Koepke Farm Koepk Farms, Inc. s, Inc. All monitoring began on - - PowerPoint PPT Presentation

1/9/2012 1

Sediment Loss at Koepke Farms, Inc.

Koepk Koepke Farm Farms, Inc. s, Inc.

Surface and Tile Water Monitoring

• All monitoring began on June 1, 2005
• KP1: Tile monitoring site
• The East basin
• 81 acres
• Monitoring ended October 2009
• Separated from other sites by a drainage ditch
• KP2: Tile monitoring site
• The West basin
• 28 acres
• Monitoring ended October 2009
• KP3: Surface monitoring site
• The West basin
• 6.1 acres
• Monitoring ended September 2008

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Surface and Tile Water Monitoring

• The contributing area for the two tile line

sites were influenced by a fluctuating water table that extended beyond the surface topographic boundaries

• Calculating yield for tile sites was not

possible; exact area unknown

• Koepke Farms has hydric soils, formed

under saturated conditions for periods long enough to create anaerobic conditions

• Drain tile was installed to increase crop

production

• Due to poorly drained soils, dense

glacial material, and a seasonally high water table

Koepke Koepke Far Farms, Inc Inc.

Koepke Water Budget

• All data is based on the definition of a field year (FY):
• 12‐month period from Oct 1 through Sept 30 of the following year
• Allows water monitoring activities to coincide with crop production cycle
• Harvest after Sept is tied to the previous field year, but activities (tillage,

fertilizer, manure, etc) done after harvest are for the following year’s crop

• Precipitation is referred to as either frozen or non‐frozen
• All frozen precipitation was converted to its liquid

equivalent for analysis consistency

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• FY06 and FY09 had lower than average precipitation
• FY07 and FY08 had higher than average precipitation
• Surface water runoff ranged from 5% ‐ 16% of annual

precipitation.

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5 10 15 20 25 30 35 40 45 50

FY2006 FY2007 FY2008 FY2009*

Precipitation and Runoff, in Inches

Yearly Precipitation and Surface Runoff Koepke Farm, Oconomowoc, WI

Frozen Precip. (L.E.) Non‐frozen Precip. KP3 Runoff 5% 5% 16%

30‐yr Avg. Precipitation (33.9 inches)

Percent of precipitation that ran off KP3 FY2006 FY2007 FY2008 FY2009

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Water Quality Values in Concentrations ‐ Loads – Yields

Koepke Koepke Far Farms, Inc Inc.

• Discovery Farms water quality data provides both the concentration
• f various constituents (sediment, phosphorus, nitrogen, etc.) and

volume of runoff for individual runoff events.

• Concentrations are reported in milligrams/liter (mg/L) or parts per

million (ppm) and used to describe the amount or mass of a constituent per volume of sample.

• Concentrations alone cannot be used to describe agricultural runoff

losses because they don’t take into account the total volume of water that the sample represents.

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Water Quality Values in Concentrations – Loads ‐ Yields

Koepke Koepke Far Farms, Inc Inc.

• Combining concentrations with total water volume that a sample

represents provides the total loss or load derived from agricultural landscapes. – Loads are the total mass of a constituent per volume of runoff and are usually reported in pounds or tons.

• Using loads alone to compare farm fields or basins can be misleading

because loads do not take into account the size of the field or basin.

• Yields are used to compare multiple fields or basins and are reported as

pounds/acre or tons/acre. Yield is calculated by taking the total loss or load and dividing by the contributing area (field/basin size).

• Yield normalizes data and allows for acre to acre comparisons.

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Water Quality Values in Concentrations – Loads ‐ Yields

Due to fluctuating water table elevations, the exact land acreage drained by the tile sites (KP1, KP2) could not be determined. Thus, flow values, sediment and/or nutrient losses reported for the tile sites are identified as volumes (millions of gallons), concentrations (milligrams / liter), or loads for each field year. Since the exact land acreage drained by the surface site (KP3) was known, runoff values, sediment and/ or nutrient losses are reported as yield measurements (inches / acre or pounds / acre) for each field year.

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Cropping Practices

• Both basins were managed under a no‐till planting system with different

crop rotations

• In the east basin, alfalfa was chemically killed in the spring of 2007 a few

days prior to planting corn

• Manure was surface applied to corn acres in either late fall or spring

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Basin East - KP1 West - KP2/KP3 2005 2006 2007 2008 2009 2005 2006 2007 2008 2009 Crop Alfalfa Alfalfa Corn grain Corn silage Soybean Corn silage Corn grain Soybean Corn silage Alfalfa

KP1 and KP2 = Tile Site KP3 = Surface Site

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Surface Sediment Loss: Yields

• The average sediment loss for the surface basin KP3 during the monitoring

period was 172 lbs/acre/year

• It is low due to the no‐till cropping system and tile lines
• FY06 had a total surface sediment loss of 40 lbs/acre
• Sediment losses occurred only in March and April
• FY07 had a total surface sediment loss of 216 lbs/acre
• 89% of the total sediment lost came from one storm event on Oct. 4
• FY08 had a total surface sediment loss of 260 lbs/acre
• 93% of the total sediment lost came from one storm event dropping 7.3”

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See graphs – next 2 slides

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50 100 150 200 250 300 FY2006 FY2007 FY2008 Sediment yield (lbs/acre)

KP3 Annual Sediment Loss – Surface Basin

Frozen Non‐Frozen

Average sediment loss (surface basin) through study period = 172 lbs / ac / yr Attributed to no‐till cropping system and tile drainage

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Koepke Koepke Far Farms, Inc Inc.

Surface sediment loss on this farm was driven by large single events. Approx 90% of 07 and 08 sediment from a single event storm each year.

50 100 150 200 250

Sediment yield (lbs/acre)

KP3 Monthly Sediment Loss – Surface Basin

FY2006 FY2007 FY2008

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Tile Sediment Loss: Concentrations and Loads

• Sediment yields were not calculated because the contributing area for the tile drainage

system could not accurately be determined.

• High sediment concentrations were observed in both tile systems during late fall,

winter and early spring

• Total sediment loads were typically higher under corn and soybeans than alfalfa
• Field year accounting method attributes soil loss between fall harvest and spring

planting to the next year’s crop.

• Sediment loads shown for given crop can be misleading
• Example: Largest sediment concentration was observed at KP2 in October 4, 2006.
• Although this event is placed under the soybean crop grown in 2007, the sediment

loss should be linked to the corn grown in 2006

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Tile Sediment Loss: Concentrations and Loads

Koepke Koepke Far Farms, Inc Inc.

FY2005* FY2006 FY2007 FY2008 FY2009 KP1 Alfalfa Alfalfa Corn grain Corn silage Soybean Concentration Range (Avg.) 5 mg/L (5 mg/L) <2 - 92 mg/L (21 mg/L) <2 - 151 mg/L (20 mg/L) <1 – 168 mg/L (37 mg/L) <2 – 10 mg/L (5 mg/L) Load 1.6 lbs 650 lbs 1458 lbs 3106 lbs

• KP2

Corn silage Corn grain Soybean Corn silage Alfalfa Concentration Range (Avg.) 3 – 4 mg/L (3 mg/L) <2 – 116 mg/L (25 mg/L) <2 – 362 mg/L (34 mg/L) <1 – 158 mg/L (31 mg/L) <2 – 9 mg/L (6 mg/L) Load 1.9 lbs 893 lbs 1729 lbs 1817 lbs

• *Annotates partial year of sampling

Annotates only monthly base flow sampling

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Koepke Koepke Far Farms, Inc Inc.

200 400 600 800 1000 1200 1400 Total sediment load (lbs)

Monthly Total Sediment Loads – Tile Basins

FY2006 FY2007 FY2008

KP1 KP2

Tile Sediment Loss: Timing was more consistent than surface runoff, and more substantial during frozen ground conditions than non frozen ground. Highest sediment loss months for both tile sites were Feb and June.

37% 63%

Total Tile Sediment Loss by Period

Frozen Non‐Frozen

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Sediment Loss During Frozen vs. Non‐Frozen Ground Time Period

• 2. During frozen ground

Surface sediment loss = 3% of yr total Tile sediment loss = 37% of yr total ** ** Macropore flow during frozen conditions

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• 1. Sediment loss occurs more frequently

when the soil is not frozen.

3% 97%

Total Surface Sediment Loss by Period

Frozen Non‐Frozen

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Conclusions

Koepke Koepke Far Farms, Inc Inc.

• The average sediment loss for the surface basin (KP3) during

the monitoring period was 172 pounds/acre/year.

• Relatively small amount of surface sediment loss occurred

each year during snowmelt and subsequent spring rains in March and April

– Majority associated with single storm events. Over a 3‐year period, 84% of the total sediment loss was from two storm events.

• The no‐till farming system at Koepke Farms limits the

transport mechanism of soil loss ‐ retains water and allows for infiltration into the soil, thus reducing sediment loss.

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Conclusions

Koepke Koepke Far Farms, Inc Inc.

• The contributing area for the tile drainage system could not

accurately be determined, therefore sediment yields were not generated from the water quality data. Raw water sample analysis concentrations and loads were used to identify trends in water quality data.

• Analysis of tile sediment concentrations show that high

sediment concentrations were observed in both tile systems during late fall, winter and early spring as compared to

• summer. The highest sediment loss months for both tile sites

were February and June.

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Conclusions

Koepke Koepke Far Farms, Inc Inc.

• Tile sediment loads were typically high under corn and

soybeans as compared to alfalfa.

• Sediment loss timing was very different between surface and

tile.

• During frozen ground conditions, minimal sediment loss
• ccurred at the surface site (3%); whereas, more substantial

sediment loss occurred at the tile sites (37%).