Water resources and biofuels water quality april 2012

Water Resources: Issues & Opportunities Water Quality

Hypoxia – What is it?

An area of low dissolved oxygen concentrations that cannot support marine life. Typically O2 < 2 ppm

Hypoxia – Why does it occur?

Algae bloom in freshwater Algae settle to bottom Algae decomposition consumes O2

Hypoxia – How large an area?

http://www.epa.gov/gmpo/pdf/2007-hypoxia-pred-web-5.pdf

Turner and Rabalais, 2007

x

X – size in 2008

Hypoxia – Is nutrient flux constant?

co.water.usgs.gov

Hypoxia – Nitrogen Source?

www.umces.edu/President/hypoxia.htm

20 – 25 lb/A

Hypoxia – Source of Phosphorus?

Look to the Future

40

50

60

70

80

90

100

1980 1985 1990 1995 2000 2005 2010 2015

Planted area: Corn, wheat, and soybeans

Million acres

Corn

Wheat

Soybeans

Source: USDA Agricultural Projections to 2016, February 2007.Economic Research Service, USDA.

USDA Agricultural Projections to 2016D. R. Keeney

Corn/Soybean and Perennial Nitrate-N Concentrations in Tile

Drain Tile drainage system U of MN - Lamberton

0

5

10

15

20

25

Corn/Bean Perennials

mg/LMidpointof range

Gyles Randall, 2003

D. R. Keeney

Tom Kaspar

Tom Kaspar

Rye after corn silage

Kaspar et al., JEQ 36:1503-1511

Cumulative annual nitrate-N load of drainage water for 2002-2005

40.4

81.1

47.250.8

11.2 11.1

19.8

34.433.9

23.0

0

10

20

30

40

50

60

70

80

90

2002 2003 2004 2005 Avg.

Ann

ual n

itrat

e-N

load

(kg/

ha)

ControlRye Cover Crop

Cropping System Impacts on Drainage Water Quality and Quantity

Dr. Matt Helmers, Dr. Xiaobo Zhou, and Carl Pederson

ISU South Reynoldson FarmBoone County, IAComparison of Biofuel Systems (COBS)Each of the 24 plots is 90 ft x 200 ft

Photo by T. SchultzAugust 2009

Tile Drainage Flow 2010

Tile Drainage Flow 2011

NO3-N Concentration 2010

NO3-N Concentration 2011

NO3-N Loss 2010

NO3-N Loss 2011

Iowa Daily Erosion Project

Estimates daily soil erosion, runoff and soil moisture for the state of Iowa Daily estimations since 2002 Published in Jan/Feb 2006 Journal of the

Soil and Water Conservation Society Served on the web at

http://wepp.mesonet.agron.iastate.edu Parameterizes WEPP erosion model with

radar rainfall, climate stations, and NRI

Simulated crops Eight scenarios based on ISU research

Rotation Tillage Residue Removal

Cover Crop Abbreviation

NRI NRI No No NRI

Corn/Soy Min-till No No CS-MT

Cont. Corn Min-till Yes No CC-MTRR

Corn/Soy No-till No No CS-NT

Cont. Corn No-till No No CC-NT

Cont. Corn No-till Yes No CC-NTRR

Cont. Corn No-till Yes Yes CC-NTRRCC

Switchgrass No-till Yes No Sw-NTRR

NEXRAD – Aug 22, 2007

Statewide mean precipitation: 1.56 in.

Switchgrass – NT, RR

Sw-NTRRCC-NTCS-NTCC-NTRRCC-NTRRCCNRICS-MTCC-MTRR

Cont. Corn – NT

Sw-NTRRCC-NTCS-NTCC-NTRRCC-NTRRCCNRICS-MTCC-MTRR

Corn/Soybean – NT

Sw-NTRRCC-NTCS-NTCC-NTRRCC-NTRRCCNRICS-MTCC-MTRR

Cont. Corn – NT, RR

Sw-NTRRCC-NTCS-NTCC-NTRRCC-NTRRCCNRICS-MTCC-MTRR

Cont. Corn – NT, RR, CC

Sw-NTRRCC-NTCS-NTCC-NTRRCC-NTRRCCNRICS-MTCC-MTRR

NRI Projected Rotation

Sw-NTRRCC-NTCS-NTCC-NTRRCC-NTRRCCNRICS-MTCC-MTRR

Corn/Soy - MT

Sw-NTRRCC-NTCS-NTCC-NTRRCC-NTRRCCNRICS-MTCC-MTRR

Cont. Corn - MTRR

Sw-NTRRCC-NTCS-NTCC-NTRRCC-NTRRCCNRICS-MTCC-MTRR

Event Summary

Management 8/22/2007 Mean Loss (tons/acre)

8/22/2007 Mean Runoff (in)

Sw-NTRR 0.044 0.657

CC-NT 0.113 0.662

CS-NT 0.184 0.651

CC-NTRR 0.230 0.649

CC-NTRRCC 0.232 0.650

NRI 0.320 0.640

CS-MT 0.406 0.647

CC-MTRR 0.458 0.646

Cum

ulat

ive

surfa

ce ru

noff

(in a

cre-1

)

0

1

2

3

4

5

6

100% Row-crop10% Perennial Cover at Toe Slope10% Perennial Cover in Contour Strips20% Perennial Cover in Contour Strips

Date

Cum

ulat

ive

sedi

men

t exp

ort (

lb a

cre-1

)

0

5000

10000

15000

20000

100% Row-crop10% Perennial Cover at Toe Slope10% Perennial Cover in Contour Strips20% Perennial Cover in Contour Strips

Thoughts to Ponder

Corn grain ethanol N applications likely unchanged P applications likely unchanged Water quality impacts likely unchanged Cover crop management good for system

Thoughts to Ponder (II) Cellulosic - conversion of corn stalks

Likely greater water quality challenges than current ag systems

Opportunities with cover crops to improve WQ Sediment/Phosphorus issues increase

Cellulosic – conversion of perennials Favorable WQ opportunities

• Surface • Subsurface