field tile.
For example: Mark Mueller, a farmer in Bremer County, installed a water quality wetland in 2022. This wetland is on what is called a breakpoint site that was historically wet with lower yields. Installing a wetland in a less productive spot means cost savings for Mueller over time because inputs aren’t being wasted. Mueller’s water quality wetland is only 2.86 acres, but it treats 446 acres.
“Whether 100 miles downstream or 100 years in the future, this wetland will remove nitrates and clean up the water for the benefit of generations not yet born,” says Mueller.