Food, Soil, and Pest Management

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Food, Soil, and Pest Management

• Chapter 12

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How Can We Protect Crops from Pests More
Sustainably?

• We can sharply cut pesticide use without
  decreasing crop yields by using a mix of
  cultivation techniques, biological pest controls,
  and small amounts of selected chemical pesticides
  as a last resort (integrated pest management).

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Nature Controls the Populations of Most Pests

• What is a pest interferes with human welfare
• Natural enemiespredators, parasites, disease
  organismscontrol pests
• In natural ecosystems
• In many polyculture
• agroecosystems

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We Use Pesticides to Try to Control Pest
Populations

• Pesticides
• Insecticides insects killers
• Herbicides weed killers
• Fungicides fungus killers
• Rodenticides rat and mouse killers
• Herbivores overcome plant defenses through
  natural selection coevolution

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We Use Pesticides to Try to Control Pest
Populations

• First-generation pesticides-natural chemicals
  from plants
• Second-generation pesticides
• Paul Muller DDT Nobel Prize 1948
• Benefits versus harm
• Broad-spectrum agents toxic to many pests and
  non-pest species. Chlorinated hydrocarbons DDT,
  organophosphates malathion, parathion
• Selective or narrow spectrum agents -
• Persistence length of time they remain deadly
  in the environment for years, biologically
  magnified in food webs

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Individuals Matter Rachel Carson

• Biologist DDT use was increasing to control
  mosquitoes
• Silent Spring - 1962
• Potential threats of uncontrolled use of
  pesticides
• Gave impetus to the US environmental movement

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Modern Synthetic Pesticides Have Several
Advantages

• Save human lives prevented deaths from malaria,
  typhus and bubonic plague at least 7 million
  people
• Increases food supplies and profits for farmers
  protect 55 of the worlds food supply. Profit
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• Work quickly, long shelf life, easily shipped and
  applied
• Health risks are very low relative to their
  benefits
• New pest control methods safer and more effective

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Modern Synthetic Pesticides Have Several
Disadvantages

• Accelerate the development of genetic resistance,
  5 to 10 years, sooner in the tropics
• Financial treadmill
• Kill natural predators and parasites that help
  control
• Only 0.1-2 of the pesticide applied by aerial or
  ground spraying reaches the target pest. Rest
  pollutes air, water, harm wild life, affect
  human health
  
  
  
• Expensive for farmers
• Some insecticides kill natural predators and
  parasites that help control the pest population
• Pollution in the environment
• Some harm wildlife
• Some are human health hazards

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Modern Synthetic Pesticides Have Several
Disadvantages

• David Pimentel Pesticide use has not reduced
  U.S. crop loss to pests
• Loss of crops is about 31, even with 33-fold
  increase in pesticide use
• High environmental, health, and social costs with
  use, 5-10 in damages for every 1 spent
• Use alternative pest management practices could
  halve the use of chemical pesticides on 40 major
  US crops
• Pesticide industry refutes these findings
• Campbell soup tomatoes in Mexico, Rice in
  Indonesia, Sweden

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Glyphosate-Resistant Crop Weed Management System
A Dilemma

• Best-selling herbicide (Roundup), Monsanto
• Advantages does not harm living things,
  degrades into harmless substances within weeks
• Disadvantages - resistant weeds , expensive to
  develop other pesticides

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Case Study Ecological Surprises

• 1955 Dieldrin sprayed to control mosquitoes
• Malaria was controlled
• Dieldrin didnt leave the food chain
• Domino effect of the spraying
• Happy ending

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Laws and Treaties Can Help to Protect Us from the
Harmful Effects of Pesticides

• U.S. federal agencies
• EPA
• USDA
• FDA
• Effects of active and inactive pesticide
  ingredients are poorly documented
• Circle of poison, boomerang effect residues of
  banned chemicals exported to other countries may
  come back on food, winds carry persistent
  pesticides such as DDT

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International Treaties

• 1998 50 countries developed treaty that
  requires exporting countries to have consent from
  importing countries for exports of 22 pesticides
  , 5 industrial chemicals
• 2000 100 countries signed to phase out 12 of
  the most hazardous persistent organic pollutants
  (POPs), 9 of them hydrocarbons (DDT)
• United States has not signed this agreement

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Alternatives to Using Pesticides

• Fool the pest rotate crops, adjust plant times
• Provide homes for pest enemies
• Implant genetic resistance GMOs
• Bring in natural enemies natural predators
• Use insect perfumes
• Hormones
• Scald them

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Integrated Pest Management Is a Component of
Sustainable Agriculture

• Integrated pest management (IPM)
• Coordinate cultivation, biological controls, and
  chemical tools to reduce crop damage to an
  economically tolerable level
• Disadvantages
• expert knowledge

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Use Government Policies to Improve Food
Production and Security

• Control prices keep artificially low
• Provide subsidies price supports, tax breaks,
  subsidies for 31 of global farm income
• Developed 280 billion /year
• Substitute traditional subsidies with ones that
  promote sustainable farming practices
• Subsidies to fishing promotes destructive
  fishing practices
• Let the marketplace decide

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Use Government Policies to Improve Food
Production and Security

• United Nations Childrens Fund (UNICEF) suggests
  these measures. Can be done at an average annual
  cost of 5-10 / child
• Immunizing children against childhood diseases
• Encourage breast-feeding
• Prevent dehydration in infants and children
• Prevent blindness Vitamin A capsule (75c/child)
• Provide family planning services
• Increase education for women

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How Can We Produce Food More Sustainably?

• Sustainable food production will require reducing
  topsoil erosion, eliminating overgrazing and
  overfishing, irrigating more efficiently, using
  integrated pest management, promoting
  agrobiodiversity, and providing government
  subsidies for more sustainable farming, fishing,
  and aquaculture.

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How Can We Produce Food More Sustainably?

• Producing enough food to feed the rapidly
  growing human population will require growing
  crops in a mix of monocultures and poly cultures
  and decreasing the enormous environmental impacts
  of industrialized food production.

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Reduce Soil Erosion

• Soil conservation, some methods
• Terracing
• Contour planting
• Strip cropping with cover crop
• Alley cropping, agroforestry
• Windbreaks or shelterbeds
• Conservation-tillage farming
• No-till
• Minimum tillage
• Identify erosion hotspots

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Solutions Mixture of Monoculture Crops Planted
in Strips on a Farm
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Restore Soil Fertility

• Organic fertilizer
• Animal manure dung , urine
• Green manure freshly cut, growing green
  vegetation
• Compost microorganisms to break down organic
  waste
• Commercial inorganic fertilizer active
  ingredients
• Nitrogen
• Phosphorous
• Potassium
• Crop Rotation

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Reduce Soil Salinization and Desertification

• Soil salinization
• Prevention
• Clean-up
• Desertification, reduce
• Population growth
• Overgrazing
• Deforestation
• Destructive forms of planting, irrigation, and
  mining

Flush soil (expensive and wastes water
Reduce irrigation
Stop growing crops for 25 years
Switch to salt-tolerant crops (such as barley,
cotton, and sugar beet
Install underground drainage systems (expensive)
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Shift to More Sustainable Agriculture

• Paul Mader and David Dubois
• 22-year study
• Compared organic and conventional farming
• Benefits of organic farming
• little or no use of synthetic pesticides,
  fertilizers or genetically engineered seeds,
  fields free for 3 years
• livestock raised without genetic engineering

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SOLUTIONS
Organic Farming
Improves soil fertility
Reduces soil erosion
Retains more water in soil during drought years
Uses about 30 less energy per unit of yield
Lowers CO2 emissions
Reduces water pollution by recycling livestock
wastes
Eliminates pollution from pesticides
Increases biodiversity above and below ground
Benefits wildlife such as birds and bats
Fig. 12-32, p. 308
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Scientists Are Studying Benefits and Costs of
Organic Farming

• Effect of different fertilizers on nitrate
  leaching in apple trees
• calcium nitrate and alfalfa residues, composted
  chicken manure, integrated approach (combined)
• Less nitrate leached into the soil after organic
  fertilizers were used 4.4 to 5.6 times less

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Comparison of the Roots between an Annual Plant
and a Perennial Plant
Roots of a tall grass prairie plant
Annual Wheat Crop Plant
Better at using water and nutrients
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Buy Locally Grown Food

• Supports local economies
• Does not have to be transported far reduces
  greenhouse gas emissions, 5 to 17 times less
• Reduces environmental impact on food production
  grow organic food or buy organic food grown
  locally
• Community-supported agriculture (CSA)