Nutrient Loss Reduction Strategy Survey Results (Illinois)

Illinois
Nutrient Loss Reduction Strategy
Survey

Released July 31, 2024

BACKGROUND AND PURPOSE OF SURVEY
The State of Illinois developed a long-range plan, the Nutrient Loss Reduction Strategy (NLRS), to reduce the loss of
nutrients from agricultural fields (non-point sources) and to address urban runoff (point sources). The agricultural
portion of that plan was focused on practices to minimize the 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 maximize
nutrient retention while reducing nutrient loss.
NASS was asked to design and conduct a survey that would establish a baseline set of statistics for the targeted practices
in the 2011 crop season. After establishing a baseline, the survey was conducted biannually from 2015 through 2023.
The data from the follow-on surveys were gathered to measure the adoption of the targeted practices.
ACKNOWLEDGEMENTS
The staff of NASS would like to thank the Illinois Nutrient Research Education Council (NREC) that provided the funding
for this project as part of their research and education outreach.
NASS staff would also like to thank all the producers that responded to the survey.
SURVEY METHODOLOGY
SAMPLING: NASS staff drew a sample of 1,100 Illinois farms with at least 100 acres of cropland and less than
5,000 acres of cropland.
DATA COLLECTION: NASS mailed questionnaires and return envelopes to producers in February 2024. A second
mailing was sent to non-respondents in March. Following the second mailing, field staff phoned the remaining
non-respondents in March and April.
REFERENCE YEAR: The 2023 crop season was the reference year for nearly all the survey questions. The General
Knowledge questions are referenced to the time of the interview, in early 2024.
NITROGEN MANAGEMENT
For the 2023 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 the region of the state in
which the corn was planted. The map and cover letter referenced here can be found in appendix B.
In the table below, data for the 2021 and 2023 crop seasons are not directly comparable to results from previous
surveys as the data collection process was changed significantly.

Nitrogen Management
Strategy
Corn acres planted
Corn acres fertilized at MRTN or
lower rate

Acres in
2017

Acres in
2019

Acres in
2021

Acres in
2023

11,200,000

10,500,000

11,000,000

11,200,000

3,730,000

4,240,000

8,360,000

8,880,000

Illinois
Nutrient Loss Reduction Strategy
Survey

Released July 31, 2024

FERTILIZER APPLICATION STRATEGIES (Nitrification Inhibitors): The survey results showed that farmers used a
nitrification inhibitor on 87% of corn acres that were fertilized with anhydrous ammonia, also known as NH3, in the fall
or winter.

Nitrogen application including inhibitors on corn acres in Illinois
Corn acres planted
Corn acres fertilized in
the fall and winter with
dry fertilizer blends
Corn acres fertilized in
the fall and winter with
anhydrous ammonia
Corn acres fertilized in
the fall and winter with
nitrification inhibitors

2017
11,200,000

2019
10,500,000

2021
11,000,000

2023
11,200,000

N/A

N/A

4,560,000

6,470,000

N/A

N/A

4,020,000

4,800,000

3,550,000

1,460,000

3,410,000

4,160,000

N/A

N/A

8,250,000

7,700,000

N/A

N/A

4,440,000

2,860,000

2,790,000

2,790,000

3,690,000

3,880,000

Corn acres fertilized in
the spring with any
fertilizer. This includes
split applications and
spring only acres
Corn acres fertilized
only in the spring with
any nitrogen fertilizer
Corn acres fertilized in
the spring with
nitrification inhibitors

FERTILIZER APPLICATION STRATEGIES (Timing of Applications)
Survey results show that 31% of corn acres were fertilized only in the fall or winter. Twenty-six percent of corn acres
were fertilized only in the spring, and 43% of acres were fertilized in the fall and spring (split-application technique).

Timing of Fertilizer
Applications
NASS Corn Planted Acres
Acres fertilized only in the fall
Acres fertilized in the spring and fall
Acres fertilized only in the spring

2021 corn crop 2023 corn crop
11,000,000
2,740,000
3,820,000
4,440,000

11,200,000
3,500,000
4,840,000
2,860,000

Illinois
Released July 31, 2024

Nutrient Loss Reduction Strategy
Survey

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 790,000 acres of soybeans and 550,000 acres of corn following a cover crop in 2023.
A cover crop is defined as crops including grasses, legumes and forbs planted for conservation purposes, including
erosion control, improving soil structure, moisture, and nutrient content, increasing beneficial soil biota, or providing
habitat for insects, pollinators and wildlife.

Cover Crop Practices

Acres

2023 corn acres planted after cover crops
2023 soybean acres planted after cover crops
2023 total cover crops

550,000
790,000
1,440,000

2021 corn acres planted after cover crops
2021 soybean acres planted after cover crops
2021 total cover crops

450,000
890,000
1,390,000

Corn / Soybean acres planted to cover crops after the 2019 crop season on tiled ground.

930,000

Corn / Soybean acres planted to cover crops after the 2019 crop season on non-tiled ground.

480,000

Corn / Soybean acres planted to cover crops after the 2017 crop season on tiled ground.
Corn / Soybean acres planted to cover crops after the 2017 crop season on non-tiled ground.

290,000
420,000

Corn / Soybean acres planted to cover crops after the 2015 crop season on tiled ground.
Corn / Soybean acres planted to cover crops after the 2015 crop season on non-tiled ground.

490,000
630,000

Corn / Soybean acres planted to cover crops after the 2011 crop season on tiled ground.
Corn / Soybean acres planted to cover crops after the 2011 crop season on non-tiled ground.

220,000
380,000

Illinois
Released July 31, 2024

Nutrient Loss Reduction Strategy
Survey

The NASS survey included a series of general knowledge questions about the Nutrient Loss Reduction Strategy and Best
Management Practices (BMP’s).
NOTE: While the reference year for the most recent survey was the 2023 crop season, the survey questions were asked
to producers in 2024. And on the previous survey, the general knowledge questions were asked to producers in early
2022.

General Knowledge Questions
Knowledge in 2024

Not at all
Slightly
Somewhat
Very
Knowledgeable
knowledgeable knowledgeable knowledgeable
knowledgeable
Percent of Respondents

Nutrient Loss Reduction
Strategy

22.2%

29.6%

28.4%

13.8%

6.0%

MRTN strategy

18.5%

22.5%

33.0%

16.7%

9.3%

Wood chip bioreactors

61.3%

20.2%

12.1%

4.3%

2.1%

Constructed Wetlands

36.5%

27.1%

18.8%

14.4%

3.2%

Cover crop management

14.3%

25.4%

31.3%

18.9%

10.1%

Saturated Buffers

39.0%

26.1%

21.5%

10.1%

3.3%

Knowledge in 2022

Not at all
Slightly
Somewhat
Very
Knowledgeable
knowledgeable knowledgeable knowledgeable
knowledgeable
Percent of Respondents

Nutrient Loss Reduction
Strategy

20.3%

24.8%

36.7%

15.7%

2.5%

MRTN strategy

16.2%

14.9%

37.9%

25.0%

6.0%

Wood chip bioreactors

68.6%

14.7%

11.1%

4.8%

0.8%

Constructed Wetlands

35.5%

32.3%

21.7%

8.2%

2.3%

Cover crop management

15.9%

20.6%

35.3%

22.2%

6.0%

Saturated Buffers

33.8%

23.5%

25.4%

14.3%

3.0%

Illinois
Released July 31, 2024

Appendix A (survey questionnaire)

Nutrient Loss Reduction Strategy
Survey

Illinois
Released July 31, 2024

Nutrient Loss Reduction Strategy
Survey

Illinois
Released July 31, 2024

Nutrient Loss Reduction Strategy
Survey

Illinois
Released July 31, 2024

Nutrient Loss Reduction Strategy
Survey

Illinois
Released July 31, 2024

Nutrient Loss Reduction Strategy
Survey

Appendix B (cover letter and MRTN map)

February 2024
As the Chairman and Illinois Corn Growers’ representative on the Illinois Nutrient Research and Education Council
(NREC), I want to congratulate you for being selected to provide important information on behalf of Illinois farmers.
By way of background, the Illinois Nutrient Loss Reduction Strategy (NLRS) was developed by the Illinois Environmental
Protection Agency (IEPA), the Illinois Department of Agriculture (IDOA), and a multi-stakeholder Policy Working Group
(PWG). The initial NLRS was released in July 2015 and is a framework for leveraging existing programs to optimize
nutrient loss reduction while promoting collaboration, research, and innovation among the private sector, academia,
non-profits, wastewater treatment agencies, the agricultural sector, and state and local government.
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. 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.
The NLRS PWG is expected to report its progress to the public every two years via a Biennial Report, the first of which
was released in July 2017, followed by additional reports in November 2019, September 2021, and November 2023. An
important part of the Biennial Report is the attached National Agricultural Statistics Service (NASS) survey that can help
demonstrate implementation of various nutrient reduction best management practices (BMPs) on the land in a
statistically valid manner over a long period of time. In addition to funding important nutrient research, NREC also
prioritizes tracking the adoption and implementation of BMPs and provides the funding for the NLRS NASS survey on

Without the NASS survey, the full story of Illinois farmers’ efforts across
the state to improve water quality cannot accurately be told.
behalf of Illinois farmers.

Illinois farmers have been making tremendous strides at voluntarily implementing BMPs that make sense for both their
farms and the environment. Please take a few minutes to document your own progress toward the NLRS goals. Thank
you for your time and attention to this priority issue for Illinois agriculture.
For more information on the NLRS, see http://tiny.cc/Illinois-NLRS
Sincerely,

Don Guinnip
Chairman, Illinois Nutrient Research and Education Council

Illinois
Released July 31, 2024

Nutrient Loss Reduction Strategy
Survey

Please utilize this map and chart to answer Question 1 under Section 2: Nutrient Management.
Maximum Return to Nitrogen (MRTN) is the nitrogen rate where the economic net return to N application is maximized.
The MRTN rates below are calculated based on an extensive network of trials conducted across Illinois and prevailing
prices for N fertilizer and corn. The maximum rates shown are near the upper end of MRTN guideline rates, calculated
using corn prices (from spring 2023) of $6.00 to $6.50 per bushel and N prices of $0.60 to $1.00 per unit (lb. of actual N.)
The corn nitrogen rate calculator website is available at the following URL: https://www.cornnratecalc.org/

Northern Illinois

Central Illinois

Southern Illinois
Region

Crop rotation

Northern Illinois

Corn following soybean
Corn following corn
Corn following soybean
Corn following corn
Corn following soybean
Corn following corn

Central Illinois
Southern Illinois

Maximum rate (lb. N), 2023
180
205
185
200
200
200