1. ENVIRONMENTAL SCIENCE
CHAPTER 10: Food, 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)
Figure 10.1: Comparison of conventional industrialized agriculture and organic agriculture. In the United States, a label of
100 percent organic means that a product is raised only by organic methods and contains all organic ingredients. Products
labeled organic must contain at least 95% organic ingredients. And products labeled made with organic ingredients must
contain at least 70% organic ingredients but cannot display the USDA Organic seal on their packages.
Produces significant air and water
pollution and greenhouse gases
Is globally export-oriented
Uses 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
Figure 10.1: Comparison of conventional industrialized agriculture and organic agriculture. In the United States, a label of
100 percent organic means that a product is raised only by organic methods and contains all organic ingredients. Products
labeled organic must contain at least 95% organic ingredients. And products labeled made with organic ingredients must
contain at least 70% organic ingredients but cannot display the USDA Organic seal on their packages.
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 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 earth’s natural capital
Soil profile
O Horizon
A horizon
B horizon
C horizon

23. Fig. 10-A, p. 211

24. How might the picture change if the tree were removed?
Oak
tree
Fern
Moss and
lichen
Organic
debris
Millipede
Honey
fungus
Rock
fragments
Grasses and
small shrubs
Earthworm
Wood
sorrel
O horizon
Leaf litter
A horizon
Topsoil
Mole
Bacteria
B horizon
Subsoil
Fungus
Active Figure 10.A: Soil formation and generalized soil profile. Horizons, or layers, vary in number, composition, and thickness, depending
on the type of soil. See an animation based on this figure at CengageNOW. Questions: What role do you think the tree in this figure plays in soil formation?
How might the picture change if the tree were removed?
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

25. 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
– world grain production tripled

26. Fig. 10-4, p. 212

27. 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

28. Case Study: Brazil – The World’s 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

29. Production of New Crop Varieties
Traditional
Crossbreeding
Artificial selection
Slow process
Genetic engineering
>75% of U.S. supermarket food genetically engineered

30. Fig. 10-5, p. 214

31. Fig. 10-5, p. 214

32. Fig. 10-5, p. 214

33. 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
Figure 10.5: Genetic engineering: steps in genetically modifying a plant. Question: How does this process change the nature of evolution
by natural selection?
A. tumefaciens
(agrobacterium)
Enzymes integrate plasmid
into host cell DNA.
Host cell
Fig. 10-5, p. 214

34. Foreign DNA
Host DNA
Nucleus
Transgenic
plant cell
Phase 3
Grow Genetically
Engineered Plant
Cell division of
transgenic cells
Cultured cells
divide and grow
into plantlets
(otherwise
teleological)
Figure 10.5: Genetic engineering: steps in genetically modifying a plant. Question: How does this process change the nature of evolution
by natural selection?
Transgenic plants
with desired trait
Fig. 10-5, p. 214

35. 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

36. Fish and Shellfish Production Have Increased Dramatically
Aquaculture – 46% of fish/shellfish production in 2006
Ponds
Underwater cages
China produces 70% of world’s farmed fish

37. Fig. 10-6, p. 214

38. 10-3 What Environmental Problems Arise from Food Production?
Concept 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.

39. Fig. 10-7, p. 215

40. Natural Capital Degradation
Food Production
Biodiversity Loss
Soil
Water
Air Pollution
Human Health
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
Fish kills from
pesticide runoff
Salinization
Increased runoff,
sediment pollution,
and flooding from
cleared land
Greenhouse gas
emissions (N2O) from
use of inorganic
fertilizers
Waterlogging
Killing wild predators
to protect livestock
Figure 10.7: Natural capital degradation: major harmful environmental effects of food production (Concept 10-3).
According to a 2008 study by the U.N. Food and Agriculture Organization (FAO), more than 20% of the world’s cropland
(65% in Africa) has been degraded to some degree by soil erosion, salt buildup, and chemical pollution. This
threatens the food supply for about a quarter of the world’s population who are trying to eke out a living on such
degraded land. Question: Which item in each of these categories do you believe is the most harmful?
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

41. Soil Erosion Flowing water Wind Soil fertility declines
Water pollution occurs
Some natural
Much due to human activity

42. Fig. 10-8, p. 216

43. Fig. 10-9, p. 216

44. Figure 10. 9: Natural capital degradation: global soil erosion
Figure 10.9: Natural capital degradation: global soil erosion. Question: Can you see any geographical pattern associated
with this problem? (Data from U.N. Environment Programme and the World Resources Institute).
Serious concern
Some concern
Stable or nonvegetative
Stepped Art
Fig. 10-9, p. 216

45. Drought and Human Activities
Desertification
Combination of prolonged draught and human activities
70% of world’s drylands used for agriculture
Will be exacerbated by climate change

46. Fig , p. 217

47. Effects of Irrigation Leaves behind salts in topsoil Salinization
Affects 10% of global croplands
Waterlogging
Attempts to leach salts deeper but raises water table

48. Fig , p. 217

49. 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

50. 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

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

52. Fig , p. 219

53. Trade-Offs Genetically Modified Crops and Foods Projected Advantages
Disadvantages
Need less fertilizer
Irreversible and
unpredictable genetic and
ecological effects
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
Figure 1012: Projected advantages and disadvantages of genetically modified crops and foods.
Questions: Which two advantages and which two disadvantages do you think are the most important?
Why?
May need less pesticides
Increase in
pesticide-resistant insects,
herbicide-resistant weeds,
and plant diseases
Tolerate higher levels of
herbicides
Can harm beneficial insects
Higher yields
Less spoilage
Lower genetic diversity
Fig , p. 219

54. 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

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

56. 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

57. Fig , p. 220

58. 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
Figure 10.13: Advantages and disadvantages of aquaculture. Questions: Which single advantage
and which single disadvantage do you think are the most important? Why?
Uses grain, fish meal, and fish oil to feed some species
Low fuel use
Dense populations
vulnerable to disease
High profits
Fig , p. 220

59. 10-4 How Can We Protect Crops from Pests More Sustainably?
Concept 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).

60. Nature’s Pest Control
Polycultures – pests controlled by natural enemies
Monocultures and land clearing
Loss of natural enemies
Require pesticides

61. Fig , p. 221

62. Increasing Pesticide Use
Up 50-fold since 1950
Broad-spectrum agents
Selective agents
Persistence
Biomagnification – some pesticides magnified in food chains and webs

63. Fig , p. 222

64. Trade-Offs Conventional Chemical Pesticides Advantages Disadvantages
Save lives
Promote genetic
resistance
Increase food
supplies
Kill natural pest enemies
Profitable
Figure 10.15: Advantages and disadvantages of conventional chemical pesticides. Questions: Which
single advantage and which single disadvantage do you think are the most important? Why?
Pollute the environment
Work fast
Can harm wildlife and
people
Safe if used
properly
Are expensive for farmers
Fig , p. 222

65. 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

66. 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

67. 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

68. Fig , p. 224

69. Individuals Matter: Rachel Carson
Biologist
DDT effects on birds
1962: Silent Spring makes connection between pesticides and threats to species and ecosystems

70. Fig. 10-B, p. 223

71. 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

72. 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

73. Fig , p. 226

74. 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

75. 10-5 How Can We Improve Food Security?
Concept We can improve food security by creating programs to reduce poverty and chronic malnutrition, relying more on locally grown food, and cutting waste.

76. 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 don’t get subsidies
Some analysts call for ending all subsidies

77. Reducing Childhood Deaths
$5–$10 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

78. 10-6 How Can We Produce Food More Sustainably?
Concept 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.

79. Reduce Soil Erosion (1) Terracing Contour plowing Strip cropping
Alley cropping
Windbreaks

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

81. Fig , p. 229

82. Fig , p. 229

83. Fig , p. 229

84. Fig , p. 229

85. (a) Terracing
(b) Contour planting and strip cropping
(c) Alley cropping
(d) Windbreaks
Figure 10.19: Soil conservation methods include (a) terracing, (b) contour planting and strip cropping, (c) alley
cropping, and (d) windbreaks (Concept 10-6). The problem is that modern industrialized farming operations make
little use of these well-known and effective ways to conserve fertile topsoil.
Stepped Art
Fig , p. 229

86. 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

87. 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

88. Restoring Soil Fertility
Organic fertilizers
Animal manure
Green manure
Compost
Crop rotation uses legumes to restore nutrients
Inorganic fertilizers – pollution problems

89. Fig , p. 230

90. Solutions Soil Salinization Prevention Cleanup
Flush soil (expensive and wastes water)
Reduce irrigation
Stop growing crops for
2–5 years
Figure 10.20: Methods for preventing and cleaning up soil salinization (Concept 10-6). Questions: Which two of these solutions do you
think are the most important? Why?
Switch to salt-tolerant crops (such as barley, cotton, and sugar beet)
Install underground
drainage systems
(expensive)
Fig , p. 230

91. Fig , p. 231

92. Sustainable Meat Production
Shift to eating herbivorous fish or poultry
Eat less meat
Vegetarian

93. Fig , p. 231

94. Beef cattle 7 Pigs 4 Chicken 2.2 Fish (catfish or carp) 2
Figure 10.22: Efficiency of converting grain into animal protein. (Data in kilograms of grain per kilogram of body weight added.)
Question: If you eat meat, what changes could you make in your meat-eating habits to reduce your environmental impact? (Data
from U.S. Department of Agriculture)
Fish (catfish
or carp) 2
Fig , p. 231

95. Fig , p. 232

96. 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
Figure 10.23: Major components of more sustainable, low-throughput agriculture based mostly on mimicking and working with nature
(Concept 10-6). Questions: Which two solutions do you think are the most important? Why?
Subsidies for
unsustainable
farming and
fishing
Crop rotation
Water-efficient
crops
Soil salinization
Soil conservation
Subsidies for
sustainable farming
and fishing
Population growth
Poverty
Fig , p. 232

97. Shift to More Sustainable Agriculture
Organic farming
Perennial crops
Polyculture
Renewable energy, not fossil fuels

98. 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

99. Fig , p. 233

100. 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
Figure 10.24: Environmental benefits of organic farming over conventional farming, based on 22 years of research comparing
these two systems at the Rodale Institute in Kutztown, Pennsylvania (USA). (Data from Paul Mader, David Dubois, and David Pimentel)
Eliminates pollution from
pesticides
Increases biodiversity above and
below ground
Benefits wildlife such as birds
and bats
Fig , p. 233

101. Fig , p. 234

102. 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

103. Fig. 10-B, p. 233

104. 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.

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

106. 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.

107. Animation: Land Use
PLAY
ANIMATION

108. Animation: Soil Profile
PLAY
ANIMATION

109. Animation: Resources Depletion and Degradation
PLAY
ANIMATION

110. Animation: Acid Deposition
PLAY
ANIMATION

111. Animation: Transferring Genes into Plants
PLAY
ANIMATION

112. Animation: Effects of Deforestation
PLAY
ANIMATION

113. Animation: Ocean Provinces
PLAY
ANIMATION

114. Animation: Pesticide Examples
PLAY
ANIMATION

115. Video: The Problem with Pork
PLAY
VIDEO

116. Video: Food Allergy Increase
PLAY
VIDEO

117. Video: Fat Man Walking
PLAY
VIDEO

118. Video: Desertification in China
PLAY
VIDEO