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ENVIRONMENTAL SCIENCE

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ENVIRONMENTAL SCIENCE 13e CHAPTER 10: Food, Soil, and Pest Management * Figure 10.1: Comparison of conventional industrialized agriculture and organic agriculture. – PowerPoint PPT presentation

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Title: ENVIRONMENTAL SCIENCE


1
ENVIRONMENTAL SCIENCE
13e
CHAPTER 10Food, Soil, and Pest Management
2
Core Case Study Is Organic Agriculture the
Answer? (1)
  • Organic agriculture as a component of sustainable
    agriculture
  • Certified organic farming
  • Less than 1 of world cropland
  • 0.1 of U.S. cropland
  • 6-18 in many European countries

3
Core Case Study Is Organic Agriculture the
Answer? (2)
  • Many environmental advantages over conventional
    farming
  • Requires more human labor
  • Organic food costs 10-75 more than
    conventionally grown food
  • Cheaper than conventionally grown food when
    environmental costs are included

4
Fig. 10-1, p. 206
5
Industrialized Agriculture
Uses synthetic inorganic fertilizers and sewage
sludge to supply plant nutrients Makes use of
synthetic chemical pesticides
Uses conventional and genetically modified
seeds Depends on nonrenewable fossil
fuels (mostly oil and natural gas)
Produces significant air and water pollution and
greenhouse gases Is globally export-oriented Use
s antibiotics and growth hormones to produce meat
and meat products
Fig. 10-1, p. 206
6
Organic Agriculture
Emphasizes prevention of soil erosion and the use
of organic fertilizers such as animal manure and
compost, but no sewage sludge to help replace
lost plant nutrients
Employs crop rotation and biological pest control
Uses no genetically modified seeds
Makes greater use of renewable energy such as
solar and wind power for generating electricity
Produces less air and water pollution and
greenhouse gases
Is regionally and locally oriented
Uses no antibiotics or growth hormones to produce
meat and meat products
Fig. 10-1, p. 206
7
10-1 What Is Food Security and Why Is It So
Difficult to Attain?
  • Concept 10-1A Many of the poor have health
    problems from not getting enough food, while many
    people in affluent countries suffer health
    problems from eating too much.
  • Concept 10-1B The greatest obstacles to
    providing enough food for everyone are poverty,
    political upheaval, corruption, war, and the
    harmful environmental effects of food production.

8
Poor Lack Sufficient Food
  • Enough food for all but in developing countries
    1/6 do not get enough to eat
  • Poverty Food insecurity
  • Chronic hunger
  • Poor nutrition
  • Food security

9
Nutrition
  • Macronutrients and micronutrients
  • Chronic undernutrition
  • Malnutrition
  • Low-protein, high-carbohydrate diet
  • Physical and mental health problems
  • 6 million children die each year
  • Vitamin and mineral deficiencies

10
Supplement 3, Fig. 11, p. S12
11
Fig. 10-2, p. 208
12
Fig. 10-3, p. 209
13
Overnutrition
  • Too many calories, too little exercise, or both
  • Similar overall health outlook as undernourished
  • 1.6 billion people eat too much
  • 66 of American adults overweight, 34 obese
  • Heart disease and stroke
  • Type II diabetes and some cancers

14
10-2 How Is Food Produced?
  • Concept 10-2 We have used high-input
    industrialized agriculture and lower-input
    traditional methods to greatly increase supplies
    of food.

15
Where We Get Food (1)
  • Major sources
  • Croplands
  • Rangelands, pastures, and feedlots
  • Fisheries and aquaculture

16
Where We Get Food (2)
  • Since 1960 tremendous increase in food supply
  • Better farm machinery
  • High-tech fishing fleets
  • Irrigation
  • Pesticides and fertilizers
  • High-yield varieties

17
Only a Few Species Feed the World
  • Food specialization in small number of crops
    makes us vulnerable
  • 14 plant species provide 90 of world food
    calories
  • 47 of world food calories comes from rice,
    wheat, and corn

18
Industrialized Agriculture (1)
  • High-input agriculture monocultures
  • Large amounts of
  • Heavy equipment
  • Financial capital
  • Fossil fuels
  • Water
  • Commercial inorganic fertilizers
  • Pesticides
  • Much food produced for global consumption

19
Industrialized Agriculture (2)
  • Plantation agriculture primarily in tropics
  • Bananas
  • Sugarcane
  • Coffee
  • Vegetables
  • Exported primarily to developed countries

20
Traditional Agriculture
  • 2.7 billion people in developing countries
  • Traditional subsistence agriculture
  • Traditional intensive agriculture
  • Monoculture
  • Polyculture

21
Science Focus Soil is the Base of Life on Land
(1)
  • Soil composed of
  • Eroded rock
  • Mineral nutrients
  • Decaying organic matter
  • Water
  • Air
  • Organisms

22
Science Focus Soil is the Base of Life on Land
(2)
  • Soil is a key component of earths natural
    capital
  • Soil profile
  • O Horizon
  • A horizon
  • B horizon
  • C horizon

23
Oak tree
Fern
Moss and lichen
Organic debris
Millipede
Honey fungus
Earthworm
Rock fragments
Grasses and small shrubs
Wood sorrel
O horizon Leaf litter
A horizon Topsoil
Mole
Bacteria
B horizon Subsoil
Fungus
C horizon Parent material
Bedrock
Mite
Immature soil
Young soil
Mature soil
Nematode
Root system
Red earth mite
Beetle larva
Fig. 10-A, p. 211
24
Green Revolution
  • Three-step green revolution
  • Selectively bred monocultures
  • High yields through high inputs fertilizer,
    pesticides, and water
  • Multiple cropping
  • Second green revolution fast-growing dwarf
    varieties of wheat and rice
  • 1950-1996 world grain production tripled

25
Fig. 10-4, p. 212
26
Case Study Industrialized Food Production in the
U.S.
  • Industrialized farming agribusiness
  • Increasing number of giant multinational
    corporations
  • 10 U.S. income spent on food
  • Subsidized through taxes

27
Case Study Brazil The Worlds Emerging Food
Superpower
  • Ample sun, water, and arable land
  • EMBRAPA government agricultural research
    corporation
  • 2-3 crops per year in tropical savanna
  • Lack of transportation impeding further growth as
    food exporter

28
Production of New Crop Varieties
  • Traditional
  • Crossbreeding
  • Artificial selection
  • Slow process
  • Genetic engineering
  • Genetic engineering
  • gt75 of U.S. supermarket food genetically
    engineered

29
Fig. 10-5, p. 214
30
Fig. 10-5, p. 214
31
Fig. 10-5, p. 214
32
Phase 1 Gene Transfer Preparations
A. tumefaciens
Plant cell
Extract plasmid
Extract DNA
plasmid
Foreign gene if interest
Foreign gene integrated into plasmid DNA.
Agrobacterium takes up plasmid
Phase 2 Make Transgenic Cell
A. tumefaciens (agrobacterium)
Enzymes integrate plasmid into host cell DNA.
Host cell
Fig. 10-5, p. 214
33
Foreign DNA
Host DNA
Transgenic plant cell
Nucleus
Phase 3 Grow Genetically Engineered Plant
Cell division of transgenic cells
Cultured cells divide and grow into
plantlets (otherwise teleological)
Transgenic plants with desired trait
Fig. 10-5, p. 214
34
Meat Production
  • Meat and dairy products are good sources of
    protein
  • Past 60 years meat production up five-fold
  • Half of meat from grazing livestock, other half
    from feedlots

35
Fish and Shellfish Production Have Increased
Dramatically
  • Aquaculture 46 of fish/shellfish production in
    2006
  • Ponds
  • Underwater cages
  • China produces 70 of worlds farmed fish

36
Fig. 10-6, p. 214
37
10-3 What Environmental Problems Arise from Food
Production?
  • Concept 10-3 Future food production may be
    limited by soil erosion and degradation,
    desertification, water and air pollution, climate
    change from greenhouse gas emissions, and loss of
    biodiversity.

38
Natural Capital Degradation
Food Production
Human Health
Biodiversity Loss
Water
Soil
Air Pollution
Loss and degradation of grasslands, forests, and
wetlands
Erosion
Water waste
Greenhouse gas emissions (CO2) from fossil fuel
use
Nitrates in drinking water (blue baby)
Loss of fertility
Aquifer depletion
Pesticide residues in drinking water, food, and
air
Increased runoff, sediment pollution, and
flooding from cleared land
Greenhouse gas emissions (N2O) from use of
inorganic fertilizers
Fish kills from pesticide runoff
Salinization
Waterlogging
Killing wild predators to protect livestock
Contamination of drinking and swimming water from
livestock wastes
Desertification
Pollution from pesticides and fertilizers
Greenhouse gas emissions of methane (CH4) by
cattle (mostly belching)
Loss of genetic diversity of wild crop strains
replaced by monoculture strains
Algal blooms and fish kills in lakes and
rivers caused by runoff of fertilizers
and agricultural wastes
Bacterial contamination of meat
Other air pollutants from fossil fuel use and
pesticide sprays
Fig. 10-7, p. 215
39
Soil Erosion
  • Flowing water
  • Wind
  • Soil fertility declines
  • Water pollution occurs
  • Some natural
  • Much due to human activity

40
Fig. 10-8, p. 216
41
Serious concern
Some concern
Stable or nonvegetative
Stepped Art
Fig. 10-9, p. 216
42
Drought and Human Activities
  • Desertification
  • Combination of prolonged draught and human
    activities
  • 70 of worlds drylands used for agriculture
  • Will be exacerbated by climate change

43
Fig. 10-10, p. 217
44
Effects of Irrigation
  • Leaves behind salts in topsoil
  • Salinization
  • Affects 10 of global croplands
  • Waterlogging
  • Attempts to leach salts deeper but raises water
    table
  • Affects 10 of global croplands

45
Fig. 10-11, p. 217
46
Limits to Expanding Green Revolutions
  • High-inputs too expensive for subsistence farmers
  • Water not available for increasing population
  • Irrigated land per capita dropping
  • Significant expansion of cropland unlikely for
    economic and ecological reasons

47
Industrialized Food Production Requires Huge
Energy Inputs
  • Mostly nonrenewable oil
  • Run machinery
  • Irrigation
  • Produce pesticides
  • Process foods
  • Transport foods
  • In U.S., food travels an average of 1,300 miles
    from farm to plate

48
Controversies over Genetically Engineered Foods
  • Potential long-term effects on humans
  • Ecological effects
  • Genes cross with wild plants
  • Patents on GMF varieties

49
Trade-Offs
Genetically Modified Crops and Foods
Projected Disadvantages
Projected Advantages
Irreversible and unpredictable genetic
and ecological effects
Need less fertilizer
Need less water
Harmful toxins in food from possible plant cell
mutations
More resistant to insects, disease, frost, and
drought
New allergens in food
Grow faster
Can grow in slightly salty soils
Lower nutrition
Increase in pesticide-resistant
insects, herbicide-resistant weeds, and plant
diseases
May need less pesticides
Tolerate higher levels of herbicides
Can harm beneficial insects
Higher yields
Less spoilage
Lower genetic diversity
Fig. 10-12, p. 219
50
Food and Biofuel Production Lead to Major Losses
of Biodiversity
  • Forests cleared
  • Grasslands plowed
  • Loss of agrobiodiversity
  • Since 1900, lost 75 of genetic diversity of
    crops
  • Losing the genetic library of food diversity

51
Industrial Meat Production Consequences
  • Uses large amounts of fossil fuels
  • Wastes can pollute water
  • Overgrazing
  • Soil compaction
  • Methane release greenhouse gas

52
Aquaculture Problems
  • Fish meal and fish oil as feed
  • Depletes wild fish populations
  • Inefficient
  • Can concentrate toxins such as PCBs
  • Produce large amounts of waste

53
Trade-Offs
Aquaculture
Advantages
Disadvantages
High efficiency
Needs large inputs of land, feed, and water
High yield in small volume of water
Large waste output
Can destroy mangrove forests and estuaries
Can reduce overharvesting of fisheries
Uses grain, fish meal, and fish oil to feed some
species
Low fuel use
Dense populations vulnerable to disease
High profits
Fig. 10-13, p. 220
54
10-4 How Can We Protect Cropsfrom Pests More
Sustainably?
  • Concept 10-4 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).

55
Natures Pest Control
  • Polycultures pests controlled by natural
    enemies
  • Monocultures and land clearing
  • Loss of natural enemies
  • Require pesticides

56
Fig. 10-14, p. 221
57
Increasing Pesticide Use
  • Up 50-fold since 1950
  • Broad-spectrum agents
  • Selective agents
  • Persistence
  • Biomagnification some pesticides magnified in
    food chains and webs

58
Trade-Offs
Conventional Chemical Pesticides
Advantages
Disadvantages
Save lives
Promote genetic resistance
Increase food supplies
Kill natural pest enemies
Pollute the environment
Profitable
Work fast
Can harm wildlife and people
Safe if used properly
Are expensive for farmers
Fig. 10-15, p. 222
59
Advantages of Modern Pesticides
  • Save human lives
  • Increase food supplies
  • Increase profits for farmers
  • Work fast
  • Low health risks when used properly
  • Newer pesticides safer and more effective

60
Disadvantages of Modern Pesticides
  • Pests become genetically resistant
  • Some insecticides kill natural enemies
  • May pollute environment
  • Harmful to wildlife
  • Threaten human health
  • Use has not reduced U.S. crop losses

61
Laws Regulate Pesticides
  • Environmental Protection Agency (EPA)
  • United States Department of Agriculture (USDA)
  • Food and Drug Administration (FDA)
  • Congressional legislation
  • Laws and agency actions criticized

62
Fig. 10-16, p. 224
63
Individuals Matter Rachel Carson
  • Biologist
  • DDT effects on birds
  • 1962 Silent Spring makes connection between
    pesticides and threats to species and ecosystems

64
Fig. 10-B, p. 223
65
Science Focus Ecological Surprises
  • Dieldrin killed malaria mosquitoes, but also
    other insects
  • Poison moved up food chain
  • Lizards and then cats died
  • Rats flourished
  • Operation Cat Drop
  • Villagers roofs collapsed from caterpillars
    natural insect predators eliminated

66
Alternatives to Pesticides
  • Fool the pest
  • Provide homes for pest enemies
  • Implant genetic resistance
  • Natural enemies
  • Pheromones to trap pests or attract predators
  • Hormones to disrupt life cycle

67
Fig. 10-18, p. 226
68
Integrated Pest Management
  • Evaluate a crop and its pests as part of
    ecological system
  • Design a program with
  • Cultivation techniques
  • Biological controls
  • Chemical tools and techniques
  • Can reduce costs and pesticide use without
    lowering crop yields

69
10-5 How Can We Improve Food Security?
  • Concept 10-5 We can improve food security by
    creating programs to reduce poverty and chronic
    malnutrition, relying more on locally grown food,
    and cutting waste.

70
Use Government Policies to Improve Food
Production and Security
  • Control food prices
  • Helps consumers
  • Hurts farmers
  • Provide subsidies to farmers
  • Price supports, tax breaks to encourage food
    production
  • Can harm farmers in other countries who dont get
    subsidies
  • Some analysts call for ending all subsidies

71
Reducing Childhood Deaths
  • 510 annual per child would prevent half of
    nutrition-related deaths
  • Strategies
  • Immunization
  • Breast-feeding
  • Prevent dehydration from diarrhea
  • Vitamin A
  • Family planning
  • Health education for women

72
10-6 How Can We Produce Food More Sustainably?
  • Concept 10-6 More sustainable food production
    involves reducing overgrazing and overfishing,
    irrigating more efficiently, using integrated
    pest management, promoting agrobiodiversity, and
    providing government subsidies only for more
    sustainable agriculture, fishing, and
    aquaculture.

73
Reduce Soil Erosion (1)
  • Terracing
  • Contour plowing
  • Strip cropping
  • Alley cropping
  • Windbreaks

74
Reduce Soil Erosion (2)
  • Shelterbelts
  • Conservation-tillage farming
  • No-till farming
  • Minimum-tillage farming
  • Retire erosion hotspots

75
Stepped Art
Fig. 10-19, p. 229
76
Fig. 10-19, p. 229
77
Fig. 10-19, p. 229
78
Fig. 10-19, p. 229
79
Fig. 10-19, p. 229
80
Government Intervention
  • Governments influence food production
  • Control prices
  • Provide subsidies
  • Let the marketplace decide
  • Reduce hunger, malnutrition, and environmental
    degradation
  • Slow population growth
  • Sharply reduce poverty
  • Develop sustainable low-input agriculture

81
Case Study Soil Erosion in the United States
  • Dust Bowl in the 1930s
  • 1935 Soil Erosion Act
  • Natural Resources Conservation Service
  • Helps farmers and ranchers conserve soil
  • One-third topsoil gone
  • Much of the rest degraded
  • Farmers paid to leave farmland fallow

82
Restoring Soil Fertility
  • Organic fertilizers
  • Animal manure
  • Green manure
  • Compost
  • Crop rotation uses legumes to restore nutrients
  • Inorganic fertilizers pollution problems

83
Solutions
Soil Salinization
Prevention
Cleanup
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)
Fig. 10-20, p. 230
84
Fig. 10-21, p. 231
85
Sustainable Meat Production
  • Shift to eating herbivorous fish or poultry
  • Eat less meat
  • Vegetarian

86
7
Beef cattle
Pigs
4
2.2
Chicken
Fish (catfish or carp)
2
Fig. 10-22, p. 231
87
Solutions
Sustainable Organic Agriculture
More
Less
High-yield polyculture
Soil erosion
Aquifer depletion
Organic fertilizers
Overgrazing
Biological pest control
Overfishing
Integrated pest management
Loss of biodiversity
Efficient irrigation
Food waste
Perennial crops
Subsidies for unsustainable farming and fishing
Crop rotation
Water-efficient crops
Soil salinization
Soil conservation
Population growth
Subsidies for sustainable farming and fishing
Poverty
Fig. 10-23, p. 232
88
Shift to More Sustainable Agriculture
  • Organic farming
  • Perennial crops
  • Polyculture
  • Renewable energy, not fossil fuels

89
Six Strategies for Sustainable Agriculture
  • Increase research on sustainable agriculture
  • Set up demonstration projects
  • International fund to help poor farmers
  • Establish training programs
  • Subsidies only for sustainable agriculture
  • Education program for consumers

90
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. 10-24, p. 233
91
Fig. 10-25, p. 234
92
Science Focus The Land Institute and Perennial
Culture
  • Polycultures of perennial crops
  • Live for years without replanting
  • Better adapted to soil and climate conditions
  • Less soil erosion and water pollution
  • Increases sustainability

93
Fig. 10-B, p. 233
94
Three Big Ideas from This Chapter - 1
  • About 925 million people have health problems
    because they do not get enough to eat and 1.6
    billion people face health problems from eating
    too much.

95
Three Big Ideas from This Chapter - 2
  • Modern industrialized agriculture ha a greater
    harmful impact on the environment than any other
    human activity.

96
Three Big Ideas from This Chapter - 3
  • More sustainable forms of food production will
    greatly reduce the harmful environmental impacts
    of current systems while increasing food security
    and national security for all countries.
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