This document discusses implementing a watershed approach to reducing nutrient losses from agricultural landscapes. It proposes looking at entire watershed systems, from fields to streams, to identify opportunities to decrease nutrient sources and transport and restore nutrient sinks. Priority practices are mapped based on landscape factors like soil drainage. Case studies demonstrate the approach, showing scenarios to achieve water quality goals through targeted placement of practices. Lessons from demonstration projects inform transferring the approach to other areas.

1. AN INNOVATIVE APPROACH TO
REDUCING NUTRIENT LOSSES FROM
AGRICULTURAL LANDSCAPES
THE WATERSHED APPROACH

2. The need for a new approach to agricultural
conservation
What is the watershed approach?
How do we implement the watershed
approach on the ground?
Case study: Matson Ditch, St. Joseph
River, IN
Lessons learned and transferability
SYMPOSIUM OUTLINE

3. Why Do We Need a New Approach to
Conservation?
• Growing awareness of problems associated with nitrogen
losses from agricultural landscapes.
• Reducing nitrogen losses requires a different approach to
agricultural conservation.
• Nitrogen moves primarily with subsurface flows
• Nitrogen-related water quality problems are invisible on
the farm but affect downstream communities at a regional
scale
• Past conservation efforts have been very successful in
reducing soil erosion (and phosphorus losses).
• But much more needs to be done to reduce phosphorus
losses from agricultural landscapes.

4. The Scale of the Solution Needs to Match the
Scale of the Problem
45% reduction in downstream loads
Signficant reductions in
stream N and P needed
to meet new nutrient
criteria
We need to treat the causes, not the
symptoms

5. How have these landscapes changed in the past 150
years?
What causes nutrient losses from Midwestern
landscapes?

6. LANDSCAPE
CHANGES
INCREASED
NUTRIENT
EXPORT

7. McLellan et al, in press

8. Ways to increase
nutrient losses

9. Decreased
nitrogen
transport
Decreased
nitrogen
transport
Decreased
nitrogen
sources
Increased
nitrogen
sinks
Ways to decrease
nutrient losses

10. Decrease N sources:
• Improve nutrient management
• Use extended rotations and/or conservation cover
• Use cover crops
Decrease N transport:
• Use cover crops
• Use conservation tillage (soil water storage)
• Use controlled drainage
• Use water storage structures in the landscape (ponds, wetlands
etc.)
Restore N sinks:
• Wet places + organic material + time = denitrification (N2 gas)
• Restore wetlands
• Create wetlands (add organics to wet places, or make organic-rich
places wet)
How do We Decrease N (or P) Loss From the
Landscape?
A SYSTEMS APPROACH AT
WATERSHED SCALE
Restoring sinks on 1-2% of the landscape can decrease
downstream nutrient loads by 45% (McLellan et al, in press)

11. THE WATERSHED APPROACH:
A SYSTEMIC AND STRATEGIC
APPROACH AT WATERSHED SCALE
Following the flow of water…surface and subsurface…
Reduce sources, reduce transport, restore sinks

12. Across the landscape from field to farm to
ditch/stream/lake

13. Use practices to reduce
and recycle nutrient
inputs within fields
Use practices within
and at the edge of
fields to capture flows
and prevent nutrient
losses
Use practices in riparian
areas, ditches and
streams to intercept and
treat nutrients lost from
fields
Identify potential practices all
along the flowpaths from
fields to ditches, streams and
rivers;
Target field-scale practices
(reduce, recycle) to areas
most vulnerable to nutrient
loss;
Target beyond-field
practices (trap and treat) to
locations where they
intercept the largest flows.

14. IMPLEMENTING THE
WATERSHED APPROACH
SCIENCE:
Identify priority
conservation
practices and
locations
SOCIAL/
ECONOMIC
INCENTIVES:
Encourage
producers to
adopt priority
practices at
priority locations
Systemic, strategic, solutions-oriented, community-focused

15. Decrease N sources:
• Improve nutrient management
• Use extended rotations and/or conservation cover
• Use cover crops
Decrease N transport:
• Use cover crops
• Use erosion control practices
• Use conservation tillage (soil water storage)
• Use water storage structures in the landscape (ponds, wetlands
etc.)
Restore N sinks:
• Wet places + organic material + time = denitrification (N2 gas)
• Restore wetlands
• Create wetlands (add organics to wet places, or make organic-rich
places wet)
The Scientific Heart of the Watershed
Approach
What are the sources of N?
How does N move across the
landscape?
Where can we restore sinks?

16. Steps in Watershed Analysis
• Look at watershed geology, soils, topography, nutrient
budgets
 Dominant sources and flowpaths
• How can we best avoid, control and treat nitrogen and
phosphorus along these flowpaths?
 Priority conservation practices
• Where is it (theoretically) possible to put these practices
in the landscape?
 Priority locations where the practices will do the
most good
• How many of what kinds of practices are needed to
achieve water quality goals?
 Conservation scenarios

17. Poorly Drained Soils Well Drained Soils
High relief (slopes > 5%) Farming on sloping lands in old
glacial landscapes, thin loess or
paleosols, high runoff potential
Farming on sloping lands
underlain by shallow bedrock or
sands, potential karst, baseflow-
dominated with high runoff
potential during storm events
Low relief (slopes < 5%) Dissected
(slopes 2<x<5% )
Non-dissected
(slopes < 2%)
Farming on sand plains,
floodplains, terraces, infiltration-
dominated system, high baseflow
Farming on
upland divides
and stepped
terraces, high
runoff potential
with tiling along
waterways
Farming on
hydric soils,
widespread
artificial
drainage
Agro-hydrologic analysis: geology, soils and
topography determine dominant flowpaths
Schilling et al, in review

18. Distribution of Different Types of Watersheds Across
the UMORB

19. Poorly Drained Soils Well Drained Soils
High relief (slopes > 5%) Grass waterways, contour filter
strips, terraces, ponds, riparian
buffers, cover crops
In-field source controls important,
riparian buffers, springs, seeps,
floodplain reconnection, in-stream
practices
Low relief (slopes < 5%) Dissected
(slopes 2<x<5% )
Non-dissected
(slopes < 2%)
In-field source controls important,
2-stage ditches, floodplain
reconnection, off-channel wetlands
Grass waterways,
filter strips,
ponds, cover
crops, riparian
buffers, wetlands,
bioreactors
Drainage
water
management,
treatment
wetlands,
bioreactors, 2-
stage ditches
Different Priority Practices for Different
Types of Watersheds

20. Practices to Reduce Nutrient Losses in
Surface Runoff
No-till Grass waterways Filter strips
Riparian buffers Ponds/basins Conservation cover

21. Controlled
drainage
Bioreactor
Treatment wetland Saturated buffers
Practices to Reduce Nutrient Loss in Tile
Drainage

22. Saturated buffers Stream diversion
Cover cropsNutrient management
Practices to address nutrient loss in subsurface
flow

23. WHAT WOULD THIS LOOK LIKE IN REAL
WATERSHEDS ACROSS THE MIDWEST?
Project goal: develop a set of watershed planning
resources to assist communities in meeting regional
water quality goals.
EDF-NRCS Watershed Planning Demonstration
Project
Watershed planning resources: new conservation
practices, new conservation planning tools, and
new conservation planning processes.

24. EDF PowerPoint Template
Title Slide
Project Collaborators
Toby Dogwiler, Winona State University
Adam Kiel and Keegan Kult, Iowa Soybean Association
Joe Magner, University of Minnesota
Linda Prokopy and Nick Babin, Purdue University
Keith Schilling and Calvin Wolter, IA-DNR
Doug Smith, USDA-ARS-NSERL
Mark Tomer and Sarah Porter, USDA-ARS-NLAE
The staffs of Dekalb SWCD (IN) and Winona SWCD (MN) and of NRCS
Field Offices in Dekalb County, IN, Floyd/Chickasaw Counties (IA) and
Olmsted/Winona Counties (MN).
Numerous producers in Beaver Creek (IA), Matson Ditch (IN) and Middle
Fork Whitewater (MN)
Funding Support
EDF gratefully acknowledges support provided through a Contribution
Agreement from NRCS, and grants from the Joyce Foundation and the
Walton Family Foundation.

25. Poorly Drained Soils Well Drained Soils
High relief (slopes > 5%) Farming on sloping lands in old
glacial landscapes, thin loess or
paleosols, high runoff potential
Farming on sloping lands
underlain by shallow bedrock or
sands, potential karst, baseflow-
dominated with high runoff
potential during storm events
Low relief (slopes < 5%) Dissected
(slopes 2<x<5% )
Non-dissected
(slopes < 2%)
Farming on sand plains,
floodplains, terraces, infiltration-
dominated system, high baseflow
Farming on
upland divides
and stepped
terraces, high
runoff potential
with tiling along
waterways
Farming on
hydric soils,
widespread
artificial
drainage
3 Demonstration Watersheds Representing 3
Different Types
Whitewater, MN
Beaver
Creek, IA
Matson
Ditch,
IN

26. MATSON DITCH
WATERSHED PLANNING DEMONSTRATION
PROJECT

27. Matson Ditch Watershed Planning Project
• Nutrient sources and flowpaths
• Priority conservation practices to address these
• Practice placement in the watershed
• Conservation scenarios to achieve 40% P reduction
goal
• Insights from social science
• Engaging partners
• Lessons learned

28. QUESTIONS?

29. POTENTIAL CONSERVATION PRACTICES FOR
MATSON DITCH
Innovative practices are highlighted; practices that are useful for
treating high flows are shown with an asterisk*.
Improved nutrient management
Conservation tillage
Cover crops
Blind inlets
Wetland restoration
Grass waterways
Ponds*
Nutrient removal wetlands
Stream diversions (off-channel storage) including gravel
pits*
Tile diversions/riparian bioreactors
Two-stage ditches*

33. PRACTICE COMPARISON TABLE
Practice Acres to achieve a
40% reduction
Reduction goal
achieved?
Practice lifetime
Nutrient
management
10,000 + NO Annual
No‐till 10,000 + NO Annual
Cover crops 10,000 + NO Annual
Extended rotations Annual
Blind inlets Every inlet + NEARLY
Grass waterways 730 acres ?
Ponds 200 acres ? Annual dredging
Nutrient removal
wetlands
450 acres ? 50 years
Stream diversions 20 acres ? Need to harvest
vegetation
Tile diversions with
slag
50 acres ? Need to clean out
gravel
Two stage ditches 5 acres ? Need to harvest
vegetation