By Tim Alexander
SPRINGFIELD, Ill. – The USDA’s National Agricultural Statistics Service (NASS) released the results of their 2021 survey of 1,095 Illinois farms regarding field nutrient usage as part of Illinois’ Nutrient Loss Reduction Strategy (NLRS), reflecting a significant increase in approved field nutrient conservation strategies adopted by farmers.
“The primary NLRS goals are to reduce annual loading of nitrate-nitrogen and total phosphorus to the Mississippi River and address the impacts on local water quality,” said Jeff Kirwan, chair of the Illinois Nutrient Research and Education Council (NREC), which works in parallel, but independently, with the NLRS.
“The ultimate goal is to achieve 45 percent loss reductions in both nitrate-nitrogen and total phosphorus with the interim loss reduction goals of 15 percent nitrate-nitrogen and 25 percent total phosphorus by 2025. Illinois farmers have been making tremendous strides at voluntarily implementing BMPs (best management practices) that make sense for both their farms and the environment.”
With a focus on reducing loss of nitrogen and phosphorus from field leaching and runoff, the NLRS, issued in 2015, includes a list of cultural practices that producers are encouraged to adopt or expand to preserve nutrients in their fields.
Survey respondents were provided a map of Illinois with Maximum Return To Nitrogen (MRTN) nutrient application rates for three regions in Illinois, with MRTN threshold rates for corn-after-corn acres and corn-after-soybean acres Respondents were asked to report the number of corn acres they fertilized at or below the MRTN rate for their region of the state.
The survey results showed significant progress in the number of acres fertilized at MRTN or a lower rate, with nearly 8.4 million acres at MRTN or lower in 2021, compared to about 4.2 million acres in 2019 and more than 3.7 million acres in 2017.
In addition, the survey showed that farmers used a nitrification inhibitor on 85 percent of corn acres that were fertilized with anhydrous ammonia in the fall or winter. For anhydrous ammonia used in the spring, that ratio was 83 percent.
“We’ve invested over $30 million in research in this state through a lot of universities looking at different concepts and practices farmers can use,” Kirwan said. “We’ve done a lot of research into MRTNs and developing nitrogen strategies for farmers. We’ve looked at cover crops, edge of field practices, bioreactors and saturated buffers, measured them and performed the research to determine their contributions to helping us solve some of the challenges that we have.”
Kirwan was pleased to see the increase in the number of acres adopted for nutrient best management practices by Illinois farmers, but credited some of the increase, ironically, to higher crop input prices and effects of the most recent economic downturn.
“When you think about farmers and the environment we’ve been in for the last couple of years with our input prices going up, there’s a lot of push in the ag community to be more efficient and more strategic about how we place fertilizers, and where we apply them,” Kirwan said. “(NREC) has been able to supply the research that shows things you can consider and adopt on the farm, and that’s why I think you are seeing this drive to (nutrient management) adoption throughout the state. We hope that that continues.”
Though USDA’s 2021 NLRS polling of Illinois farmers illustrates a significant rise in the number of adherents to the policies of the Survey, an increase in above-average precipitation and flash flood events across Illinois has prohibited farmers from making much headway toward the NLRS’ short and long term goals. This is according to the 2021 NLRS Biennial report, which showed that since 2019 – the publication date of the previous biennial NLRS report – nitrate losses had increased around 13 percent, while phosphorus losses increased by 35 percent above previously established baselines.
Despite the alarming report, Kirwan advised farmers to stay the course in their commitment to nutrient conservation, while keeping abreast of the latest research into nutrient management practices.
“On my northwestern Illinois farm, we are using cover crops, and we actually have tile lines feeding into a wood chip bioreactor. We are seeing extremes in weather events and a lot more rain. From my personal experience I’ve seen the benefits of that cover crop greening in the spring and helping hold that soil in place through these torrential rains,” said Kirwan, who worked with Dr. Laura Christenson, founder and co-lead of the Illinois Drainage Research and Outreach Program at the University of Illinois, through the NREC to make bioreactors more simple and affordable for farmers to use and purchase.
Despite the setback in nutrient retention brought forth in the 2021 NLRS Biennial Report, Kirwan sees the USDA survey results as cause for cautious optimism. “We’re not seeing quite the reductions that we want to see, but we are definitely working in the right direction,” he said.
“I liken this process to asking more questions in order to source more questions about more things we should be looking at. But, ultimately, I think we are having an impact and I think you’ll continue to see that looking forward.”
To view a copy of the recently issued USDA-NASS Illinois NLRS Survey results, visit 20220804-IL-Final 2021 NLRS Results and Writeup.pdf (usda.gov).