Garnering Local Buy-In:SWAT Modeling of an Agricultural Watershed

Pat ConradEmmons & Olivier Resources

69th SWCS International Annual Conference

Acknowledgements

Funding and data provided by:

SWAT Modelers: Jason Ulrich - Emmons & Olivier ResourcesJames Almendinger - Science Museum of Minnesota/Emmons & Olivier ResourcesBrian Green - MPCANick Gervino – MPCANatalie Siderius – Whitewater River Watershed Project Farmer-led CouncilSheila Harmes – Whitewater River Watershed Project

Whitewater River Watershed

Whitewater Watershed History: Farming

• Treaty of 1851

• Wheat

farming until

1878

• Flooding due

to landuse

1900

Whitewater Watershed History: Erosion

• 1920’s

Abandonment of

Elba and

Whitewater Falls

• 1930’s Government

buy-out for

conservation land

Whitewater Watershed History: Conservation

• 2,700 Acre

Whitewater State

Park

• Conservation

Practices gaining

hold

• Whitewater River

Watershed Project

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 **

MN Watershed Assessment

10 Year Cycle

Monitoring & Assessment

Watershed Restoration &

ProtectionImplementation

Watershed Assessment Findings

Multiple Impaired Stream Reaches

BacteriaTurbidityNitrate

TMDL StepsWatershed CharacterizationImpairment StatusData Gaps and Monitoring ReportSource AssessmentLoad Allocation Set TargetsImplementation Strategies

Farmer-Led Council Meetings

Objectives• Introduce SWAT modeling

• Review input parameters

• Determine scenarios to

evaluate

• Present results

SWAT Modeling

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

Relative crop areas: 2007-11 averages

Whitewater

Garvin

Mississippi

Cropland Rotations

Continuous Corn24%

Corn/ Soybean

47%

Corn/ Alfalfa17%

Sweet Corn/ Soybean

7%

Corn/ Peas-Oats5%

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

• 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 lbN/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

• 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

Existing BMPs – Ponds and Grassed Waterways

Scenario Selection

Appropriately sited

Acknowledge local conditions

Footprint – loss of land

Cost

Scale of adoption

*

*

*

*

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