The Need for Nitrogen The Need for Nitrogen Use Efficiency to ReduceUse Efficiency to ReduceEnvironmental Impacts Environmental Impacts on the Gulf of Mexicoon the Gulf of Mexico

BY BY Dually BertholfDually Bertholf

BAE 4213BAE 4213Spring 2003Spring 2003

Fun FactsFun Factshttp://www.epa.gov/msbasin/index.htm#factshttp://www.epa.gov/msbasin/index.htm#facts

Length of the Mississippi River: 3,705 kilometers (2,302 miles) Length of the Mississippi River: 3,705 kilometers (2,302 miles) Area of Basin: Area of Basin:

3.2 million square kilometers (1.2 million square miles). 3.2 million square kilometers (1.2 million square miles). 40% of the United States 40% of the United States 1/8 of North America 1/8 of North America

Population along the Mississippi Corridor: Population along the Mississippi Corridor: 12 million people live in the 125 counties and parishes that border the 12 million people live in the 125 counties and parishes that border the Mississippi River. Mississippi River.

Amount of water discharged to the Gulf: 612,000 cubic feet per second Amount of water discharged to the Gulf: 612,000 cubic feet per second Provides habitat for Provides habitat for

241 fish species 241 fish species 37 mussel species 37 mussel species 45 amphibians 45 amphibians 50 mammals 50 mammals 40% of the nation's migratory birds40% of the nation's migratory birds

Mississippi River BasinMississippi River Basin

The Mississippi basin, the largest river basin in the United The Mississippi basin, the largest river basin in the United States, forms a wedge of 1,243,000 square miles (3,220,000 States, forms a wedge of 1,243,000 square miles (3,220,000 sq. km.) in the center of the continent, and is made up of three sq. km.) in the center of the continent, and is made up of three major branches, the Mississippi which the middle branch major branches, the Mississippi which the middle branch drains 171,500 square miles (444,300 sq. km.), the Missouri drains 171,500 square miles (444,300 sq. km.), the Missouri drains approximately 530,000 square miles (1,373,000 sq. drains approximately 530,000 square miles (1,373,000 sq. km.), and the Ohio which drains 202,000 square miles km.), and the Ohio which drains 202,000 square miles (523,000 sq. km.). Below the Ohio, the lower Mississippi (523,000 sq. km.). Below the Ohio, the lower Mississippi gathers water from several other smaller basins, namely the gathers water from several other smaller basins, namely the Arkansas and the Red River. Arkansas and the Red River.

Mississippi River Basin Cont.Mississippi River Basin Cont.

In 1990, Mississippi Basin farmers applied 21 billion In 1990, Mississippi Basin farmers applied 21 billion

pounds of fertilizer.pounds of fertilizer. http://www.sierraclub.org/ecoregions/missbasin.asphttp://www.sierraclub.org/ecoregions/missbasin.asp A 12 percent reduction in nitrogen fertilizer use could A 12 percent reduction in nitrogen fertilizer use could

have a 33 percent reduction in the nitrate flux in the have a 33 percent reduction in the nitrate flux in the

Mississippi River and Gulf of Mexico.Mississippi River and Gulf of Mexico. http://www.newswise.com/articles/2001/11/NITROGEN.UIL.htmlhttp://www.newswise.com/articles/2001/11/NITROGEN.UIL.html

Total nitrogen flux into the Mississippi river basin Total nitrogen flux into the Mississippi river basin has been estimated to have tripled over the last 35 has been estimated to have tripled over the last 35

years.years. http://webserver.cr.usgs.gov/hypoxia/ http://webserver.cr.usgs.gov/hypoxia/

Mississippi River InformationMississippi River Information

It drains 41 percent of the contiguous U.S.It drains 41 percent of the contiguous U.S. Covers 55 percent of U.S. agricultural lands.Covers 55 percent of U.S. agricultural lands. Includes 33 major river systems and 207 estuaries.Includes 33 major river systems and 207 estuaries. Includes 27 percent of U.S. population.Includes 27 percent of U.S. population. Includes about 80 percent of U.S. corn and soybeanIncludes about 80 percent of U.S. corn and soybean

acreages, and much of the cotton, rice, sorghum,acreages, and much of the cotton, rice, sorghum,

wheat, and forage lands.wheat, and forage lands.

Mississippi River Information Cont.Mississippi River Information Cont.

Is the source of 72 percent of U.S. harvested shrimp,Is the source of 72 percent of U.S. harvested shrimp,

66 percent of the harvested oysters, and 16 percent of66 percent of the harvested oysters, and 16 percent of

the U.S. commercial fish harvestthe U.S. commercial fish harvest Has fisheries valued annually at over $700 million atHas fisheries valued annually at over $700 million at

dockside. Its commercial and recreational fisheriesdockside. Its commercial and recreational fisheries

have a combined value of $2.4 billion per year. have a combined value of $2.4 billion per year.

DefinitionsDefinitions

HypoxiaHypoxia: Hypoxia refers to dissolved oxygen : Hypoxia refers to dissolved oxygen concentrations less than 2 mg/L (milligrams per liter). concentrations less than 2 mg/L (milligrams per liter). Hypoxia can cause stress or death in bottom-dwelling Hypoxia can cause stress or death in bottom-dwelling organisms that can not leave the zone. Hypoxia is caused organisms that can not leave the zone. Hypoxia is caused primarily by excess nitrogen delivered from the primarily by excess nitrogen delivered from the Mississippi River in combination with seasonal Mississippi River in combination with seasonal stratification of Gulf waters. Nitrogen promotes algal and stratification of Gulf waters. Nitrogen promotes algal and attendant zooplankton growth. The associated organic attendant zooplankton growth. The associated organic matter sinks to the bottom where it decomposes, matter sinks to the bottom where it decomposes, consuming available oxygen. Stratification of fresh and consuming available oxygen. Stratification of fresh and saline waters prevents oxygen replenishment by mixing of saline waters prevents oxygen replenishment by mixing of oxygen-rich surface water with oxygen-depleted bottom oxygen-rich surface water with oxygen-depleted bottom water. water.

Definitions Cont.Definitions Cont. EutrophicationEutrophication—The process of being enriched in—The process of being enriched in dissolved nutrients, especially nitrate (NO3) anddissolved nutrients, especially nitrate (NO3) and phosphate. Eutrophication can enhance phytoplanktonphosphate. Eutrophication can enhance phytoplankton (microscopic, passively floating plants) growth.(microscopic, passively floating plants) growth. This increased growth can cause an increase inThis increased growth can cause an increase in organic matter deposition. As the organic matterorganic matter deposition. As the organic matter from dead phytoplankton and fecal residues fromfrom dead phytoplankton and fecal residues from zooplankton (which feed on the phytoplankton)zooplankton (which feed on the phytoplankton) drops to the bottom waters, microorganisms decomposedrops to the bottom waters, microorganisms decompose it and deplete dissolved O2 from the water.it and deplete dissolved O2 from the water. drops to the bottom waters, microorganisms decomposedrops to the bottom waters, microorganisms decompose it and deplete dissolved O2 from the water.it and deplete dissolved O2 from the water.

N SourceN Source Short Tons

Mineralized soil N 7,497,404

Fertilizer N 7,497,094

Legume N fixation 4,445,155

All manure N 3,582,911Atmospheric wet and

dry deposition of nitrate-N 1,461,656

Atmospheric deposition of ammonium-N

663,497

Municipal point sources of N

221,266

Industrial point sources of N

94,370

http://www.ppi-ppic.org/ppiweb/ppinews.nsf/$webcontents/A1A0DBBD5BBAF52185256903006E5E90/$file/99176-http://www.ppi-ppic.org/ppiweb/ppinews.nsf/$webcontents/A1A0DBBD5BBAF52185256903006E5E90/$file/99176-Hypoxia.pdfHypoxia.pdf

Nflux = 0.049*F2 + 36*Q - Nflux = 0.049*F2 + 36*Q - 0.094*R1 0.094*R1

NfluxNflux:: Nitrate flux to the Gulf, in metric tons Nitrate flux to the Gulf, in metric tons per year.per year.

F2F2: Fertilizer use in the entire basin 2 years : Fertilizer use in the entire basin 2 years previous, in metric tons.previous, in metric tons.

QQ: Current year mean annual discharge to the : Current year mean annual discharge to the Gulf, in cubic meters per second.Gulf, in cubic meters per second.

R1R1: Nitrogen residual for the previous year, : Nitrogen residual for the previous year, in metric tons. in metric tons.

http://ks.water.usgs.gov/Kansas/pubs/fact-sheets/fs.135-00.html

Nflux = 0.049*F2 + 36*Q - 0.094*R1Nflux = 0.049*F2 + 36*Q - 0.094*R1

R² of 0.89R² of 0.89 http://ks.water.usgs.gov/Kansas/pubs/fact-sheets/fs.135-00.htmlhttp://ks.water.usgs.gov/Kansas/pubs/fact-sheets/fs.135-00.html

Hypoxia in the Gulf of MexicoHypoxia in the Gulf of Mexico Hypoxic waters are distributed from shallow depths near shore Hypoxic waters are distributed from shallow depths near shore

(4 to 5 m) to as deep as 60 m, but are present more typically (4 to 5 m) to as deep as 60 m, but are present more typically between 5 and 30 m. Hypoxia occurs mostly in the lower between 5 and 30 m. Hypoxia occurs mostly in the lower water column but encompasses as much as the lower half to water column but encompasses as much as the lower half to two-thirds of the column. two-thirds of the column. http://www.nos.noaa.gov/products/hypox_t1final.pdf pg.17 par.5 http://www.nos.noaa.gov/products/hypox_t1final.pdf pg.17 par.5

Hypoxia covers broad regions of the shelf for extended Hypoxia covers broad regions of the shelf for extended periods in mid-summer. In 1985–92, the midsummer bottom periods in mid-summer. In 1985–92, the midsummer bottom areal extent of hypoxic waters (< 2 mg/l O2, or ppm) averaged areal extent of hypoxic waters (< 2 mg/l O2, or ppm) averaged 8,000–9,000 km2; in 1993– 97 it increased to 16,000–18,000 8,000–9,000 km2; in 1993– 97 it increased to 16,000–18,000 km2. The estimated extent was 12,500 km2 in mid-summer of km2. The estimated extent was 12,500 km2 in mid-summer of 1998. 1998. http://www.nos.noaa.gov/products/hypox_t1final.pdf pg.17 par.3 http://www.nos.noaa.gov/products/hypox_t1final.pdf pg.17 par.3

Hypoxia in the Gulf of Mexico Cont.Hypoxia in the Gulf of Mexico Cont.

Hypoxia occurs not only at the bottom near the Hypoxia occurs not only at the bottom near the sediments, but well up into the water column (see sediments, but well up into the water column (see Sections 3.2 and 3.4). Depending on the depth of the Sections 3.2 and 3.4). Depending on the depth of the water and the location of the pycnocline(s), hypoxia water and the location of the pycnocline(s), hypoxia may encompass from 10% to over 80% of the total may encompass from 10% to over 80% of the total water column, but normally encompasses 20–50%. water column, but normally encompasses 20–50%. Hypoxia may reach to within 2 m of the surface in a Hypoxia may reach to within 2 m of the surface in a 10-m water column, or to within 6 m of the surface in 10-m water column, or to within 6 m of the surface in a 20-m water column. Anoxic bottom waters can a 20-m water column. Anoxic bottom waters can occur, along with the release of toxic hydrogen occur, along with the release of toxic hydrogen sulfide from the sediments. sulfide from the sediments. http://www.nos.noaa.gov/products/hypox_t1final.pdf pg.24 http://www.nos.noaa.gov/products/hypox_t1final.pdf pg.24

par.2par.2

Factors That Influence Hypoxia Factors That Influence Hypoxia Levels in the Gulf of MexicoLevels in the Gulf of Mexico

Changes in precipitation patterns and quantitiesChanges in precipitation patterns and quantities within the Mississippi River Basinwithin the Mississippi River Basin Increased Mississippi River flow and fresh waterIncreased Mississippi River flow and fresh water stratification over salt waterstratification over salt water Complex interactions among marine organismsComplex interactions among marine organisms Increased or sustained large fisheries harvestsIncreased or sustained large fisheries harvests Gulf storms and hurricanesGulf storms and hurricanes Tidal currents and their characteristics (temperature,Tidal currents and their characteristics (temperature, circulation, etc.)circulation, etc.) Loss of coastal wetlands (25-35 square miles/year inLoss of coastal wetlands (25-35 square miles/year in Louisiana alone)Louisiana alone) Nutrients from re-suspended N sediments andNutrients from re-suspended N sediments and upwelling off the Yucatan Peninsula upwelling off the Yucatan Peninsula

ThoughtsThoughts

Increase Nitrogen Use Efficiency by stressing the Increase Nitrogen Use Efficiency by stressing the importance to the plant breeders, so they will develop importance to the plant breeders, so they will develop more efficient breeds of plants.more efficient breeds of plants.

Use site specific farming practices to only apply Use site specific farming practices to only apply fertilizers, insecticides, and herbicides.fertilizers, insecticides, and herbicides.

Only apply what is needed for the specific areas and Only apply what is needed for the specific areas and at the appropriate time.at the appropriate time.

With the help of new technologies and the With the help of new technologies and the willingness of the people we will have a safe and willingness of the people we will have a safe and productive future. productive future.

Questions?Questions?

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References Cont.References Cont. http://www.fumento.com/hypoxiacolumn.htmlhttp://www.fumento.com/hypoxiacolumn.html http://www.cop.noaa.gov/Fact_Sheets/NGOMEX.htmhttp://www.cop.noaa.gov/Fact_Sheets/NGOMEX.htm http://www.ncat.org/nutrients/hypoxia/hypoxia.htmlhttp://www.ncat.org/nutrients/hypoxia/hypoxia.html http://www.capitolink.com/sections/issues/hypoxia.htmlhttp://www.capitolink.com/sections/issues/hypoxia.html http://www.beachbrowser.com/Archives/Environment/August-99/HYPOXIA-IN-http://www.beachbrowser.com/Archives/Environment/August-99/HYPOXIA-IN-

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References Cont.References Cont. http://precision.agri.umn.edu/Literature/Abstracts00/156.htmlhttp://precision.agri.umn.edu/Literature/Abstracts00/156.html http://www.extension.umn.edu/distribution/cropsystems/DC6125.htmlhttp://www.extension.umn.edu/distribution/cropsystems/DC6125.html http://www.hort.purdue.edu/rhodcv/hort640c/nuse/nu00007.htmhttp://www.hort.purdue.edu/rhodcv/hort640c/nuse/nu00007.htm http://search.yahoo.com/search?http://search.yahoo.com/search?

p=nitrogen+use+efficiency&b=61&hc=&hs=1&xargs=0p=nitrogen+use+efficiency&b=61&hc=&hs=1&xargs=0 http://n2001.esa.org/n2004.htmlhttp://n2001.esa.org/n2004.html http://www.sarep.ucdavis.edu/newsltr/v11n1/technical1.htmhttp://www.sarep.ucdavis.edu/newsltr/v11n1/technical1.htm http://www.ntechindustries.com/http://www.ntechindustries.com/ http://ag.arizona.edu/swes/research/program5.htmhttp://ag.arizona.edu/swes/research/program5.htm http://www.cropsci.uiuc.edu/research/pubs/n-rate-2001.htmlhttp://www.cropsci.uiuc.edu/research/pubs/n-rate-2001.html http://frec.cropsci.uiuc.edu/1999/http://frec.cropsci.uiuc.edu/1999/ http://esa.sdsc.edu/hypox5.htmhttp://esa.sdsc.edu/hypox5.htm http://ks.water.usgs.gov/Kansas/pubs/fact-sheets/fs.135-00.fig5.gif http://ks.water.usgs.gov/Kansas/pubs/fact-sheets/fs.135-00.fig5.gif

References Cont.References Cont. http://www.epa.gov/msbasin/economy.htmhttp://www.epa.gov/msbasin/economy.htm http://www.epa.gov/msbasin/actionplan.htmhttp://www.epa.gov/msbasin/actionplan.htm http://wwwrcolka.cr.usgs.gov/midconherb/descriptions.htmlhttp://wwwrcolka.cr.usgs.gov/midconherb/descriptions.html http://wwwrcolka.cr.usgs.gov/midconherb/hyp.rpts.htmlhttp://wwwrcolka.cr.usgs.gov/midconherb/hyp.rpts.html http://wwwrcolka.cr.usgs.gov/midconherb/links.htmlhttp://wwwrcolka.cr.usgs.gov/midconherb/links.html http://umbc7.umbc.edu/~tbenja1/baumann/mod2.html http://umbc7.umbc.edu/~tbenja1/baumann/mod2.html http://www.usda.gov/nass/pubs/agstats.htmhttp://www.usda.gov/nass/pubs/agstats.htm http://www.sierraclub.org/ecoregions/missbasin.asphttp://www.sierraclub.org/ecoregions/missbasin.asp

http://wwwrcolka.cr.usgs.gov/midconherb/st.louis.hypoxia.htmlhttp://wwwrcolka.cr.usgs.gov/midconherb/st.louis.hypoxia.html http://ca.umces.edu/ian/commonground/missnflux.pdfhttp://ca.umces.edu/ian/commonground/missnflux.pdf http://www.ppi-far.org/ppiweb/usams.nsf/$webindex/http://www.ppi-far.org/ppiweb/usams.nsf/$webindex/

014300E14A66969186256C40007D7A82?014300E14A66969186256C40007D7A82?opendocument&navigator=home+page opendocument&navigator=home+page

References Cont.References Cont. http://www.newswise.com/articles/2001/11/NITROGEN.UIL.htmlhttp://www.newswise.com/articles/2001/11/NITROGEN.UIL.html http://www.ppi-ppic.org/ppiweb/ppinews.nsf/$webcontents/http://www.ppi-ppic.org/ppiweb/ppinews.nsf/$webcontents/

A1A0DBBD5BBAF52185256903006E5E90/$file/99176-Hypoxia.pdfA1A0DBBD5BBAF52185256903006E5E90/$file/99176-Hypoxia.pdf http://www.nstl.gov/research/onepage/onepagni.htmlhttp://www.nstl.gov/research/onepage/onepagni.html http://ks.water.usgs.gov/Kansas/pubs/fact-sheets/fs.135-00.htmlhttp://ks.water.usgs.gov/Kansas/pubs/fact-sheets/fs.135-00.html