Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings 10_00-CS.JPG Maize in Oaxaca, Mexico Ch. 10 Agriculture
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Transgenic maize in Oaxaca Corn (maize) originated in Oaxaca, Mexico, 5,500 years ago Oaxaca – center for preservation of cultivars In 2001, transgenes from U.S. appeared in Oaxacan maize Disappeared? Teosinte
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Today, we are producing more food per person Food Production exceeds population, BUT High input required
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Population 9 billion by 2050 Food security = the guarantee of adequate and reliable food supply to all people at all times
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Green Revolution – 1940s -From 1900 to 2000, cultivated area increased 33%, while energy inputs increased 80 times! Requires: -Synthetic fertilizers -Chemical pesticides -Irrigation -Heavy equipment Negative effects: -Pollution -Erosion -Salinization -Desertification Norman Borlaug – father of Green Revolution
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Monocultures – 1 crop
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Herbicides, Insecticides, Fungicides
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Resistance to pesticides Pesticides stop being effective -Evolutionary arms race / pesticide treadmill: chemists increase chemical toxicity to compete with resistant pests
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Biological control Biological control (Biocontrol) = uses a pest’s natural predators to control the pest -Reduces pest populations without chemicals -Ladybugs kill aphids -Bacillus thuringiensis (Bt) = soil bacteria that kills many pests forestencyclopedia.net Ksda.gov
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Biocontrol agents may become pests themselves Removing an invasive biocontrol agent is harder than halting pesticide use ecorpestcontrol.com
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Integrated Pest Management (IPM) uses multiple techniques to suppress (NOT eradicate) pests -Biocontrol -Chemicals, when necessary -Habitat alteration -Crop rotation and transgenic crops -Mechanical pest removal
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Not all insects are pests! Pollination = male plant sex cells fertilize female sex cells -By wind or animals Pollinators include: -Hummingbirds -Bats -Insects Flowers are evolutionary adaptations to attract pollinators
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Genetically modified organisms (GMO or transgenic) Genetic engineering = laboratory manipulation of genetic material Genetically modified organisms = organisms that have been genetically engineered by … Recombinant DNA = DNA created from multiple organisms
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings mono-diglyceride, soya, soja, yuba, TSF (textured soy flour), TSP (textured soy protein), TVP (textured vegetable protein), lecithin, and MSG
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Genetic engineering Benefits -Increased nutritional content -Increased agricultural efficiency -Rapid growth -Disease and pest resistance Negatives -Risks are not yet well understood -Protests from environmental activists, small farmers, and consumer advocates
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Crop diversity and food security How does preserving native varieties protect food security? How do market forces discourage diversity?
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Seed Banks Protect Crop Diversity
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Eating animal products has significant impacts As wealth and commerce increase, so does consumption of meat, milk, and eggs -Global meat production has increased fivefold -Per capita meat consumption has doubled
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Feedlots (factory farms), also called Concentrated Animal Feeding Operations (CAFOs) Concerns?
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Benefits of feedlots: -Greater production of food -Important in countries with high levels of meat consumption, like the U.S. -They take livestock off the land and reduces the impact that they would have on it Drawbacks of feedlots: -Contributions to water and air pollution -Poor waste containment causes outbreaks in disease -Heavy uses of antibiotics to control disease
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Sustainable agriculture = does not deplete soil, pollute water, or decrease genetic diversity -Low-input agriculture = uses smaller amounts of pesticide, fertilizers, growth hormones, water, and fossil fuel energy than industrial agriculture -Organic agriculture = Uses no synthetic fertilizers, insecticides, fungicides, or herbicidesOrganic agriculture -Relies on biological approaches (composting and biocontrol)
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings U.S. Organic
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Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The benefits of organic farming For farmers: -Lower input costs, enhanced income from higher- value products, reduced chemical costs and pollution -Obstacles include the risks and costs of switching to new farming methods and less market infrastructure For consumers: -Concern about pesticide’s health risks -A desire to improve environmental quality -Obstacles include the added expense and less aesthetically appealing appearance of the product
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Organic agriculture succeeds in cities Community gardens = areas where residents can grow their own food In Cuba, over 30,000 people work in Havana’s gardens, which cover 30% of the city’s land -Record yields for 10 crops in
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings “Localvores” = eat only locally grown food Community-supported agriculture (CSA) = consumers pay farmers in advance for a share of their yield Community gardens = areas where residents can grow their own food
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