Ag Production and the Environment

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Ag Production and the Environment

• Text extracted from
• The World Food Problem
• Leathers Foster, 2004

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Global Soil Regions
http//www.wv.nrcs.usda.gov/news/images/06aug_nv/g
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http//www.icrisat.org/gt-aes/TATA/images/concern.
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Erosion

• Soil removed by
• Wind
• water
• Agricultural cause
• Plowing
• bare fields
• Absence of roots

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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
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Physical degradation of soil

• Less porous
• Compaction by
• Heavy machines
• Animals
• Waterlogging
• Roots die
• Due to
• Over irrigation
• Poor drainage

Soil compaction
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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
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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

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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
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David Pimentel

• Believes carrying capacity has already been
  exceeded
• Earth can support 2 billion at high standard of
  living
• Current yields not sustainable

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Julian Simon

• Optimistic about future ag production
• Technology will solve problems
• Drip Irrigation
• Fish Farming
• GMOs for
• Pest resistance
• Drought resistance
• Salt resistance

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Global Warming

• Agriculture contributes to global warming
• CO2 released from plant decomposition
• Co2 80 greenhouse gases
• Methane released from
• Rice paddys
• Cattle Belching
• Nitrous Oxide released from
• Fertilizer use

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Global Warming

• Impact on Agriculture
• Flooding of coastal land
• Affect crop yields
• Increase CO2
• Boosts crop growth
• Increase water-use efficiency
• Increase extreme weather
• Increase insects, disease
• Shift climate zones
• North Africa better
• North America worse

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Bioenergy
http//www.fao.org/clim/docs/CDROM/docs/Bioenergy/
Bioenergy_Facts_and_Figures_01.pdf
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Bioenergy
http//www.fao.org/clim/docs/CDROM/docs/Bioenergy/
Bioenergy_Facts_and_Figures_01.pdf