Technical Challenges to

Meeting Goals at

Multiple Scales

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 1.12

Sandusky 0.311 1.41

Honey Cr. 0.369 1.29

Rock Cr. 0.250 1.38

Lake Erie and Harmful Algal Blooms

2011 Central Lake Erie Basin Microcystis-containing bloom

Measured DRP

(kg P/ha)

TP

(kg P/ha)

Maumee 0.273 1.12

Sandusky 0.311 1.41

Honey Cr. 0.369 1.29

Rock Cr. 0.250 1.38

Binational Agreement to:

Reduce annual TP by 40%

Reduce Spring SP and TP by 40%

Targets DRP

(kg P/ha)

TP

(kg P/ha)

Maumee 0.16 0.67

Sandusky 0.19 0.85

Honey Cr. 0.22 0.77

Rock Cr. 0.15 0.83

WHAT CAN WE DO?

Buffers

Nutrient Interception

Wetlands (IA-CREP)

Stream

Diversions

Near-Zero

Discharge Drainage

Bioreactors

Restored Prairie Pothole

Wetlands

Controlled

Drainage

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 P

HY09 Soluble P

HY10 Soluble P

HY11 Soluble P

84.6%

61.9%

44.3%

81.1%

Fertilizer Spreading

“Season”

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

Vo

lum

etr

ic D

ep

th (

mm

)

0

20

40

60

80

100

120

140

160

180Precip > PET

PET

2005-2010 Precip

Drainage and Fertilizer Spreading Season

Nutrient Budgets, Sources and Pathways

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

Wheat

18.5 lb P/acFertilizer

17.6 lb P/ac Harvest

NoFertilizer

Field 2 – 6.7 ac

Soybean

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 River

4,064,000 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

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

10 20 30 40 50 60 70 80 90 100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

Mor

e

FREQ

UEN

CY A

MO

NG

120

SAM

PLES

Phosphorus Concentration in 0-6" Surface Soil (mg P/ kg soil - or - ppm)

Phosphorus Content after Harvest data from Diane Stott

According to the Tri-state Fertility Guide, no

P fertilizer application recommended

beyond 50 ppm P

St. Joseph River Watershed

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Ma

tso

n D

itch

Swartz Ditch

W S

mith

Ditc

h

Cedar C

reek

Dib

bling D

itch

Lein

s Ditch

Ho

ffeld

er

Dit

ch

Ced

ar Cree

k

Mats

on Ditc

h

AD

AS2AS1

F34

CME

CLG

BME

BLG

AME

ALG

MI

IN

OH

MI

IN

OH

MI

Ontario

Tile Drainage

Direct Drainage

Pot-Hole

!

LowPoint

¯

0 50 100 150 200 250

Miles

0 5 10 15 20 25

Miles

0 0.5 1 1.5 2 2.5

Miles

Nutrient losses were higher from watersheds with more:

‒ Direct Drainage

‒ Pothole Drainage

Influence of Drainage Class on Nutrient Losses

Soil Test Phosphorus 0-2" (mg/kg)

0 100 200 300 400 500 600

DR

P c

on

cen

trati

on

(m

g/L

)

0.0

0.5

1.0

1.5

2.0

DRP concentration range

site 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 inch

Surface Q = 0.03 inch

Tile Q = 0.16 inch

Precip = 1.56 inch

Surface Q = 1.27 inch

Tile Q = 0.22 inch

Field 1 Field 2 Field 3 Field 4

Rel

ativ

e S

ub

surf

ace

Tile

Dis

char

ge

(%)

0

20

40

60

80

100

120

Annual Relative Volume of Discharge

Through Subsurface Tile – St. Joe

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 (Culley

and Bolton, 1983)

Soluble P Total P

2005 0.317 0.234

2006 0.346 0.300

2007 0.313 0.264

2008 0.756 0.759

2009 0.591 0.485

2010 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

T

ile L

osse

s (

kg

)

0

20

40

60

80

100

120

140

160

Total P

Soluble P

y = 0.457x+0.219

R2 = 0.86

y=0.342x+0.173

R2=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

P Applications – Single Season

P Recommended (kg P ha-1

)

0 10 20 30 40 50 60

P A

pplie

d (k

g P

ha-1

)

0

20

40

60

80

100

Diammonium Phosphate

Poultry Litter

Monoammonium Phosphate

No Fertilizer

Polyphosphate (Planter)

Polyphosphate (Sprayer)

1:1 Line

P Application - Rotation

P Recommended (kg P ha-1

)

0 20 40 60 80 100

P a

pplie

d (k

g P

ha-1

)

0

20

40

60

80

100

120

140

160

180

200

Diammonium Phosphate

Poultry Litter

Monoammonium Phosphate

No Fertilizer

Polyphosphate (Planter)

Polyphosphate (Sprayer)

1:1 Line

Conservation Practices

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

Conservation Practices Generally Designed for Erosion

Stop the sediment, stop the P

Expectations for Water Quality Improvement

Grassed waterwaysContour filter strips

Conservation cover

Practices for Managing Runoff & Water Quality

Sediment detention basins

Relative Change in Annual Load for

Nutrients and Sediments by Conservation Practice

NH4-N NO3-N TKN Soluble P Total P Sediment

Rel

ativ

e C

hang

e in

Ann

ual L

oad

-100

-50

0

50

100

150

200

Grassed Waterway

Blind Inlet

Conservation Crop Rotation

Tillage

Monitored Conservation Practices in WLEB

APEX Modeling of All Conservation in St. Joe

Nitrogen Loading from Fields Where Single or Multiple

Conservation Practices Have Been Implemented

If No Practices With Conservation

Nitr

ogen

(lb)

0

2000000

4000000

6000000

8000000

10000000

Sediment Loading from Fields Where Single or Multiple

Conservation Practices Have Been Implemented

If No Practices With Conservation

Sed

imen

t Loa

d (to

ns)

0

10000

20000

30000

40000

50000

60000

1 Conservation Practice

2 Conservation Practices

3 or more Conservation Practices

Certainty Programs – Stewardship Tool for

Environmental Performance

Agricultural Conservation Planning Framework

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

WHAT CAN WE DO?

Buffers

Nutrient Interception

Wetlands (IA-CREP)

Stream

Diversions

Near-Zero

Discharge Drainage

Bioreactors

Restored Prairie Pothole

Wetlands

Controlled

Drainage

No single source of P

No single pathway of P

No silver bullet

Most farmers do what is asked

If we are giving the wrong advice, it is the farmer that pays the price

Conclusions

?Thank You!