Identifying Nutrient Sources, Flowpaths, and Priority Practices

Douglas R. Smith, USDA-ARS

Lake Erie and Harmful Algal Blooms

2011 Central Lake Erie Basin Microcystis-containing bloom

DRP (kg P/ha)

TP (kg P/ha)

Maumee 0.273 1.12Sandusky 0.311 1.41Honey Cr. 0.369 1.29Rock Cr. 0.250 1.38

Nutrient Budgets, Sources and Pathways

2010 Field and Watershed Mass Balance

Field 4 – 8.6 ac

Soybean

16.7 lb P/acFertilizer

32.6 lb P/ac Harvest

Field 1 – 5.4 ac

Corn

20.8 lb P/ac Harvest

Field 3 – 9.9 ac

Soybean16.7 lb P/acFertilizer

32.6 lb P/ac Harvest

78.4 lb P/ac Poultry Litter

Field 2 – 6.7 acCorn

78.4 lb P/ac Poultry Litter

20.8 lb P/ac Harvest

Ditch Site 1736 ac

Ditch Site 24,780 ac

Ditch Site 310,600 ac

Stream Site 447,600 ac 0.52 lb P/ac

Lake Erie

Maumee River4,064,000 ac

30.2 in. rain

1 lb P205 = 0.44 lb P

100 lb DAP/ac = 46 lb P205/ac = 20.1 lb P/ac

2011 Field and Watershed Mass Balance

Field 4 – 8.6 ac

Wheat

18.5 lb P/acFertilizer

17.6 lb P/ac Harvest

Field 1 – 5.4 ac

Soybean

16.8 lb P/ac Harvest

Field 3 – 9.9 ac

Wheat18.5 lb P/acFertilizer

17.6 lb P/ac Harvest

NoFertilizer

Field 2 – 6.7 acSoybean

NoFertilizer

17.1 lb P/ac Harvest

Ditch Site 1736 ac

Ditch Site 24,780 ac

Ditch Site 310,600 ac

Stream Site 447,600 ac 0.68 lb P/ac

Lake Erie

Maumee River4,064,000 ac

36.5 in. rain

1 lb P205 = 0.44 lb P

100 lb DAP/ac = 46 lb P205/ac = 20.1 lb P/ac

Legacy Phosphorus in Fields Crop roots utilize only a small proportion of the soil volume leading to poor nutrient capture

A large proportion of applied P is immobilized in soils by inorganic and organic processes

Critical soil test P levels vary widely from site to site leading to insurance‐based applications

Soil sampling/analysis is crude, has high uncertainties leading to potential misinterpretation

Contributions from organic P and subsoil P are largely ignored

Courtesy: Paul Withers

According to the Tri-state Fertility Guide, no P fertilizer application recommended beyond 50 ppm P

J F M A M J J A S O N D

Volu

met

ric D

epth

(mm

)

0

2 0

4 0

6 0

8 0

1 0 0

1 2 0

1 4 0

1 6 0

1 8 0P re c ip > P E TP E T2 0 0 5 -2 0 1 0 P re c ip

• 25% of cropland in US and Canada could not be farmed without tile drainage (Skaggs et al., 1994):• soils with the greatest inherent production potential

• Tile Drainage (Fausey et al., 1987):• provides trafficable conditions for field operations• promotes root development by preventing exposure of plants to excess water

Drainage and Fertilizer Spreading Season

Hydrologic Year 2008-2011 Maumee River Soluble Phosphorus Loading

Day of Hydrologic Year (Day 1 = October 1)

0 100 200 300

Tota

l Pho

spho

rus

Load

(kg)

0

200000

400000

600000

800000

HY08 Soluble PHY09 Soluble PHY10 Soluble PHY11 Soluble P

84.6%

61.9%

44.3%

81.1%

Fertilizer Spreading “Season”

St. Joseph River Watershed

!\

!\

!\ !\

!\

!\

!\

!\

!\

!\

!\

!\ !\

!\!\!\!\!\!\

Matson D

itch

Swartz Ditch

W Smith D

itch

Cedar Creek

Dibbling Ditc

h

Leins Ditch

Hof

feld

er D

itch

Cedar Creek

Matson Ditch

AD

AS2AS1

F34

CME

CLG

BME

BLG

AME

ALG

MI

IN

OH

MI

INOH

MI

Ontario

Tile Drainage

Direct Drainage

Pot-Hole

! LowPoint

¯

0 50 100 150 200 250

Miles0 5 10 15 20 25

Miles

0 0.5 1 1.5 2 2.5Miles

Nutrient losses were higher from watersheds with more:‒ Direct Drainage‒ Pothole Drainage

Influence of Drainage Class on Nutrient Losses

2008.0 2009.0 2010.0 2011.0

Tota

l P in

Sur

face

Run

off (

kg P

/ha)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Field 1 Field 2 Field 3 Field 4 Maumee

Total P in Surface Runoff from Fields and Maumee River

2008 2009 2010 2011

Tota

l P in

Tile

(kg/

ha)

0.0

0.5

1.0

1.5

2.0

2.5

Field 1 Tile Field 2 Tile Field 3 Tile Field 4 Tile Maumee

Total P in Tile Flow from Fields and Maumee River

Soil Test Phosphorus 0-2" (mg/kg)0 100 200 300 400 500 600

DR

P co

ncen

trat

ion

(mg/

L)

0.0

0.5

1.0

1.5

2.0

DRP concentration rangesite median

Relationship between soil test phosphorus and dissolved phosphorus concentration in tile discharge (UBWC and Upper Wabash watersheds)

What’s Wrong with the Current System?

Courtesy: K. King

Surface and Tile Discharge – St. Joe

Precip = 0.73 inchSurface Q = 0.03 inchTile Q = 0.16 inch

Precip = 1.56 inchSurface Q = 1.27 inchTile Q = 0.22 inch

3/2 /12 6:00 3/2 /12 6:00 3/3 /12 6:00 3/3/12 6:00

flow

rate

(lps

)

0

10

20

30

40pr

ecip

itatio

n (m

m)

0

1

2

3

4

5

surface d ischargetile d ischargeprecip ita tion

0

2

4

6

8

10

12

14

16

prec

ipita

tion

(mm

)

0

2

4

6

8

10

12

14

surface runofftile dischargeprecipitation

5/8/12 5/9/12 5/10/12

Dis

char

ge (L

ps)

0

2

4

6

8

10

12

14

160

2

4

6

8

10

12

14

3 /2 /1 2 6 :0 0 3 /2 /1 2 6 :0 0 3 /3 /1 2 6 :0 0 3 /3 /1 2 6 :0 0

flow

rate

(lps

)

0

1 0

2 0

3 0

4 0

prec

ipita

tion

(mm

)

0

1

2

3

4

5

s u r fa c e d is c h a rg et ile d is c h a rg ep re c ip ita t io n

Two different tile: same soil, different responses

0.5 inch rainfall 1.25 inches rainfall

EOF Results – (OH – UW; K. King)

Watershed Results—2005‐2010 UBWC

Courtesy:  K. King

40% of annual total phosphorus load at EOF from tile discharge (Enright and Madramootoo, 2004)

25% of TP and 50% of soluble P leaving watershed originated in tile drainage (Culleyand Bolton, 1983)

Soluble P Total P2005 0.317 0.2342006 0.346 0.3002007 0.313 0.2642008 0.756 0.7592009 0.591 0.4852010 0.669 0.630

AVG 0.499 0.445

Fraction of annual watershed loading

originating from tile

Watershed Loss (kg)

0 20 40 60 80 100 120 140 160

Ti

le L

osse

s (k

g)

0

20

40

60

80

100

120

140

160

Total PSoluble P

y = 0.457x+0.219R2 = 0.86

y=0.342x+0.173R2=0.72

LEGACY PHOSPHORUS

Sediment source tracking indicated about

50% of sediment was from field sources and 50% from stream bank.

Roughly ½ of sediment (and by proxy P) is from stream bank or stream

bed

Conservation Practices

Ohio P Task Force International Joint Commission

Goals to reduce P loading to Lake Erie by ~40%

Expectations for Water Quality Improvement

Grassed waterwaysContour filter strips

Conservation cover

Practices for Managing Runoff & Water Quality

Sediment detention basins

Alternative Surface Drainage

Tile Riser Blind Inlet

Novel Practices: Re-Saturated Buffer

In-Channel Phosphorus Retention

Mark Tomer, ARSJoe Magner, Univ. Minn.

Entrained wetlands

Constructed wetlands

Two-stage ditch

Stream restoration/reconnection

Pete Kleinman, ARS

Decrease P loading to achieve WQ goalsNo single source of P No single pathway of PNo silver bulletWill require an “all of the above” approach to meet WQ goalsHow do we plan for landscape scale conservation???

Conclusions

?Thank You!

Total and Soluble Phosphorus Loading

Dave Baker and Pete Richards, Heidelberg University

“Peak” adoption of no‐till

P Loading to Lake Erie

Municipal Direct15%

Municipal Indirect5%

Industry PS Direct0%

Industry PS Indirect0%

Trib Monitored52%

Trib not Monitored18%

Atmospheric Deposition

6%

Lake Huron4%

P Loading to Lake Erie (1994-2008)

Average Total Phosphorus Loading to Lake Erie is 10,875 ton/year

Dolan and Chapra, 2012

SP Load by Management

No-Till Rotation Till Conv Till/8yr Rot

SP L

oad

(g h

a-1)

0

100

200

300

400

500

TP Load by Management

No-Till Rotation Till Conv Till/8yr Rot

TP L

oad

(g h

a-1)

0

200

400

600

800

1000

1200

1400

Informational Survey of Farmers and CCAs

Manage or advise > 35,000 ha

Asked about N, K and P deficiency

N and K deficiency common

P deficiency only when‒ Sidewall compaction‒Cool/wet post‐emerge‒Herbicide damage

Hydrologic Year 2008-2011 Maumee River Total Phosphorus Loading

Day of Hydrologic Year (Day 1 = October 1)

0 100 200 300

Tota

l Pho

spho

rus

Load

(kg)

0

1000000

2000000

3000000

4000000

HY08 Total PHY09 Total PHY10 Total PHY11 Total P

86.7%

49.5%

87.4%

45.8%

Fertilizer Spreading “Season”