69th SWCS International Annual Conference July 27-30, 2014 Lombard, IL

1. Garnering Local Buy-In:
SWAT Modeling of an Agricultural Watershed
Pat Conrad
Emmons & Olivier Resources
69th SWCS International
Annual Conference

2. Acknowledgements
Funding and data provided by:
SWAT Modelers:
Jason Ulrich - Emmons & Olivier Resources
James Almendinger - Science Museum of Minnesota/Emmons & Olivier
Resources
Brian Green - MPCA
Nick Gervino – MPCA
Natalie Siderius – Whitewater River Watershed Project Farmer-led Council
Sheila Harmes – Whitewater River Watershed Project

3. Whitewater River Watershed

4. Whitewater Watershed History: Farming
• Treaty of 1851
• Wheat
farming until
1878
• Flooding due
to landuse
1900

5. Whitewater Watershed History: Erosion
• 1920’s
Abandonment of
Elba and
Whitewater Falls
• 1930’s Government
buy-out for
conservation land

6. Whitewater Watershed History:
Conservation
• 2,700 Acre
Whitewater State
Park
• Conservation
Practices gaining
hold
• Whitewater River
Watershed Project

7. Whitewater Watershed Today
Whitewater River Watershed Project
• Forest Stewardship Plans
• Workshops and field days
• Nutrient and manure management planning
• Customized GIS mapping
• Neighborhood meetings
• One on one contacts with watershed
residents
• Newsletters & Brochures
**Farmer-Led Council – Advisory Board **

8. MN Watershed Assessment
10 Year Cycle
Monitoring &
Assessment
Watershed
Restoration &
Protection
Implementation

9. Watershed Assessment Findings
Multiple Impaired Stream
Reaches
Bacteria
Turbidity
Nitrate
TMDL Steps
Watershed Characterization
Impairment Status
Data Gaps and Monitoring Report
Source Assessment
Load Allocation
Set Targets
Implementation Strategies

10. Farmer-Led Council Meetings
Objectives
• Introduce SWAT modeling
• Review input parameters
• Determine scenarios to
evaluate
• Present results

11. SWAT Modeling
All models are wrong,
but some are useful
– George E.P. Box

12. Relative crop areas: 2007-11 averages
Whitewater
Garvin
Mississippi

13. Cropland Rotations
Continuous
Corn
24%
Corn/
Soybean
47%
Corn/
Alfalfa
17%
Sweet Corn/
Soybean
7%
Corn/ Peas-
Oats
5%

14. FLC Input: Tillage Practices
• Changed all disk operations to a shallow field cultivator
• When soybeans follow Corn, chisel plowing is done in
fall, not spring
• Chisel (not moldboard) plow in the fall of the last year of
alfalfa
• Current no-till occurs in corn-soybean rotations, where
soybeans are no-till planted into corn stubble. In
contrast, Corn is not no-till planted into bean stubble
• After no-till planting of soybeans, the field is "rolled" to
smooth the surface a bit and improve soil-seed contact
• No-till is more common on the sandier soils within the
watershed

15. • In corn soybean rotation, all fertilizer is applied in the corn
year, none in soybean year
• For nitrogen, the application rate is 200 lb N/acre for corn
• In corn soybean rotation, allow 40 lb N/acre credit for
soybeans the previous year, so add a total of 160 lb
N/acre more in the corn year
• Apply mostly as urea (46-0-0), and rest with starter
fertilizer
• 300 lbs of 46-0-0 gives 138 lbs N/acre
• Add enough starter fertilizer to get N up to 160 lb/acre
FLC Input: Fertilization Practices

16. • Corn stalks are removed (bailed) after harvest for
bedding material.
• Common cover crops: winter grains are used rather than
oats: winter wheat, winter rye, or triticale.
• Cover crops ONLY after crops that are harvested early,
like sweet corn, peas, and corn silage.
FLC Input: Cover Practices

17. Existing BMPs – Ponds and
Grassed Waterways

18. Scenario Selection
Appropriately sited
Acknowledge local
conditions
Footprint – loss of land
Cost
Scale of adoption

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23. Whitewater Watershed Today
• Voluntary Program
• Farm-field certification:
o Physical field characteristics
o Nutrient management
o Tillage management
o Pest management
o Irrigation and drainage management
o Conservation practices
• Regulatory “certainty” for 10 years
http://www.mda.state.mn.us/protectin
g/waterprotection/awqcprogram.aspx