Nitrogen Losses at a Drainage Systems Scale

Bruce MontgomeryMN Department of Agriculture

Red Top Cooperators

UM Dept. of Soil, Water & Climate

Blue Earth Agronomics

Rob & Janice Meyer-Red Top Farms

University of Minnesota Extension

UM Dept of Biosystems and Ag Eng.

Brown Nicollet Environmental Health

And the BNC Water Quality Board

Why do producers error on the high side? “Research is only tested on garden size plots!”

Because most research is developed on small

plots under ideal conditions, many

farmers believe that University

recommendations will not work on production

scale operations

St. Peter Wellhead Protection Area

Community Water Supplies Impacted by Ag

0

2

4

6

8

10

12

14

Year

Nit

rate

-N (

mg

/l)

Well # 6

Well # 9

North Water Plant

South Water Plant

Trend Line

Key Project Goals: Red Top Farm Demonstration

Bridge the gap between UM water quality plot work and farm fields in terms of evaluating nitrogen and pesticide Best Management Practices (BMPs).

Characterize long-term water quantity and quality trends on a field scale using subsurface tile drainage systems.

Develop a demonstration site that is meaningful on a local and a regional scale.

Red Top is Located in Nicollet County, MN

Red Top Field Layout

West Field East Field

Monitoring Equipment at Red Top

Tile Peak Flow Hydrograph June 3 - 8, 2002Total Precip 4.67 in

WE RO 1.69 in EA RO 3.42 inWeir RO 2.47 in (53%) East Field 4.08 in (87%)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2-Jun 3-Jun 4-Jun 5-Jun 6-Jun 7-Jun 8-Jun 9-Jun 10-JunDate

Dis

ch

arg

e (

cfs

)

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Pre

cip

ita

tio

n (

inc

he

s/1

5 m

in)

WE Weir (6" Cement Mains) (Max drainage =0.44" in 24 hr)

EA Weir (8" Cement Mains) (Max Drainage = 0.95" in 24 hr)

East Field (8 to 12" Plastic Mains)(Max Drainage = 1.38" in 24 hr)

West Field (EA + WE)

Rainfall

Annual Drainage LossesRed Top Farm 1997-2002

0

5

10

15

20

1997 1998 1999 2000 2001 2002*

Growing Year (Note: 2002 is a partial year)

West Field (total) East Field

An

nu

al D

rain

ag

e L

oss

(In

ch

es)

On average, 7” of drainage or 25% of the annual water

budget is transported.

“Storm Events” account for the majority of the annual drainage

losses

0

2

4

6

8

10

12

14

1998 1999 2000 2001

BaseStorm

58% 74%

76%

An

nu

al D

rain

ag

e L

oss (

Inch

es)

Monthly Distribution of Sub-surface Drainage2000 Growing Season-Red Top

0%

10%

20%

30%

40%

50%

60%

70%

80%

May

June

July

August

Septe

mbe

r

Octob

er

Novem

ber

Decem

ber

Janua

ry

Febru

ary

Mar

chApr

il

Month

Per

cen

t o

f A

nn

ual

Dis

char

ge

Evans (West Field) Dittrich (East Field)2000 2001

Typically, April-May-Early June

account for approximately 75%

of the annual drainage

Nitrogen Fertilizer Application Rates to Corn

168

128

111 114

208

138

115 114

00

50

100

150

200

1995 1997 1999 2001 2002

Corn Growing Year

To

tal N

itro

gen

Rat

e [l

b/N

/acr

e]

West Field East Field

1997 and 1999 N Rate Design

St. Peter Nitrogen Fertilizer Rate Validation Project

2000 and 2001

120

130

140

150

160

0 60 90 120 150

20002001

N Fertilizer Rate (Lb/A) on Corn Following Soybeans

Bu

/ Acr

e

New UM Pub

Midwestern Water Quality Project Symposium

March 11, 2003

Country Inn and Suites

Mankato 9:00-3:00

Improve water quality in the Minnesota River Basin

Midwestern Water Quality Project Minnesota 2000-2002

CAP’s Partners•MN Corn Growers•St. Peter Wellhead Partnership•University of Minnesota•NAICC

Nitrate-N Changes After Implementation of UM BMPs: 1995-

2001N

itra

te-N

Con

cen

trati

on

s (

mg

/L)

05

1015202530

Nitrate-N Changes After Implementation of UM BMPs: 1995-

2001N

itra

te-N

Con

cen

trati

on

s (

mg

/L)

05

1015

2025

30

05

10152025303540

Jun-94 Oct-95 Mar-97 Jul-98 Dec-99 Apr-01 Sep-02Corn-95 Beans-96 Corn-97 Beans-98 Corn-99 Beans-00 Corn-01

Nitrate-N Concentration ConclusionsN

O3-N

m

g/L

iter

Approaching “background

levels” (Corn-Sb rotation with no

nitrogen fertilizer)

Nitrogen Fertilizer Application Rates to Corn

168

128

111 114

208

138

115 114

00

50

100

150

200

1995 1997 1999 2001 2002

Corn Growing Year

To

tal N

itro

gen

Rat

e [l

b/N

/acr

e]

West Field East Field

Nitrate-N Changes –Aggressive N Inputs/Management Changes

Nit

rate

-N C

on

cen

trati

on

s (

mg

/L)

05

1015202530

Red Top Growing Year Average NO3-N Concentration

0

5

10

15

20

25

1995 1996 1997 1998* 1999* 2000* 2001* 2002*Growing Year

*Note: 1998 through 2001 are flow weighted mean concentrations 2002 is a partial year.

NO

3-N

Co

nc

. [

mg

/L]

West Field (total) East Field

Soybeans

CornSoybeans

SoybeansCorn

Corn

Corn

Corn

Nitrate Concentrations by Growing Seasons and Crop

Nitrate-N Concentrations-Entire Monitoring Cycle at Red Top Farms

Nit

rate

-N C

on

cen

trati

on

s (

mg

/L)

0

5

10

15

20

25

30

35

Nitrate-N Losses from Corn and Soybeans 1997-2002

22 21 23

30

9

26

17

43

10

14

0

5

10

15

20

25

30

35

40

45

1997 1998 1999 2000 2001 2002Growing Year

Pounds

of N

itra

te-N

per

Acr

e

West Field East Field

Corn Soybeans CornCornCorn SoybeansSoybeans

Average N Losses: 22 lb/A/year

Total Phosphorus ConcentrationsFlow-Weighted by Growing Seasons

Total Phosphorus Flow Weighted Mean Concentration

0.00

0.05

0.10

0.15

0.20

0.25

GY 1998 GY 1999 GY 2000 GY 2001 GY 2002

Growing Year

Conce

ntr

ati

on (

mg/l

)

Evans (West) Dittrich (East)

Phosphorus (Total) Losses viaSub-Surface DrainageRed Top Growing Year Total Phosphorus Loss

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

1998 1999 2000 2001 2002Growing Year

Tota

l P L

oss

Expre

ssed in

Pounds

per

Acr

e

Evans (West)

Dittrich (East)

Red Top Benefits: Model Calibration

Sands et al, 2003

Sands et al, 2003

Pesticides at a Glance at the Red Top Site

APPLIED to FIELD Metolachlor (Dual) Acetochlor (Surpass) Nicosulfuron (Accent) Imazethapyr (Pursuit) Dicamba (Banvel) Atrazine Glyphosate (Roundup) Trifluralin (Treflan)

DETECTED in TILE WATER Metolachlor (Dual) Acetochlor (Surpass) Nicosulfuron (Accent) Imazathypyr (Pursuit) Dicamba (Banvel) Atrazine

Seven Mile Creek Watershed Characteristics

85% of the watershed is cropland-mostly prime;

Very high % tile drained;

Documented water quality challenges

Seven Mile Creek High Nitrogen Loading Minor Watershed

49.33

39.41

13.65

1.23 2.19 1.43 0.720.291.22

13.69

7.29

1.05

7.20

27.68

0

10

20

30

40

50

60

Dutch SevenMile

Bevens Chaska Carver Riley Credit Willow NineMile

Nit

rate

-N Y

ield

(lb

s/ac

re)

2000

2001

Seven Mile Creek Significant Phosphorus Loading Minor Watershed

1.65 1.64

1.25

1.11

0.28 0.29

0.34

0.040.07

0.200.14

1.15

0.74

0.34

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

Dutch SevenMile

Bevens Chaska Carver Riley Credit Willow NineMile

TP

Yie

ld (

lb/a

cre)

2000

2001

Red Top and Seven Mile Creek Nitrate-N “Runoff”: 2000-2001

3.9

9.7

3.8

13.4

3.5

16.6

0

2

4

6

8

10

12

14

16

18

2000 2001Year

Inch

es o

f R

un

off

West Field

East Field

Seven Mile Creek Site 3

Red Top and Seven Mile Creek Nitrate-N Concentrations: 2000-2001

13.5

12.2

14.5

12.2

16.8

10.5

0

2

4

6

8

10

12

14

16

18

2000 2001Year

Co

nce

ntr

atio

n (

mg

/l)

West Field East Field Seven Mile Creek Site 3

Field (Red Top) vs Watershed Scale (Seven Mile Creek) Nitrate-N Losses

0

5

10

15

20

25

30

35

40

45

2000 2001Year

Nit

rate

-N L

each

ing

Lo

sses

(lb

s/ac

re)

West Field

East Field

Seven Mile Creek Site 3

Field (Red Top) vs Watershed Scale (Seven Mile Creek) Nitrate-N Losses

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

2000 2001

Lbs/

Acr

e/In

ch o

f Run

off

Red Top (Both Fields)

Seven Mile

Due to the flashy drainage characteristics of these systems, continuous automated monitoring is absolutely critical!

The majority of the drainage and chemical movement occurs in very narrow timeframes.

Red Top Farm Demonstration Drainage and Response Times

Implementation of existing Nitrogen BMPs and University of Minnesota Fertilizer Recommendations resulted in a significant reduction in fertilizer inputs (25-30%), maintained yields and appears to have decreased N losses at this site by 40-50%.

Field scale Nitrogen strip validation work both at Red Top and within the St. Peter Source Water Protection Area continued to demonstrate that the UM Fertilizer Recommendations will optimize yields.

Red Top Farm Demonstration Nitrogen Management Conclusions

General Observations based on the First 5 Years at Red Top

Expect to see annual N LOSSES between 15-25 Lb/A under well managed corn-soybean production;

Unlikely that the 10 mg/L drinking water standard can be attained under corn-soybean rotations.

Red Top Farm DemonstrationNitrogen Losses in a Nutshell

Assuming that nitrate-N levels of 13-15 mg/Lunder a corn-soybean rotation are “backgroundlevels”, this means the following:

1) For every inch of drainage water, there is3.2 pounds of N loss; (simply calculated bydividing the concentration by the magic number Of 4.4. In this case 14 mg/L divided by 4.4=3.2)

2) Furthermore, since the average annual drainage is 7”, this means that 22 lb/A is losteach year.

Red Top Farm Demonstration Nitrogen Management Conclusions

The biggest water quality improvements will be realized through the implementation of basic nitrogen management such as correct rate selection and timing of application.

Monitoring tile drainage systems is a practical methodology for verifying effectiveness of Best Management Practices on a field-scale.

This system is an excellent educational tool for developing the linkage between ag practices and water quality issues.

Red Top Farm Demonstration General Conclusions

For more information from MDA Staff……..

Bill VanRyswyk-Surface Water Hydrologist, Mankato 507-389-5772

Brian Williams-Advisor, Le Sueur 507-665-6806

Paul Wotzka-Surface Water Hydrologist, Elba (Whitewater State Park) 507-932-5424

Bruce Montgomery-Unit Supervisor, St. Paul 651-297-7178