Eating the
metaphorical
elephant:
Chris Hay, Iowa Soybean Association
Gary Feyereisen, USDA ARS
Reid Christianson, University of Illinois
Matt Helmers, Iowa State University
Meeting nitrogen reduction goals in the Upper Mississippi River
Basin
Photo: Ray in Manila

Source: USGS

NA NA
Source: Nancy N. Rabalais, LUMCON and R. Eugene Turner, LSU

Source: Nancy N. Rabalais, LUMCON and R. Eugene Turner, LSU
NA NA

Meeting nutrient reduction goals
will be a massive effort
Photo: Pete Markham

Source: USGS
Iowa
15%
Minnesota
6%
Illinois
15%

• Recommended in state NRS
• Literature
• Professional judgement
Implementation area

Scenarios
High
Medium
Low
Benchmark

Load reduction calculations
Individual practices
• Relative reductions e.g,
• Wetlands with average nitrate-N
reduction of 50% (IL, MN)
• Treating drainage area that is 8% of
row crop acres
• Nitrate-N load reduction is 4%
Stacked practices

• Economics
• Human dimensions
• Delivery capacity
Challenges/implications
Benchmark
45%

Slide courtesy of Gary Feyereisen

Slide courtesy of Gary Feyereisen

Slide courtesy of Gary Feyereisen

• Economics
• Human dimensions
• Delivery capacity
• Risk management
• Climate change
• Research needs
• Revolutionary change
Challenges/implications
Benchmark
45%

Photo: capt_tain Tom
• Meeting nutrient reduction goals
will be a massive effort with
many challenges
• No one practice or group of
practices will meet the goals—
mix of all practices needed
• Understanding the scale of the
challenge is a necessary step
toward meeting the challenge
In summary:
Photo: ISA