Title: Nitrogen Issues Speaker: Bill...
Transcript of Title: Nitrogen Issues Speaker: Bill...
Title: Nitrogen Issues Speaker: Bill Pan
online.wsu.edu
Unit 2, Lesson 2:
Nitrogen, the Two-Edged Sword
Food production
Environmental ,
safety, health
issues
Learning Objectives
• The Dichotomy: Credited with saving millions of lives, ammonia synthesis was also created for war time purposes. Today it is also being linked to some of the most pressing environmental and safety problems.
Nutrient Management Issues
Nutrient
Management
Resource
Management
Crop Yield and
Quality
Enviro
nm
en
tal
Pro
tectio
n
So
il
Qu
ality
Carl Bosch (1874-1940)
The perfect catalyst, 1910
Large-scale production, 1913
Ammonia to nitrate, 1914
Nobel Prize in Chemistry, 1931
”chemical high pressure methods”
Fritz Haber (1868-1934) Began work on NH3, 1904
First patent, 1908
Commercial-scale test, 1909
Developed Cl2 gas production, 1914
Nobel Prize in Chemistry, 1918 ”for the synthesis of ammonia from its elements”
Smil, 2001
Industrial N Fertilizer
Production
Haber-Bosch
1200C, 500atm
3H + N 2NH 2 2 3
CO2, N2O (Greenhouse gases)
Natural gas
CH4
Inorganic N Fertilizer has been
largely responsible for
increased crop yields of the
Green Revolution
Haber-Bosch: Synthesis of Reactive N
0
1
2
3
4
5
6
7
1750 1800 1850 1900 1950 2000 2050
0
50
100
150
200
Humans Haber Bosch
Legumes/Rice NOx emissions
Galloway JN and Cowling EB. 2002; Galloway et al., 2002a
N-Discovered
N-Nutrient
BNF
Haber-Bosch
N2 + 3H2 2NH3
Hu
man
Po
pu
lati
on
, b
illi
on
s
Reactiv
e N
itrog
en
, Tg
DHumans = D Reactive N
Harvested Crop Acreage
Per Person in the World
0
0.05
0.1
0.15
0.2
0.25
Ye
ar
195
1
195
7
196
3
196
9
197
5
198
1
198
7
199
3
A Plateau in Grain Production
World Grain Production
0
50
100
150
20019
60
1966
1972
1978
1984
1990
Year
Grai
n (m
illion
tons
)
Per Capita Grain Production
0
100
200
300
400
Ye
ar
195
1
195
7
196
3
196
9
197
5
198
1
198
7
199
3
Grain (kg/person)
Post World War II Adoption of
Commercial Fertilizers
Stonehenge
1960 1980 2000 2020Fe
rtili
ze
r N
utr
ien
t U
se
(m
illio
n to
ns)
0
10
20
30
40
50
60
70East Asia w/China)
N. Am., Europe
South Asia (w/India)
Latin America
Near East/North Africa
Subsaharan Africa
Source: FAO, World Agriculture: towards 2015/2030
~60% of nutrients are used on cereal crops,
predominantly wheat, rice, maize
Source: International Fertilizer Industry Association
Shifting Worldwide Distribution of Nitrogen Production
Current trends: http://www.fertilizer.org/ifa/statistics/pit_public/pit_public_statistics.asp
Global Competition is placing
increasing emphasis on crop quality
M. Pidwirny. Physicalgeography.net. U. British Columbia
Changes in Spatial Relationships of
Trophic Pyramid (modified from Magdoff et al., 1997)
plants
animals
humans
soil
Industrial Agriculture Primitive agriculture
plants
animals
humans
soil
plants
animals
humans
soil
Urbanization
N related environmental issue #1-
health concerns
• Nitrate contamination of groundwater
– methemoglobinemia (blue baby syndrome), cancer, diabetes
– EPA maximum limits: 10 ppm nitrate-N (10 mg/L) or 45 ppm nitrate, EU 0.1 mg nitrite-N/L
– BUT, meat preservative, antibacterial, lowers blood pressure
– Treatment systems are available but expensive
Nitrate in Drinking Water
in the Columbia Plateau
Fertilizer Use in the Columbia
Plateau
China’s N Contamination Problem
Ground water nitrate above critical health standards:
•50% in northern China
•21% in Shaanxi Province
•30% in Guandong Province
Source: Yang et al., 2004, Agron. J. 1039-1049.
Atmospheric wet N deposition
~11 Tg N (12 kg N/ha/yr) –Xing, In Cowling et al., 2002.
Calculate-compare N intake from
• 1 liter of 10 ppm nitrate-N (NO3-N)
• ¼ lb preserved meat with 100 ppm nitrite-N
(NO2-N)
• 6 oz lettuce with 3500 ppm NO3 in the cell
sap…assume lettuce is 85% water.
• 5 g sensitive toothpaste with 5% KNO3 wet wt
• Dead zone-algal
blooms and decay
cause oxygen
depletion of Gulf of
Mexico – see the
far-reaching
watershed of the
Mississippi River
N related environmental issue #2
Nitrate concentrations in the
lower Mississippi
Total N Flux Through the
Lower Mississippi
Worldwide Distribution of
Hypoxic Coastal Waters
These “dead zones” are associated with major population areas
or nutrient laden watersheds
Egypt
http://www.earth-policy.org/
Issue #3: Non-renewable resource
use • Reliance on natural
gas for Haber-Bosch process
• 3-4% of natural gas used for fertilizer production
• N price increases are driving farmers out of business
Issue #4 Safety in
transportation and handling
Issue #5: Soil Quality
How has the advent of inorganic N fertilizers affected soil
quality?
-more crop residues produced, builds soil organic matter
-Conversely, N fertilizers allow for less diverse crop rotations,
green manures not required.
-high levels of ammonium, nitrite can temporarily reduce
microbial activity.
Inorganic vs. Organic N
Sources • What are the pros and
cons?
• Use on farm resources
• Multiple benefits of organic sources on nutrient availability, soil quality
• Costs: storage, transportation, application
Issue #6: Public safety: Illegal Uses
of N fertilizers
• Anhydrous Ammonia Thefts and Releases Associated with Illicit Methamphetamine Production --- 16 States, January 2000--June 2004 http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5414a4.htm
• Anhydrous ammonia, a colorless gas with a pungent, suffocating fumes, is used primarily as an agricultural fertilizer and industrial refrigerant (1). Anhydrous ammonia is also a key ingredient for illicit methamphetamine (meth) production in makeshift laboratories. Exposure to anhydrous ammonia can be immediately dangerous to life or health (1,2). Anhydrous ammonia generally is not available for sale to the public; states require a license for purchase. Because of this, many illicit meth producers (i.e., "cookers") resort to stealing anhydrous ammonia. If released into the environment, anhydrous ammonia can cause acute injuries to emergency responders, the public, and the cookers themselves. In addition, when handled improperly, anhydrous ammonia can be explosive and deadly. This report describes examples of anhydrous ammonia thefts associated with illicit meth production, summarizes ammonia theft events reported to the Agency for Toxic Substances and Disease Registry (ATSDR), and suggests injury prevention recommendations, such as installing valve locks or fencing on unattended tanks and donning appropriate personal protective equipment (PPE) when responding to releases.
• ATSDR maintains the Hazardous Substances Emergency Events Surveillance (HSEES) system to collect and analyze data about the public health consequences (i.e., morbidity, mortality, and evacuations) of hazardous substance--release events*. The information in this report is based on events reported to HSEES from 16 state health departments† during January 1, 2000--June 30, 2004§.
• Ammonium nitrate use in explosives-e.g. Sterling Hall, U WI, 1971; Oklahoma City, 1995
– Commercial ban as fertilizer due to heightened security concerns after 9/11
Issue #7: Air pollutants and
Greenhouse Gases: Ammonia and
N oxide emissions • Feedlot, manure storage, compost
pile
• Crop field emissions
• Water treatment by denitrification
–Food processing
–Manure lagoons
–Sewage treatment
Government Intervention:
Nutrient Management Plans • CAFO (confined animal feeding operations) in
WA http://agr.wa.gov/FoodAnimal/Livestock-Nutrient/CAFONutrientMgmtPlans.aspx
Stakeholders in the
Nutrient Management
• Farmers
• Public
• Fertilizer industry
• Government
• Universities