This document summarizes a study that used targeted conservation planning to identify opportunities for improving ecosystem services in an agricultural watershed. The Agricultural Conservation Planning Framework was used to assess field-level risks of runoff and nitrate leaching. Fields were then prioritized based on their combined biophysical risk and opportunity costs. This approach identified fields where conservation practices could reduce nutrient losses at low cost and high ecological benefit, optimizing environmental and economic outcomes. The results provide an example of how targeted conservation can be implemented in a watershed to meet nutrient reduction goals in a cost-effective manner.

1. Targeting for Diverse Ecosystem Service
Outcomes in an Agricultural Matrix
Emily Zimmerman1, Lisa Schulte Moore2, John Tyndall2
1Graduate Program in Sustainable Agriculture, Iowa State University
2Department of Natural Resources Ecology and Management, Iowa State University
Soil and Water Conservation Society
July 26th, 2016

2. Background
Photo credit: USDA NRCSPhoto credit: fishhawk/Flickr

3. Background
How do we do this?

4. Background
Targeted conservation is a spatially-coordinated approach to
implementing conservation practices (e.g., cover crops, buffers,
wetlands) on specific fields identified within a watershed as being
significant contributors to nutrient loads due to biophysical vulnerabilities
(Berry et al. 2005).
Catchments Drainage Slope Land Use
Agricultural
Pollution
Potential

5. Background
Data & ToolsResearch Policy
Targeted Conservation

6. Background
Data & ToolsResearch Policy
Targeted Conservation
Prior research has shown that relatively large reductions in nitrogen
loss at the watershed level can be achieved by coordinated placement
of conservation practices on relatively few, high-contributing fields.

7. Background
Data & ToolsResearch Policy
Targeted Conservation
Geospatial Tools
Agricultural Conservation Planning
Framework (ACPF)
Soil and Water Assessment Tool
(SWAT)
Agricultural Policy/Environmental
eXtender
Geospatial Data
High Resolution
Land Cover
Hillshade Soil Series

8. Background
Tools & DataResearch Policy
Targeted Conservation
Iowa Nutrient Reduction Strategy
is a science and technology-based
framework to assess and reduce point
and nonpoint surface nutrients to Iowa
surface waters in a scientific,
reasonable and cost effective manner.
“…in combination with targeted
practices designed to reduce loads
from nonpoint sources…”Photo credit: NOAA
41% reduction in N from NPS
29% reduction in P from NPS

9. Background
Tools & DataResearch Policy
Targeted Conservation
Iowa Nutrient Reduction Strategy
is a science and technology-based
framework to assess and reduce point
and nonpoint surface nutrients to Iowa
surface waters in a scientific,
reasonable and cost effective manner.
“…in combination with targeted
practices designed to reduce loads
from nonpoint sources…”Photo credit: NOAA
41% reduction in N from NPS
29% reduction in P from NPS

10. Primary Questions
How can opportunities and tradeoffs in biophysical vulnerability and
cost be identified in the watershed, and how might these opportunities
and tradeoffs be integrated into a spatially-targeted conservation
approach?

11. Study Location
Size: 33,937 acres
Dominant land use: +80% row-crop corn and
soybeans, pasture adjacent to perennial
streams
Outlet: Big Creek Lake, ~870 acres (Big Creek
State Park)
Big Creek State Park: 730,000 visitors per year
(Otto et al. 2012).
Listed on the U.S. EPA 303(d) list due to water
quality impairments (i.e., nonpoint source
nutrient, sediment, & E. coli) that originate in
upper watersheds.
Big Creek Watershed

12. Methods & Results
Agricultural Conservation Planning Framework (ACPF) is a GIS-based, landscape-
planning tool designed to identify vulnerable fields and to strategically place appropriate
conservation practices in those fields (Tomer et al. 2013).
ACPF Online: http://northcentralwater.org/acpf/
Input Layers Processes Outputs
Watershed boundary
3-m DEM
Field boundaries
Soils
6-year land-use
Qualitative data
Pre-characterization (e.g., terrain processing;
ID stream network & catchment)
Field Characterization (e.g., drainage
determination; runoff risk assessment)
Precision Conservation Practice Siting (e.g.,
contour filter strips; nutrient removal wetlands)
Watershed- & field-level
agricultural conservation
planning scenarios, with
strategically integrated
conservation practices

13. Methods & Results
Agricultural Conservation Planning Framework (ACPF) is a GIS-based, landscape-
planning tool designed to identify vulnerable fields and to strategically place appropriate
conservation practices in those fields (Tomer et al. 2013).
ACPF Online: http://northcentralwater.org/acpf/
Input Layers Processes Outputs
Watershed boundary
3-m DEM
Field boundaries
Soils
6-year land-use
Qualitative data
Pre-characterization (e.g., terrain processing;
ID stream network & catchment)
Field Characterization (e.g., drainage
determination; runoff risk assessment)
Precision Conservation Practice Siting (e.g.,
contour filter strips; nutrient removal wetlands)
Watershed- & field-level
agricultural conservation
planning scenarios, with
strategically integrated
conservation practices

14. Methods & Results
ACPF Runoff Risk Assessment: Prioritize fields where multiple erosion
control practices are most needed.
Close to stream Far from stream
High High Medium Low
Medium Medium Low Present
Low Low Present Present
SlopeSteepness
Proximity to Stream (Sediment Delivery Ratio)

15. Methods & Results
ACPF Runoff Risk Assessment Outcomes:
Runoff Risk Number of Fields
High 57
Medium 41
Low 32

16. Methods & Results
Building on ACPF Runoff Risk Assessment:
Runoff
Risk
Nitrate Leaching
Risk
Opportunity
Costs
Combined Biophysical Risk Opportunity Cost
Prioritization based on biophysical risk and opportunity costs

17. Methods & Results
Building on ACPF Runoff Risk Assessment:
Nitrate Leaching Risk
Selected only agricultural fields
Hydrologic Soil Classification (NRCS)
Fields sorted based on proportion of field
assigned a dual drainage classification,
indicating high probability of tile drainage
Nitrate Leaching Risk Number of Fields
High (40% fields) 182
Medium (40% fields) 182
Low (20% fields) 91

18. Methods & Results
Runoff Risk (SDR & Slope)
High Medium Low Present
High High High Medium Present
Medium High High Medium Present
Low Medium Medium Low Present
NitrateLeaching
Risk
Building on ACPF Runoff Risk Assessment:
Combined Biophysical Risk

19. Methods & Results
Building on ACPF Runoff Risk Assessment:
Combined Biophysical Risk
Biophysical Risk Number of Fields
High 42
Medium 58
Low 20

20. Methods & Results
Soil Unit CSR Acres Rating by Unit
Red 82 20 82*15=1230
Gray 92 40 92*10=920
White 79 40 79*60=4740
Weighted CSR = Σ(Rating by Unit)
Σ(Acres)
= 6890
100
= 69 CSR
Per acre rental rate = Weighted CSR * $3.10 = $213.59/acre
Field A: 100 acres
Building on ACPF Runoff Risk Assessment:
Opportunity Costs

21. Methods & Results
Building on ACPF Runoff Risk Assessment: Opportunity Costs
Average Opportunity
Cost per Acre:
$243.50

22. Methods & Results
Building on ACPF Runoff Risk Assessment: Biophysical Risk & Opportunity Costs
Runoff
Risk
Nitrate Leaching
Risk
Opportunity
Costs
Combined Biophysical Risk Opportunity Cost
Prioritization based on biophysical risk and opportunity costs

23. Methods & Results
Building on ACPF Runoff Risk Assessment: Biophysical Risk & Opportunity Costs
Combined Biophysical Risk
OpportunityCosts
High Medium Low Present
High Moderate Priority Low Priority Marginal Priority Not Priority
Medium High Priority Low Priority Low Priority Not Priority
Low Critical Priority High Priority Moderate Priority Not Priority
Critical Priority: Opportunity, Low cost, high biophysical risk
…
Marginal Priority: Tradeoff, High cost, low biophysical risk

24. Methods & Results
Building on ACPF Runoff Risk Assessment:
Biophysical Risk & Opportunity Costs
Critical Priority: Opportunity, Low cost, high biophysical risk
Marginal Priority: Tradeoff, High cost, low biophysical risk
Priority Number of Fields
Critical Priority 14
High Priority 44
Moderate Priority 19
Low Priority 33
Marginal Priority 2

25. Take Home Message & Conclusions
What we’re doing now: Targeted conservation
is being used to identify, spatially prioritize,
and treat fields with significant biophysical
vulnerabilities to meet nutrient reduction goals
set forth by state policies.
Economic costs are being calculated for
installing and managing conservation
practices.
Hypothetical Conservation Plan (ACPF)
20 wetland complexes (703 acres) 45,000 acres cover
crops, 66 saturated buffers (12.9 miles)
Removal of LT 2% cultivated acres
Estimated Nitrogen Reduction: 48%
Installation Costs: $6.85 million
Annual Costs: $3.54 million

26. Take Home Message & Conclusions
Where the opportunities are:
Targeted conservation has the potential to not only identify, spatially prioritize, and
treat fields with significant biophysical vulnerabilities, but to integrate opportunity
costs into prioritization as a way to prioritize and optimize for ‘win-win’ outcomes
that make ecological and economic sense.

27. Questions
Questions?
Emily Zimmerman, emilyz@iastate.edu
John Tyndall, jtyndall@iastate.edu
Lisa Schulte Moore, lschulte@iastate.edu
This research is generously funded by the Leopold Center for Sustainable Agriculture.

28. Extra Slides

29. Methods & Results
Agricultural Conservation Planning Framework (ACPF) is a GIS-based, landscape-
planning tool designed to identify vulnerable fields and to strategically place appropriate
conservation practices in those fields (Tomer et al. 2013).
A spreadsheet approach was used to calculate nitrogen reduction in each scenario
(Tomer et al. 2015). IA NRS cost tools were used to calculate costs for each scenario
(Bowman & Tyndall, unpublished).
Input Layers Processes Outputs
Watershed boundary
3-m DEM
Field boundaries
Soils
6-year land-use
Qualitative data
Pre-characterization (e.g., terrain processing;
ID stream network & catchment)
Field Characterization (e.g., drainage
determination; runoff risk assessment)
Precision Conservation Practice Siting (e.g.,
contour filter strips; nutrient removal wetlands)
Watershed- & field-level
agricultural conservation
planning scenarios, with
strategically integrated
conservation practices

30. Additional Methods, Spreadsheet
Field_ID LandUse Prop_Watershed Rot_Weight BMP_1 BMP_2 BMP_3 Prod
1 C/S Continuous Corn 0.20 1.05 0.70 0.50 1.00 0.07
2 Continuous Corn 0.15 1.10 0.70 0.50 1.00 0.05
3 C/S 0.30 1.00 1.00 0.50 0.70 0.11
4 Pasture 0.15 0.90 1.00 1.00 1.00 0.14
5 Pasture 0.10 0.90 1.00 1.00 1.00 0.09
6 C/S Continuous Corn 0.10 1.05 0.70 1.00 1.00 0.07
0.53
Hypothetical scenario results in 47% nitrate reduction.

31. Results
20 wetland complexes, located
in upper watershed. Selected
specifically for low wetland area
to drainage area ratio (LT 3%).
Removal of 703 acres (LT 2% of
watershed) from cultivation.
Treatment of GT 20,000 acres.
45,000 acres cover crops,
located on all acres growing corn
or soybeans. No land removed
from cultivation.
66 saturated buffers, extending
12.9 miles of stream reach.
Removal of 256 acres from
cultivation (LT 1% of watershed).
Treatment of 950+ acres.

32. Results
Conservation
Practice
Estimated N
Reduction Efficiency
Installation Costs Annual Costs
Big Creek
Watershed
Wetlands 50% $6,800,000 $625,670
Cover Crops 30% $0 $2,800,000
Saturated Buffers 90% $52,736 (+) $116,480 (+)
Land Removed from Cultivation 959 acres (LT 2%)
Estimated N Reduction 48%
Installation Costs $6,850,000
Annual Costs $3,540,000
For comparison, in 2014, Iowa spent $234,947,835 on conservation payments.

33. Additional Methods, Costs
Wetlands (20 wetlands, 703 acres) –
Installation cost: $9,963 x 703 acres = $6.8 million
Annual cost: $890 x 703 = $625,670
Cover Crops (45,000 acres) –
Annual cost: $62/acre x 45,000 acres = $2.8 million
Saturated Buffers (66 saturated buffers, 256 acres) –
Installation cost: $206/per acre x 256 acres = $52,736 (+)
Annual cost: (Riparian buffers), $455/per acre x 256 acres = $116,480 (+)
Installation Costs: $6.85 million
Annual Costs: $3.54 million
For comparison, in 2014, Iowa spent $234,947,835 on conservation payments.

34. Methods & Results
Combined Biophysical Risk
Runoff Risk (SDR & Slope)
Critical Very High High Present
High High High Medium Present
Medium High High Medium Present
Low Medium Medium Low Present
NitrateLeachingRisk
Where do opportunities and tradeoffs in vulnerability and cost exist in the watershed?
Opportunity Cost (Rental Rates)
Combined Biophysical Risk
OpportunityCosts
Critical Very High High Present
High 3 4 5 6
Medium 2 4 4 6
Low 1 2 3 6
1: Low cost, critical biophysical risk
…
5: High cost, high biophysical risk
Fields categorized as high, medium, and low cost using
weighted-CSR ratings from SSURGO data.
40% agricultural fields: High
40% agricultural fields: Medium
20% agricultural fields: Low