World Fertilizer N Consumption and

Challenges

C.S. Snyder, PhD, CCA

Nitrogen Program Director

Nitrogen Use Efficiency ConferenceStillwater, Oklahoma

August 3, 2010

Background• N is essential to the survival of all life

• Over 40% of the people on Earth owe their existence to the food production made possible by N fertilizers

• “Human alterations of the N cycle have caused a variety of environmental and human health problems ranging from too little to too much reactive N in the environment.” (Woods Hole Research Center)

• half the synthetic N fertilizer ever used has been utilized since 1985 (Howarth, 2005).

http://www.whrc.org/policy/global_nitrogen.htm

A Growing World Population Requires an Increased Global Food

Supply

”Stewart et al. (2005) reviewed data representing 362 seasons of crop production and reported at least 30 to 50% of crop yield can be attributed to commercial fertilizer inputs.”

“…food production will have to increase by 50% by 2013 and double in 30 years to help solve the current food crisis.” (Roberts. 2009. Better Crops 93(2):12-15)

World Fertilizer N Consumption, 1961-2007

IFA Statistics 2010

World Fertilizer N Consumption by Source

IFA Statistics 2010

U.S. N Source Consumption: 1970-2007

Source: H. Vroomen -TFI, and AAPFCO

World and U.S. Fertilizer N Consumption

Source: IFA Statistics, 2010

World

U.S.

U.S. Fertilizer N Consumption

Source: AAPFCO and TFI, 2010

0.5% increase per year, since 1980

Acres of corn grain harvested (million)

Corn grain yield, bu/A

Corn grain production, bu (billion)

1981 74.524 108.9 8.119

2008 78.510 153.9 12.092

change 5% 41% 49%

change/yr 0.002% 1.5% 1.8%

Source: Heffer. 2009. Assessment of Fertilizer Use by Crop at the Global Level: 2006/07 – 2007/08 . IFA. Paris, France

Increased N Inputs and Global N FlowsPose Environmental Challenges

Fertilizer, 31 Tg N

Meat, 0.8 Tg N

Grain, 12 Tg N

Galloway et al. 2008. Science 320, 889

1 Tg = 1 million tonnes (Mt)

Global N Use Efficiency

• Can be defined many different ways– Ladha et al. 2005. Advances in Agronomy 87: 85-176.– Dobermann. 2007.IFA Workshop on Fertilizer BMPs.

Brussels, Belgium. March 7-9, 2007.

• Worldwide fertilizer N use efficiency in cereal production was estimated at 33% (Raun and Johnson. 1999. Agron. J. 91:357–363)– NUE =

(est. grain N removal – (est. N from soil + rainfall))

est. cereal fertilizer N consumption x 100

Global Nitrogen Use Efficiency, Expressed as Apparent N Recovery (REN)• <50% N use efficiency globally by most crops

(Balasubramanian et al., 2004; Ladha et al., 2005)

• typical on-farm REN (Dobermann and Cassman, 2002)

– only 30% in rice and 37% in maize,

– with good management REN could be 50 to 80%

• in cereal crop research – total REN from a one-time application of N averages 50 to 60%, and

40 to 50% under most on-farm conditions (Dobermann, 2007)

CF Industries

OSU

Kitchen and Goulding (2001) in Nitrogen in the Environment:

Sources, Problems and Management

• “ nitrogen use efficiency …rarely exceeds 70% ……. often ranges from 30-60%”

• “conversion of N inputs to products for arable crops can be 60-70% or even more”

EPA SAB Integrated N Committee report on reactive N (Aug. 27, 2009 DRAFT): recommends crop N-uptake efficiencies increase by up to 25% over current practices, through a combination of knowledge-based practices and advances in fertilizer technology

How Much N Loss via Major Pathways ?

• Runoff, leaching and drainage

• Ammonia volatilization

• Denitrification and N2O emissions (direct and indirect)

y = 1.8242x - 3517.2R² = 0.4484

y = 0.3668x - 591.26R2 = 0.0464

y = -0.2369x + 495.89R² = 0.8657

20

25

30

35

40

40

60

80

100

120

140

160

180

1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007

Groundw

ater Nitrate

-N (m

g/L)

N (l

bs/a

cre)

Groundwater N

N Removed in Grain

N Fertilizer Applied

α = 0.01

NORTH

α = 0.001

N price doubles

Irrigation Water: NO3-N = -0.1142x + 245.55R² = 0.68

Soil Residual NO3-N = -1.7725x + 3627.7R² = 0.42

0

20

40

60

80

100

120

140

160

180

200

10

12

14

16

18

20

1985 1990 1995 2000 2005 2010

Soil R

esid

ual N

O3-

N (k

g ha

-1)

Irrig

ation

Wat

er N

O3-

N (m

g L-1

)

Education & Natural Resources District Regulation Help Lower Groundwater NO3

Central Platte Valley, Nebraska

Source: Personal communication with Richard Ferguson (2010)

For more info refer to Exner et al.2010. The Scientific World Journal 10:286-297.

River N Flux is Predicted to Increase with Increased N Inputs (Bouwman et al., 2005)

Global N Input River N Flux

0

100

200

300

400

500

600

1970 1995 2030

N in

pu

t, T

g p

er

year transition country

industrialized country

developing country

0

10

20

30

40

50

60

1970 1995 2030

Riv

er

N f

lux,

Tg

per

yr transition

country

industrialized country

developing country

1 Tg = 1 million tons (Mt)

USGS Estimates of Loss and Delivery of

N and P to the Gulf of Mexico

SPARROW - Modeled Estimate of N and P Discharge in Watersheds of the Mississippi R. Basin

kg/ha.01 .01- 0.10.1 to 11 to 55 to 10>10

kg/ha.001 .001- 0.010.01 to 0.10.1 to 0.50.5-1.0>1

Alexander et al. Environ. Sci. Technol. 2008, 42, 822–830

Gulf of Mexico Hypoxia Areanew Aug. 2, 2010

Square miles of hypoxia

Year

No

Dat

a

15

Hypoxia data from N. Rabalais, LUMCON

2015 HypoxiaGoal

Hypoxic Zones Are Increasing Globally

Diaz and Rosenberg. 2008.Science 321:926-929

NH3 Volatilization Losses from N Fertilizers• Up to 45% of the urea-N applied under surface-applied,

warm, moist field conditions can be lost as NH3(Watson, 2005)

• Volatilization of NH3 from N fertilizers has been estimated by Bouwman et al. (2002) at:

– 18% in developing countries, based on N sources used and environmental conditions,

– 7% in industrialized countries

– Estimated global median NH3 loss

• 14% for fertilizer N

• 23% for manure N

• NH3 volatilization loss has exceeded

– 50% of applied urea N in transplanted rice paddy systems in Asia

– 30% of the applied N if flooding is delayed for up to 14 days after urea is surface broadcast in drill-seeded flood-irrigated rice

2008 Total U.S. GHG Emissions, based on CO2 equivalents

Agriculture share6% of all U.S. GHG emissions

U.S. EPA Inventory of GHG Emissions and Sinks,1990 – 2008 (2010)

2007 Total EU-27 GHG Emissions, based on CO2 equivalents

Agriculture share9% of all EU-27 GHG emissions

European Environment Agency. 2010. Greenhouse gas emission trends and projections in Europe 2009

Radiative Forcing (GWP)N2O x 296 = CO2e CH4 x 23 = CO2e

U.S. GHG Emissions & N2O from Ag Soil Management

(EPA 2010 U.S. GHG inventory, 1990-2008)

3.9%3.7%

3.3% 3.5% 3.5% 3.6%3.4%

Agricultural soil management N2O as portion of total U.S. GHG emissions

Agricultural soil management includes fertilizer application and cropping practices; the largest sources of N2O emissions,

accounting for 68% of all U.S. N2O emissions in 2008

1 gigaton (Gt) = 109 tonnes = 1012 kg = 1015 g = 1,000 Tg = 1018 g1 terragram (Tg) = 1012 g = 109 kg =106 tonnes

Ag soil mgmt.4% in EU-27

in 2007

Source: Flynn and Smith. 2010. Greenhouse gas budgets of crop production – current and likely future trends. IFA. Paris, France

Nitrous Oxide (N2O) Emissions from Agricultural Soils, 1990-2020 (EPA, 2006)

4R Nutrient Stewardship

Crops & Soils 42(2): Mar-Apr 2009

Crops & Soils 42(3): May-Jun 2009

Crops & Soils 42(4): Jul-Aug 2009

Crops & Soils 42(5): Sep-Oct 2009

Crops & Soils 42(6): Nov-Dec 2009

Know Your Fertilizer Rights: Right Place by T.S. Murrell (IPNI), G.P. Lafond (AAFC), and T.J. Vyn (Purdue U.)

http://www.ipni.net/4r

Agriculture, Ecosystems and Environment (2009) 133:247-266.

Fertilizer N : source, rate, timing, and place of application

N Rates Used by Farmers on Corn ?USDA NASS/ERS and Corn N Rate Calculator

• USDA: average N rate applied for corn in 2000-2005 was 135 lb/A (151 kg/ha)

• N Rate Calculator: @ $0.36/lb of N and $3.60/bu of corn: 2005 applied,

MRTN, lb N/A lb N/A (NASS)– Illinois 168 146

– Indiana 171 147

– Iowa 125 141

– Michigan 130 128

– Minnesota 105 139

– Ohio 174 161

• 6-state ave. = 146 144

Fertilizer N Effects on Profile SOC After 39 Years of Continuous Corn with a

Winter Cereal Cover Crop

Grove et al. 2010. Better Crops 93(4):6-8

Source: Halvorson et al., 2009 Better Crops 93(1):16-18; Submitted to JEQ on Feb. 1, 2010.

Corn grain yield (Mg/ha) is shown near the bottom of each bar

Duration III and ESN = Polymer Coated urea

SuperU and UAN+AP contain urease and nitrification inhibitors

20 to 50 % reduction possible with N source selection

1 Mg/ha =15.9 bu/A

192 bu/A

N Source Affects Growing Season N2O and CO2 Emissions, and Corn Yields (MN)

N2O emissions with urea were half of those with anhydrous ammonia

Venterea et al. 2010. Soil Sci. Soc. Am. J. 74:407–418

•N rate = 146 kg N/ha,in spring 1-2 weeks before planting:•NH3 knifed, urea bdcst. & incorporated

“It is likely that the effects of fertilizer form will be site specific and depend to some extent on soil pH.”

N2O Emissions Tend to Increase as N Rates Increase

(Halvorson et al., 2009. Better Crops 93:16-18)

N Rate Effects on Daily N2O Flux in Corn (8-site-years, MI)

Millar et al. 2010. Mitig. Adapt. Strateg. Glob. Change. 15:185–204.

Snyder et al. 2009. Agric. Ecosyst. Environ. 133:247-266

Is Lower Input, Less Intensive Ag the Answer?

State Rotation & System

Tillage Food Yield, Gcal/ha/yr

N2O GWP/Food Yield

Net GWP/Food Yield

MI C-S-W CT 12 43 95

MI C-S-W NT 13 43 11

MI C-S-W low input w/legume

CT 12 50 53

MI C-S-W organic w/legume

CT 9 62 46

NE C-C BMP CT 48 24 41

NE C-C intensive CT 51 41 60

NE C-S BMP CT 35 26 107

NE C-S intensive CT 37 34 101

More Intensive Systems Can Help Lower GWP per Unit of Food Produced

- Ecological Intensification -

Snyder et al. 2009. Agric. Ecosyst. Environ. 133:247-266

State Rotation & System

Tillage Food Yield, Gcal/ha/yr

N2O GWP/Food

Yield

Net GWP/Food

Yield

MI C-S-W CT 12 43 95

MI C-S-W NT 13 43 11

MI C-S-W low input w/legume

CT 12 50 53

MI C-S-W organic w/legume

CT 9 62 46

NE C-C BMP CT 48 24 41

NE C-C intensive CT 51 41 60

NE C-S BMP CT 35 26 107

NE C-S intensive CT 37 34 101

More Intensive Systems Can Help Lower GWP per Unit of Food Produced

Snyder et al. 2009. Agric. Ecosyst. Environ. 133:247-266

4X more food

The Key is to Limit Potential “Surplus N”

Van Groenigen et al. 2010. Europ. J. Soil Sci. doi: 10.1111/j.1365-2389.2009.01217.x

“ … agriculturalmanagement practices to reduce N2O emissions should focus on optimizing fertilizer-N use efficiency undermedian rates of N input, rather than on minimizing N application rates.”

Will Variable-Rate N Using Canopy Sensors Deliver Environmental Benefits?

Source: Roberts, Kitchen, Scharf & Sudduth. 2010. Agron. J. 102: 85-95

Stanford University Source: Burney et al. 2010. Proc. Natl. Acad. Sci. 107(26):12052-12057

Each dollar invested in higher crop yields has resulted in 68 fewer kg of C (249 kg CO2e) emitted.

A Preliminary

Nutrient Use Geographic Information System (NuGIS)for the U.S.

2010

Estimated N balance by watershed, 1987.

IPNI, 2010

Estimated N balance by watershed, 1992.

IPNI, 2010

Estimated N balance by watershed, 1997.

IPNI, 2010

Estimated N balance by watershed, 2002.

IPNI, 2010

Estimated N balance by watershed, 2007.

IPNI, 2010

U.S. Partial N Balance

1987 31.2 lb/A

1992 33.6

1997 32.4

2002 32.8

2007 35.3

Improving N Use Efficiency

• Implementation of fertilizer best management practices (BMPs)

• Site-Specific Nutrient Management (SSNM) - to help achieve improved economic results and environmental objectives

www.ipni.net

Better Crops, Better Environment … through Science

Thank You