Transcript Slide 1

Nitrogen Contributions to the
Greenhouse Gas Effect and
Global Warming
C.S. Snyder, PhD, CCA
Nitrogen Program Director
Acknowledgements
•
Dr. Tom Bruulsema
•
Dr. Tom Jensen
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)
http://www.whrc.org/policy/global_nitrogen.htm
Nutrient Management (Ch.9)
by Robert Howarth & others (2005)
• “Human activity has
greatly increased the flux
of nutrients through the
landscape, roughly
doubling the global flux of
nitrogen and tripling the
flux of phosphorus in the
landscape over natural
values.”
• “half the synthetic
nitrogen fertilizer
ever used on Earth
has been utilized
since 1985.”
•
N- ecological & environmental effects
•
eutrophication of coastal marine ecosystems,
freshwater lakes
acid rain effects on freshwater and terrestrial
ecosystems
Millenium Ecosystems Assessment
loss of biodiversity: aquatic and terrestrial
ozone creation @ ground-level (leads to loss of
agricultural and forest productivity)
ozone destruction in stratosphere (increased
UV-B radiation on Earth)
Contribution to global warming (GHGs).
Increased health effects include:
•
•
•
•
•
•
–
–
–
–
–
asthma and respiratory malfunction,
pollen production, and increased allergies and
asthma
bluebaby syndrome
risk of cancer and other chronic diseases from nitrate
in drinking water
risk of a variety of pulmonary and cardiac diseases
from production of fine particles in the atmosphere.
Greenhouse Gases (GHGs)
and their sources
• Carbon Dioxide (CO2): fossil fuels (oil, natural gas, and coal),
solid waste, trees and wood products, and also as a result of
other chemical reactions (e.g., manufacture of cement).
• Methane (CH4): production and transport of coal, natural gas,
and oil; livestock and other agricultural practices and by the
decay of organic waste in municipal solid waste landfills.
• Nitrous Oxide (N2O): agricultural and industrial activities, as
well as during combustion of fossil fuels and solid waste.
• Fluorinated Gases: (Hydrofluorocarbons, perfluorocarbons,
and sulfur hexafluoride): synthetic, powerful greenhouse gases
from a variety of industrial processes.
– Sometimes used as substitutes for ozone-depleting substances
(i.e., CFCs, HCFCs, and halons). Typically emitted in smaller
quantities, but because they are potent GHGs, they are sometimes
2 to as High Global Warming
2
referred
Potential gases (“High GWP
gases”).
GWP = Global Warming Potential
N O x 296 = CO equivalent
CH4 x 21 = CO2 equivalent
Sources: EPA, IPCC
United Nations Educational, Scientific, and Cultural Organization
& Scientific Committee on Problems of the Environment
http://www.icsu-scope.org/unesco/070424%20(w)%20USPB04%20En.pdf
Public Perception ….. Ag is Bad Actor
….. Affecting Air Quality and Water Quality
World Population Growth in More
and Less Developed Countries
Billions
10
9
8
7
20% more people in ~ 20 years
6
Less Developed Regions
5
4
Food, fiber, and fuel demands will continue to increase
3
2
…… what will the environmental impact be?
1
0
1950
More Developed Regions
1970
1990
2010
2030
2050
Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.
http://www.prb.org/Publications/GraphicsBank/PopulationTrends.aspx
Consumption of N Sources
30,000,000
U.S. N Source Consumption
Short tons of fertilizer
25,000,000
Other
20,000,000
Am. thiosulfate
Aqua ammonia
15,000,000
Am. sulfate
Am. nitrate
10,000,000
A. ammonia
5,000,000
Urea
N Soln.
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
-
Year ending June 30
N Consumption in Florida
90,000
70,000
Aq. Amm.
60,000
An. Amm.
50,000
Am. thio.
40,000
Urea
30,000
Other N
20,000
Am. sulfate
10,000
Am. nitrate
UAN sol.
0
1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
Year ending June 30
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
4,000,000
3,500,000
3,000,000
2,500,000
2,000,000
1,500,000
1,000,000
500,000
0
Anhydrous ammonia
Urea + UAN Sol.
Anhydrous ammonia + urea + UAN
Tons of N
Metric tons of N
80,000
Year ending June 30
Gap Between CO2 Emissions of
Developed and Developing Regions (FAO)
CO2 emissions per capita, 2002
Global pressures on developed
countries are increasing
Best Management Practices to Minimize
Greenhouse Gas Emissions
Associated with Fertilizer Use
IPNI Better Crops
article, Issue 4 of 2007
IPNI Review Paper (in press)
Greenhouse Gas Emissions from Cropping Systems
and the Influence of Fertilizer Management
http://www.ipni.net/ppiweb/bcrops.nsf/$webindex/6F2F57CBF1C5209685257394001B2DD0/$file/07-4p16.pdf
Agriculture’s Share of GHG
Emissions is Not Increasing
Agriculture
< 10% of total U.S. GHG
Distribution of GHG Emissions
Estimates of N2O Emissions from
Cropland in 1995 (adapted from IFA/FAO, 2001)
N2O-N emitted
Animal
Manure N
Applied
Area
(million
ha)
Fertilizer
N Applied
Canada
46
1.58
0.21
0.067
0.016
24
U.S.
190
11.15
1.58
0.316
0.112
35
1,436
73.48
20.66
3.150
0.735
23
Region
World
1
total
Fertilizer-induced 1
million tonnes
% of total
Estimated using IPCC emission factor of 1%
Recently published reports suggest terrestrial and aquatic N2O-N
emissions may range from 2 to 5% of “new N”
Food Yield/
Net GWP
.01
.09
.02
.02
.02
.02
.01
.01
Range of N2O Emission Among N
Sources can Vary Greatly
• Report 1 (Stehfast &
Bouwman, 2006)
– 0 to 46% of applied N
• Report 2 (Granli &
Bockman, 1994)
– 0 to 7% of applied N
• Report 3 (Eichner, 1990)
– 0 to 7% of applied N
• Report 1
– Median among N
sources ranged from:
0.26 to 1.56 kg of N/ha
N Rates Above Agronomic Optimum
Can Increase Risk of N2O Emission
Loss of NO3 - N to Water Resources
May Also Impact N2O Emissions
SPARROW - Modeled Estimate of N and P
Discharge in Watersheds of the Mississippi R. Basin
Kg/ha
.01
.01- 0.1
0.1 to 1
1 to 5
5 to 10
>10
How much of the
nitrate-N leached into
shallow groundwater ,
or reaching surface
water is subject to
denitrification and N2O
emission ?
Water Quality/Quantity Best Management Practices for Florida Vegetable and Agronomic Crops. (2005)
Nitrogen Use Efficiency
• “…… estimated NUE for cereal
production ranges from 30 to 35%.”
Improving Nitrogen Use Efficiency for Cereal Production
( 1999
Agronomy Journal 91:357-363)
N Recovery and NUE are Affected
by Other Essential Nutrients
N Loss Consequences Requiring
Management Attention
• Decreased crop production and profitability
– Inefficient land use, reduced performance of other
crop inputs, reduced water use efficiency
• Water resource contamination
– eutrophication: lakes, streams, rivers, estuaries
– groundwater contamination
– coastal water contamination - urea and harmful algal
blooms (neurotoxin poisoning)
• Air pollution
– Ammonia and particulates, nitrous oxide and NOx
(global warming, stratospheric ozone depletion, acid
rain)
Nutrient Use Efficiency and Effectiveness:
Indices of Agronomic and Environmental Benefit
http://www.ipni.net/ipniweb/portal.nsf/0/d58a3c2deca9d7378525731e006066d5/$FILE/Revised%20NUE%20update.pdf
NUE Term
Calculation Reported Examples
PFP - Partial
Y/F
40 to 80 units of cereal grain per unit of N
(Y-Y0)/F
10 to 30 units of cereal grain per unit of N
UH/F
0 to > 1.0 - depends on native soil fertility
and fertility maintenance objectives
<1 in nutrient deficient systems (fertility improvement)
>1 in nutrient surplus systems (under replacement)
Slightly less than 1 to 1 (system sustainability)
(U-U0)/F
0.1 to 0.3 - proportion of P input recovered first year
0.5 to 0.9 - proportion of P input recovered by crops in
factor productivity
AE - Agronomic
Efficiency
PNB - Partial
nutrient balance
(removal to use
ratio)
RE – Recovery
efficiency of
applied nutrient
long-term cropping systems
0.3 to 0.5 - N recovery in cereals-typical
0.5 to 0.8 - N recovery in cereals- best management
F-amt. nutrient applied, Y- yield of harvested portion with applied nutrient, Y0- yield of harvested portion with no
applied nutrient, UH –nutrient content of harvested portion of crop, U –total nutrient uptake in aboveground
biomass with nutrient applied, U0 –total nutrient uptake in aboveground biomass with no nutrient applied
Increased Farmer Interest in
Better N Management
• Increased N costs
• Better crop prices
• Calibration and
verification of
newer technologies
• Improved farmer
skills and availability
of professional
guidance
by crop advisers
“The Market” Nov.1, 2007
Corn grain produced in the U.S. per unit
of fertilizer N used, 1964 to 2005.
1.4
1.15
bu per lb of N
1.3
1.2
*
1.1
1.0
0.9
0.76
0.8
0.7
0.6
*Application rate for 2004 estimated as avg of 2003 & 2005.
0.5
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Since 1975:
51% increase in N efficiency
12% increase in N fertilizer use
Data sources: USDA Ag Chem Use Survey & Annual Crop Production.
Effects of Crop Harvest N Removal on
Net Anthropic Nitrogen Input (NANI)
Figure 1. Net anthropogenic N input (NANI) in major sub-basins of
the Mississippi River Basin estimated from state level statistics.
Source: McIsaac, 2006.
Fertilizer N in FL and GHG Emission
225, 000 x 0.01= 2,250 tons N2O –N emitted
(assuming IPCC 1% factor)
N x 1.57 = 3,533 tons of N2O
N2O x 296 = 1.05 million tons GWP CO2 equivalent
All GHGs in FL in 2007 (Adams, FDEP) :
268 million tons CO2 equivalent
Portion of total that is “fertilizer N induced”
= (1.05/268) x 100 = 0.4% of all GHGs
Source: AAPFCO
• Fertilizer N BMPs can help minimize
potential for residual NO3-N
accumulation & losses
• N source, rate, placement , and
timing …. which may include
–
–
–
–
Urease inhibitors
Nitrification inhibitors
Slow-release materials
Controlled-release materials
• In combination with appropriate, sitespecific cropping system and
conservation practices
– (e.g. conservation tillage, cover crops,
vegetative buffers, managed drainage,
wetlands, bioreactors, etc.)
http://www.floridaagwaterpolicy.com/BestManagementPractices.html
http://www.ipni.net/bettercrops
http://www.fertilizer.org
CONCLUSIONS
• Appropriate fertilizer N helps increase crop
biomass to restore & maintain soil organic
matter (SOM)
• Tillage practices with the least soil
disturbance help maintain SOM
• Intensive crop management can help
minimize GHG emissions, and lower GHG
emission/unit of crop or food produced
• Fertilizer N contributions to agricultural GHG
emissions can range widely, BUT agricultural
emissions are relatively small compared to
other source emissions
• We must continue to strive to improve NUE
Governor Signs Florida
Greenhouse Gas Targets
• MIAMI: Reuters: July 13, 2007
– "The Republican governors of California and Florida gave the
Bush administration the cold shoulder on Friday as Florida set
new limits on greenhouse gas emissions and signed
cooperation pacts on climate change with Germany and
Britain.
• Florida targets call for state utilities to reduce GHG
emissions:
– to 2000 levels by 2017
– to 1990 levels by 2025 and
– by 80 percent of 1990 levels by 2050.
http://lightblueline.org/node/249
January 2, 2008
•California officials say their 2004 law is tougher than the new national
standard. It would have required the auto industry to cut emissions by
one-third in new vehicles by 2016 or reach an average of 36.8 mpg.”
•Twelve other states — CT, ME, MD, MA, NJ, NM, NY, OR, PA, RI, VT,
WA — have adopted the CA emissions standards and the governors of
AZ, CO, FL and UT have said they plan to adopt them. The rules also are
under consideration in Iowa.
•“The auto regulations are a major part of California's global warming law,
which aims to reduce greenhouse gases statewide by 25 percent — to
1990 levels — by 2020. Auto emissions account for about 17 percent of
the state's proposed reductions.”
http://ap.google.com/article/ALeqM5jJH569QSBl-5FfOe4F9liGjADk3gD8TTUJVO0
Dec. 23, 2007
• Ag. Commissioner Charles Bronson- thinks
Florida could grow no
less than 30 percent of
its annual fuel supply.
• Eric Waschman- interim director • He doesn't want farmers
to stop growing their
of the Florida Institute for
staple fruits and
Sustainable Energy at the U. of
vegetables in favor of
Florida – champions making
crops for biofuels.
ethanol from citrus peels and
Instead, they should add
stems because it's taking
extra plantings and use
advantage of waste from a crop
that as an energy source
that was going to be grown and
harvested anyway.
http://www.palmbeachpost.com/news/content/business/epaper/2007/12/23/a1f_biomass_1223.html
http://www.emissionstrading.com/seminar/
QUESTIONS ?
Please Visit the IPNI Website:
www.ipni.net