The agricultural portion of that plan was focused on reducing loss of nitrogen and phosphorous through leaching and runoff. The plan recommends a list of cultural practices that producers are encouraged to adopt or expand, to preserve nutrients in their fields and reduce loss of nutrients.
NASS was asked to design and conduct a survey that would establish a baseline set of statistics for some of those practices in the 2011 crop season. In addition, the initial survey was designed to measure those same cultural practices for the 2015 crop season. The survey has been repeated, with very few changes, to gather updated statistics for 2017, 2019, and 2021.
NITROGEN MANAGEMENT For the 2021 survey, respondents were provided a map of Illinois with Maximum Return To Nitrogen (MRTN) rates for three regions in Illinois. Each region had MRTN rates for corn-after-corn acres and corn-after-soybean acres. Producers were asked to report the number of corn acres they fertilized at or below the MRTN rate for their region of the state.
FERTILIZER APPLICATION STRATEGIES (Nitrification Inhibitors): The survey results showed that farmers used a nitrification inhibitor on 85% 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%.
FERTILIZER APPLICATION STRATEGIES (Timing of Applications) Survey results show that nearly 25% of corn acres were fertilized only in the fall or winter. Forty percent of corn acres were fertilized only in the spring, and 35% of acres were fertilized in the fall and spring (split-application technique).
PHOSPHOROUS When asked about the reasons for reducing phosphorous applications, producers gave the responses below:
- Changes to the Illinois Agronomy Handbook removal rates were cited as the reason for phosphorous reductions on nearly 2 million acres.
- Soil test results were cited as the reason for reductions on nearly 4.6 million acres.
- Other reasons, including cost, were cited as reasons for reductions on just over 2 million acres.
COVER CROPS The NASS survey included questions on usage of cover crops prior to planting corn and soybeans. The questionnaire instructed respondents not to count double-crop soybeans planted after a winter wheat cash crop. Results show that farmers planted 450,000 acres of corn after cover crops in 2021, and 890,000 acres of soybeans after cover crops.
The NASS survey also included a series of general knowledge questions about the Nutrient Loss Reduction Strategy and best management practices (BMPs).
Categories: Illinois, Crops