Food, Soil, and Pest Management - PowerPoint PPT Presentation

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Food, Soil, and Pest Management

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Title: Food, Soil, and Pest Management


1
Food, Soil, and Pest Management
  • Chapter 12

2
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).

3
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

4
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

5
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

6
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

7
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
    14
  • 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

8
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

9
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

10
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

11
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12
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

13
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

14
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

15
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

16
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

17
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

18
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

19
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.

20
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.

21
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

22
Solutions Mixture of Monoculture Crops Planted
in Strips on a Farm
23
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

24
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)
25
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

26
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
27
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

28
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
29
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)
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