360 likes | 478 Views
Ag Production and the Environment. Text extracted from The World Food Problem Leathers & Foster, 2004. http://www.lastfirst.net/images/product/R004548.jpg. Erosion. Soil removed by Wind water Agricultural cause: Plowing bare fields Absence of roots. Wind Erosion.
E N D
Ag Production and the Environment Text extracted from The World Food Problem Leathers & Foster, 2004 http://www.lastfirst.net/images/product/R004548.jpg
Erosion • Soil removed by • Wind • water • Agricultural cause: • Plowing • bare fields • Absence of roots
Wind Erosion http://soils.usda.gov/use/worldsoils/mapindex/eroswind.jpg
Water Erosion http://soils.usda.gov/use/worldsoils/landdeg/papers/ersnfig1.jpg
Chemical Degradation of Soil • Nutrient depletion • Especially if same crop grown every year • Salinization • Irrigation with low levels of salt • Salt build up when dries • Acidification • Too much fertilizer • Drainage problems • Pollutants • Oil • Pesticides Salinization http://www.ciseau.org/cds_upload/1118333201256_Thailande.png
Physical degradation of soil • Less porous • Compaction by • Heavy machines • Animals • Water logging • Roots die • Due to • Over irrigation • Poor drainage Soil compaction http://www.dpi.vic.gov.au/CA25677D007DC87D/LUbyDesc/Pugged+soil/$File/PUGGED-1.jpg
Extent of Land Degradation • 38% total cropland degraded worldwide • 2 billion hectares • 83% by erosion • 12% chemical • 5% physical • 5-10 million new hectares • degraded each year • New land must be put into production to compensate • Generally poor quality Overgrazed degraded soil http://farm3.static.flickr.com/2097/2138777732_5aa323c591.jpg?v=0
Irrigation Problems • Water Quality degradation • Salt-water intrusion in coastal areas due to lower water table • Leeches salt into groundwater: unusable • Runoff carries fertilizer, pesticide residues • Land degradation: • SoilErosion • Waterlogging • Salinization • acidification Irrigation in Uzbekistan http://www.fao.org/docrep/009/a0409e/A0409E15.jpg
Ag Chemicals • Can lead to • Land degradation • Water pollution • Health problems • Chemical manufacture can be dangerous • Explosion at fertilizer plant in Bhopal India in 1984 • Killed thousands Union Carbide Chemical Plant, Bhopal India
Fertilizer Runoff: Hypoxia Hypoxia Dead zone in rivers, lakes, oceans N and P fertilizer runoff cause algae growth Algal bloom removes dissolved oxygen Result: nothing grows
Carrying Capacity • How many people can earth support? • Carrying capacity • Limitations on • Agricultural land • Fresh water • Waste assimilation http://www.lunaroutpost.com/gallery/earth/images/globe_west_2048.tif.jpg
David Pimentel • Believes carrying capacity has already been exceeded • Earth can support 2 billion • at high standard of living • Current yields not sustainable http://ipmworld.umn.edu/vitae/mug/pdmug.gif
Julian Simon • Optimistic about future ag production • Technology will solve problems • Drip Irrigation • Fish Farming • GMOs for • Pest resistance • Drought resistance • Salt resistance http://www.indefenceofliberty.org/admin/thumbnail/julian.jpg
Fish: the Blue Revolution • World fish stocks fully exploited • No future increases in wild capture • Aquaculture increasing • Developing nations • China • Developing nations by 2020 • 79% World population • 77% World fish consumption http://photos.mongabay.com/07/world_fish_1950-2000-400.jpg http://www.ifpri.org/pressrel/2003/20031002.htm http://news.bbc.co.uk/nol/shared/spl/hi/pop_ups/04/sci_nat_feeding_the_world/img/5.jpg http://photos.mongabay.com/07/world_fish_1950-2000-400.jpg
Fish: the Blue Revolution http://www.theglobaleducationproject.org/earth/image.php?image=f-fisheries-map-lg.gif&title=global%20aquaculture
Global Warming • Agriculture contributes to global warming: • CO2 released from plant decomposition • CO2 = 80% greenhouse gases • No-till Ag releases less CO2 • Methane released from rice paddies • Methane: 23 x warming impact of CO2 • Nitrous Oxide (NO) released from fertilizer use • NO: 296 x warming impact of CO2 http://picturethis.pnl.gov/PictureT.nsf/All/6GPMKU?opendocument
Global Warming • Livestock contribute to GW • Produce 18% of total greenhouse gasses • (Cars, Airplanes, Trains, Boats total 13%) • 1.3 billion cattle in world • Occupy 1/3 earth’s landmass • 20 lb CO2 produced per pound of beef • Cattle Belching produces methane • 200L/d/cow methane • 5% of planet’s greenhouse gasses • Manure produces Nitrous Oxide (NO) • Deforestation to support livestock • Grazing land • Crop land to grow feed • 70% of former forest in Latin America is grazing land http://www.theage.com.au/ffximage/2008/01/22/cow2_wideweb__470x277,0.jpg
Global Cattle Distribution All densities are in heads per square Kilometer. http://agtr.ilri.cgiar.org/Maps/distributionMaps/Species/Cattle.htm
Global Cattle Distribution Global livestock production is projected to double by 2050
http://facweb.furman.edu/~mhuntsberger/blogs/com40spring08/b/wp-content/uploads/global_warming_predictions_map_2.jpghttp://facweb.furman.edu/~mhuntsberger/blogs/com40spring08/b/wp-content/uploads/global_warming_predictions_map_2.jpg
Ice melt in Greenland http://heartspring.net/images/greenland_ice_melt.jpg
Global Warming • Impact on Agriculture: • Flooding of coastal land • ½ of world population lives within 120 miles of the coast • Affect crop yields • Increase CO2 • Boosts crop growth • Increase water-use efficiency • Increase extreme weather • Increase insects, disease • Shift climate zones • Northern regions better • Tropical regions worse • Developing countries
Impact on Agriculture http://www.imf.org/external/pubs/ft/fandd/2008/03/images/cline5.gif
Impact on Agriculture http://earthtrends.wri.org/images/climate_change_agricultural_potential.jpg
USA biggest CO2 emitter http://www.hyperhistory.com/online_n2/connections_n2/climate_n2/emissions.gif
Ethical Issue • Global warming is caused primarily by CO2 • from industrial development in the first world • Is it morally acceptable that the developing world will suffer more negative effects from global warming • Without having benefited from the fossil fuels that caused the problem. http://jcwinnie.biz/wordpress/imageSnag/468_pollution.jpg
Solving Global Warming http://www.zzilch.com/blog/wp-content/uploads/2008/03/combating-global-warming-map.jpg
Bioenergy • Potential: • Reduce CO2 emissions • Plants fix CO2 • Sustainable • If use perrennial switchgrass • Profits for farmers • Worldwide • Energy for poor • Worldwide http://www.iowaswitchgrass.com/__images/Switchgrass-Graphic_800.jpg
Bioenergy Problems • Competes with food production • Agricultural land diverted • Food prices rise worldwide • Hurts poor hardest • Undernutrition • Ethanol from maize increases CO2 production • Farming uses fossil fuel • Less soybeans planted in U.S. • Tropical forests destroyed to plant soybeans in Brazil. • Net loss of ability to fix CO2 • Biodiesel from oil palm and soybeans destroys rainforests • Oil palm plantations in S.E. Asia • Soybean planting in Brazil Oil Palm Plantation, Indonesia http://image.guim.co.uk/Guardian/environment/gallery/2008/apr/01/biofuels/GD5160468@This-undated-photo-sh-509.jpg
http://media.townhall.com/Townhall/Car/b/20080421RZ1AP-BiofuelGauge.jpghttp://media.townhall.com/Townhall/Car/b/20080421RZ1AP-BiofuelGauge.jpg
http://cranialcavity.files.wordpress.com/2008/04/ethanolcomic.jpghttp://cranialcavity.files.wordpress.com/2008/04/ethanolcomic.jpg
Bioenergy benefits and challenges http://www.fao.org/clim/docs/CDROM/docs/Bioenergy/Bioenergy_Facts_and_Figures_01.pdf
Bioenergy plusses and minuses http://www.fao.org/clim/docs/CDROM/docs/Bioenergy/Bioenergy_Facts_and_Figures_01.pdf