Nutrient Loss Reduction Strategy Survey Results (Illinois)

Illinois
Nutrient Loss Reduction Strategy Survey
Released July 6, 2020

BACKGROUND AND PURPOSE OF SURVEY
The state of Illinois developed a long-range plan, called the Nutrient Loss Reduction Strategy (NLRS), to reduce
loss of nutrients from agricultural fields (non-point sources) and also to address urban runoff (point sources).
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, in order 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 and measure those
same cultural practices for the 2015 crop season. The survey has been repeated to gather updated statistics
for 2017 and 2019.
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 statisticians would also like to thank all of the producers that responded to the survey.
SURVEY METHODOLOGY


SAMPLING: NASS staff drew a sample of 1,097 Illinois farms with at least 100 acres of cropland and also less than
5,000 acres of cropland.


DATA COLLECTION: NASS mailed questionnaires and return envelopes to producers in January 2020. A second
mailing was sent to non-respondents in early February. Following the second mailing, field enumerators phoned
the remaining non-respondents in mid-April.
REFERENCE YEAR: The 2019 crop season was the reference year for nearly all of the survey questions. The
General Knowledge questions are referenced to the time of the interview, in early 2020.

1

NITROGEN MANAGEMENT
Many producers are using some type of professional recommendations as they decide how much nitrogen to
apply on their corn acres. The NASS survey results show that producers used the MRTN (Maximum Return To
Nitrogen) strategy to help determine the amount of nitrogen they would apply to one-third of their 2019 corn
acres. In addition to the MRTN strategy, producers used other industry-recommended techniques on 70% of
their corn acres.
NOTE: Many producers considered more than one strategy before finalizing their decisions for nitrogen
applications. So two or more strategies could have been considered before applying nitrogen to some acres of
corn in 2019. Therefore, the sum of percentages in the table below is greater than 100%.

Nitrogen Management
Strategy
NASS corn planted acres
Acres where an MRTN (Maximum
Return To Nitrogen) strategy was
used to determine application rates
Other Industry-approved technique
acres

2

Acres in
2011

Acres in
2015

Acres in
2017

Acres in 2019

12,600,000
8,820,000
or 70% of
planted
acres

11,700,000
9,430,000
or 81% of
planted
acres

11,200,000
3,730,000
or 33% of
planted
acres
7,750,000 or
69% of
planted
acres

10,500,000
3,700,000 or 35%
or planted acres

Not asked

Not asked

7,390,000 or 70%
of planted acres

FERTILIZER APPLICATION STRATEGIES (Nitrification Inhibitors): The NASS survey showed that 14% of the 2019
corn acres, that are tiled, were fertilized in the fall or winter with a nitrification inhibitor. For non-tiled acres
that percentage is 5%.

Fertilizer Application
Strategies for corn on
tiled acres
Acres of corn planted
Fall / Winter nitrogen was
applied with a nitrification
inhibitor
Spring nitrogen was applied
with a nitrification inhibitor

Acres in
2011

Acres in
2015

Acres in 2017

Acres in 2019

12,600,000 11,700,000

11,200,000

10,500,000

3,240,000
or 26%

2,970,000
or 25%

3,550,000 or 32%

1,460,000 or 14%

Not asked

Not asked

2,790,000 or 25%

2,220,000 or 21%

Producers also used nitrification inhibitors when applying fertilizer in the spring. The NASS survey shows that
21% of corn acres on tiled ground were fertilized in the spring with a nitrification inhibitor and 20% of corn
acres on non-tiled ground were fertilized in the spring with a nitrification inhibitor.

Fertilizer Application
Strategies for corn on
non-tiled acres
Acres of corn planted

Acres in
2011

Acres in
2015

Acres in 2017

Acres in 2019

12,600,000 11,700,000

11,200,000

10,500,000

Fall / Winter nitrogen was
applied with a nitrification
inhibitor

Not asked

Not asked 1,040,000 or 9%

540,000 or 5%

Spring nitrogen was applied
with a nitrification inhibitor

Not asked

Not asked 1,020,000 or 9%

2,070,000 or 20%

3

FERTILIZER APPLICATION STRATEGIES (Timing of Applications)
For the timing of fertilizer applications, the Nutrient Loss Reduction Strategy (NLRS) recommends several
specific strategies. The NASS survey asked producers about which of those strategies they used, if any, in
preparation for the 2019 corn crop.
Strategy 1 – Fall and Winter N (nitrogen) applied was less than 50% of total nitrogen applications.
Strategy 2 – Fall and Winter N was 0% of total nitrogen (all spring applications).
Strategy 3 - Less than 50% of N applied in Fall and Winter, with remaining nitrogen applications split between
pre-plant and side-dress applications.

Fertilizer Application
Strategies for corn on tiled
acres
Acres of corn planted
STRATEGY 1 - Fall / Winter N was 50%
or less of total N
STRATEGY 2 - Fall / Winter N was 0% of
total N (all Spring applications)
STRATEGY 3 - Less than 50% FALL /
WINTER applications, with remaining
nitrogen applications split between
pre-plant and side-dress applications

Acres in
2011

Acres in
2015

Acres in 2017

Acres in 2019

12,600,000 11,700,000
940,000
950,000
or 7%
or 8%
2,480,000 2,660,000
or 20%
or 23%

11,200,000
780,000 or
7%
1,850,000
or 17%

10,500,000

1,730,000
or 14%

2,220,000
or 19%

1,790,000 or
16%

330,000 or 3%
1,720,000 or
16%
1,930,000 or
18%

Those same questions were also asked about corn on non-tiled acres. Those results are presented in the table
below.

Fertilizer Application Strategies for corn
on non-tiled acres
Acres of corn planted
STRATEGY 1 - Fall / Winter nitrogen was 50% or less of
total nitrogen
STRATEGY 2 - Fall / Winter nitrogen was 0% of total
nitrogen (all Spring applications)
STRATEGY 3 - Less than 50% FALL / WINTER applications,
with remaining nitrogen applications split between preplant and side-dress applications

4

Acres in 2017

Acres in 2019

11,200,000

10,500,000

340,000 or 3%

110,000 or 1%

1,250,000 or 11%

990,000 or 9%

930,000 or 8%

740,000 or 7%

PHOSPHOROUS
Since 2011, many producers have reduced the amount of phosphorous they apply on their cropland. NASS
survey results show that producers made those reductions on 7.4 million acres of tiled cropland and 3.8
million acres of non-tiled cropland.
Also, many producers have changed their phosphorous application methods from broadcast to subsurface, or
banding. The NASS survey shows that those changes were made on 1.44 million tiled acres and 870,000 nontiled acres.
2017
Acres

Reductions in phosphorus applications
Tiled acres
Non-tiled acres

Tiled acres
Non-tiled acres

Acres where phosphorus application rates were reduced
since 2011
Acres where phosphorus application rates were reduced
since 2011
Acres where placement of phosphorus applications were
moved from broadcast to subsurface or banding
Acres where placement of phosphorus applications were
moved from broadcast to subsurface or banding

2019
acres

4,440,000 7,410,000
2,150,000 3,800,000

1,530,000 1,440,000
280,000

870,000

When asked about the reasons for reducing phosphorous applications, producers gave the responses below:
 The Illinois Agronomy Handbook removal rates were updated was cited as the reason for phosphorous
reductions on nearly 4.5 million acres.
 Soil test results were cited as the reason for reductions on nearly 9.5 million acres.
 Other reasons, including cost, were cited as reasons for reductions on just over 5 million acres.
NOTE: The questionnaire allowed for producers to cite several reasons as evidence to reduce phosphorous
applications on the same acres.

Reasons for reducing phosphorus applications
The Illinois Agronomy Handbook removal rates for phosphorus were updated
Soil test information
Other reasons, including cost

2017
Acres
2,390,000
4,520,000
2,420,000

2019
Acres
4,460,000
9,470,000
5,030,000

5

COVER CROPS
The NASS survey included questions on seeding of cover crops, in 2019, on both tiled and non-tiled acres of corn and
soybeans. The questions were phrased to capture cover crops seeded into standing 2019 crops, or after the 2019 crop
was harvested.
Results show that farmers seeded 930,000 acres of cover crops on tiled acres and 480,000 acres of cover crops on nontiled acres.

Cover Crop questions (tiled and non-tiled acres)

6

Acres

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

930,000
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

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 2019 crop season, the survey questions were asked
to producers in 2020. And on the previous survey, the general knowledge questions were asked to producers in early
2019.

General Knowledge Questions
Percent of
Farms
reporting
in 2020
Nutrient Loss
Reduction
Strategy
MRTN
strategy
Wood chip
bioreactors
Constructed
Wetlands
Cover crop
management

Percent of
Farms
reporting
in 2019
Nutrient Loss
Reduction
Strategy
MRTN
Strategy
Bioreactors
Constructed
Wetlands
Cover Crops
Management

Not at all
Slightly
Somewhat
Knowledgeable
knowledgeable knowledgeable knowledgeable

Very
knowledgeable

26.9

29.9

20.7

10.7

11.8

30.2

29.0

17.6

14.7

8.5

54.7

17.2

14.4

11.5

2.2

42.1

20.5

16.5

17.9

3.0

9.1

24.7

27.7

26.1

12.4

Not at all
Slightly
Somewhat
Knowledgeable
knowledgeable knowledgeable knowledgeable

Very
knowledgeable

21.0

27.0

38.4

11.6

2.0

20.3

33.5

25.5

14.1

6.6

53.8

23.0

15.0

5.5

2.7

19.7

29.6

38.0

10.2

2.5

15.2

16.7

35.5

28.4

4.2

7