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. 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.

5. 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

6. 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

7. 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

8. 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.

9. Where We Get Food (1) Major sources: Croplands
Rangelands, pastures, and feedlots
Fisheries and aquaculture

10. 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

11. 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

12. 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

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

14. Traditional Agriculture
2.7 billion people in developing countries
Traditional subsistence agriculture
Traditional intensive agriculture
Monoculture
Polyculture

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

16. 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

17. 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

18. 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

19. 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

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

21. 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

22. 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

23. 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.

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

25. 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

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

27. 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

28. 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

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

30. 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

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

32. 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

33. 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).

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

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

36. 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

37. 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

38. 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

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

40. 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

41. 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

42. 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

43. 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.

44. 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

45. 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

46. 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.

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

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

49. 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

50. 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

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

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

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

54. 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

55. 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

56. 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.

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

58. 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.