1. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Agriculture and Food

2. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Outline Nutrition and Food Supplies Soil  Structure  Erosion Agricultural Resources  Water  Energy Genetic Engineering Sustainable Agriculture

3. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Subsistence agriculture Commercial agriculture

4. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.

5. NUTRITION AND FOOD SUPPLIES World food supplies have more than kept up with human population growth over the past two centuries.  1950 - 2.5 billion people - average daily diet was less than 2,000 calories/person.  2001- 6.0 billion people - world food supply can provide more than 2,500 calories/person.

6. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Nutrition The most common dietary problem in wealthy countries is over-nutrition.  In NA and Europe, average daily caloric intake is 3,500 calories. Sub-Saharan Africa has not kept food production up to pace of population growth. Collapse of Soviet Union also led to significant collapse in food production.

7. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.

8. Chronic Hunger and Food Security About 1 in 5 people in the developing world are considered chronically hungry.  200 million children - Can lead to permanently stunted growth, mental retardation, and other developmental disorders.  Poverty is the greatest threat to food security (The ability to obtain sufficient food on a daily basis).

9. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Chronic Hunger and Food Security

10. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Essential Nutrients Malnourishment - Nutritional imbalance caused by a lack of specific dietary components.  In poorer countries, people often cannot afford to purchase an adequate variety of foods, including meats and vegetables.

11. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Risk of Inadequate Nutrition

12. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Famines Famines are characterized by large-scale food shortages, massive starvation, social disruption, and economic chaos.  Mass migrations often occur because productive capacity has been sacrificed.  Environmental conditions are immediate trigger, but politics and economics are often underlying problems. - Arbitrary political boundaries block historic access to refuge areas.

13. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Famines Aid policies of rich countries often serve to distribute surplus commodities and produce feeling of generosity.  Food camps have serious drawbacks: - Stress and crowding - Lack of sanitation - Close contact to epidemic diseases

14. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. MAJOR FOOD SOURCES Three crops deliver majority of world’s nutrients:  Wheat, Rice and Corn - Potatoes, barley, oats and rye are staples in cool, moist climates. - Cassava, sweet potatoes, and other roots and tubers are staples in warm wet climates.

15. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Meat and Milk Meat and Milk distribution highly inequitable.  Core makes up 20% of world population, but consumes 80% of meat and milk.  60% of production occurs in lesser developed countries.  90% of grain grown in NA is used to feed livestock.

16. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Meat Every 16 kg of grain and soybeans fed to beef cattle in feedlots produce about 1 kg of edible beef.  If we ate the grain directly, we would obtain 21x more calories and 8x more protein than we get from eating the beef.

17. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Seafood Seafood is an important protein source. Since 1989, 13/17 major fisheries have declined or become commercially inviable. Between 1970-1990, number and average vessel size of world fishing fleet doubled.  Now have twice the capacity needed to extract total annual sustainable harvest. - Catching $70 billion cost $124 billion.  1/4 animals considered by-catch.

18. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. SOIL: A RENEWABLE RESOURCE Soil - A complex mixture of weathered minerals, partially decomposed organic materials, and a host of living organisms.  At least 20,000 different soil types in the US. - Vary due to influences of parent material, time, topography, climate, and organisms.  Can be replenished and renewed.

19. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.

21. Ways we use and abuse soils Approximately 11% of the earth’s land area is currently in agricultural production.  Up to four times as much could potentially be converted to agricultural use. - Much of this additional land suffers from constraints.

22. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Soil Degradation

23. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Land Resources In developed countries, 95% of recent agricultural growth has been from altered agricultural practices (pesticides - fertilizer).  Less land cultivated in NA now than 100 years ago. Many developing countries are reaching limit of lands that can be exploited for agriculture without unacceptable social and environmental costs.

24. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Land Degradation Estimated nearly 3 million ha of cropland ruined annually via erosion, 4 million ha transformed into deserts, and 8 million ha converted to non-agricultural uses.

25. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Land Degradation Definitions of degradation are based on both biological productivity and expectations of what land should be like.  Generally, land is considered degraded when soil is impoverished or eroded, run- off is contaminated, or biodiversity is diminished. - Water and wind are the driving forces for vast majority of soil degradation.

26. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Land Degradation

27. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Erosion Erosion is an important natural process, resulting in redistribution of the products of geologic weathering, and is part of both soil formation and soil loss.  Worldwide, erosion reduces crop production by equivalent of 1% of world cropland per year.

28. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Mechanisms of Erosion Rill Erosion - Small rivulets of running water gather together and cut small channels in the soil. Gully Erosion - Rills enlarge to form bigger channels too large to be removed by normal tillage. Streambank Erosion - Washing away of soil from established streambanks.

29. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Mechanisms of Erosion Wind can equal or exceed water as an erosive force, especially in a dry climate and on flat land.  Intensive farming practices: - Row crops leave soil exposed - Weed free-fields - Removal of windbreaks - No crop-rotation or resting periods - Continued monocultures

30. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. CHEMICAL INPUTS Fertilizers Pesticides Fungicides Herbicides (weed killers)

31. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Fertilizer Lack of nitrogen, potassium, and phosphorus often limits plant growth.  Adding nutrients via fertilizer usually stimulates growth and increases crop yields. - 1950 - 90 Average of 20 to 91 kg/ha fertilizer used.  Manure and nitrogen-fixing bacteria are alternative methods of replenishing soil nutrients.

32. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.

33. Pesticide Problems Non-Target Species  Up to 90% of pesticides never reach intended target. Pesticide Resistance  Resistant members of a population survive pesticide treatment and produce more resistant offspring. - Pest Resurgence

34. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Pesticide Resistance

35. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Environmental Persistence and Mobility Many persistent organic pollutants were banned globally in 2001.  Use was banned or restricted in developing countries for years, but between 1994 and 1996, the US shipped more than 100,000 tons of DDT and POP’s annually. - Many returned to US in agricultural products and migrating wildlife.

36. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. DDT pesticide effect on birds; U.S. recovery since ban Still exported to Periphery

37. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Human Health Problems WHO estimates between 3.5 and 5.0 million people suffer acute pesticide poisoning, and 20,000 die, each year.  At least two-thirds resulting from occupational hazards in developing countries.  Long-term health effects difficult to conclusively document. - PCB’s have been linked to learning deficiencies in children.  Intake during mother’s pregnancy.

38. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Alternatives to Pesticide Use  Crop Rotation  Mechanical Cultivation  Flooding Fields  Habitat Diversification  Growing in Pest-Free Zones  Adjusting Planting Times  Plant Mixed Polycultures

39. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. ENERGY Farming in industrialized countries is highly energy-intensive.  Between 1920-1980, energy use rose directly with mechanization of agriculture, and indirectly with spraying of chemicals.  Altogether, US food system consumes 16% of total energy use. - Most foods require more energy to produce, process, and transport than we yield from them.

40. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Energy

41. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. NEW CROPS AND GENETIC ENGINEERING Most of world food comes from 16 widely grown crops.  At least 3,000 species of plants have been used for food at some point in time. - Many new or unconventional varieties might be valuable food supplies.  Winged-bean  Triscale

42. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Green Revolution Most major improvements in farm production have come from technological advances and modification of a few well-known species.  Corn yields jumped from 25 bushels per acre to 130 per acre in last century. - Most of gain accomplished through conventional plant breeding.  Also seen rise of dwarf varieties. Green Revolution - Spread of new varieties around the world.

43. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Green Revolution

44. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. “Green Revolution” benefits Core exports high-yield “miracle” seeds Needed oil-based fertilizers, pesticides Asian rice crop up 66% in 1965-85 Favored areas with good soil, weather

45. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. “Green Revolution”

46. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. “Green Revolution” drawbacks Favored farmers who could afford seeds, inputs, machines, irrigation Indebted farmers lost land, moved to cities New “monocrops” lacked resistance to disease/pests Environmental contamination, erosion Oriented to export “cash crops,” not domestic food

47. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Genetic Engineering Genetically Modified Organisms (GMO’s)  Contain DNA possessing genes borrowed from unrelated species. - Can produce crops with pest-resistance and wider tolerance levels. - Opponents fear traits could spread to wild varieties, and increased expense would largely hurt smaller farmers.  70% of all processed foods in NA contain transgenic products.

48. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Genetic Engineering

49. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Genetic Engineering

50. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Biotechnology: Using organisms to… Make or modify products Improve plants or animals Develop new microorganisms Crossing different species  Genetic engineering

51. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Genetically Modified Organisms (GMO) Consumer concerns began in Europe, now in U.S. too

52. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Biotechnology benefits in agriculture Increase yields Increase pest resistance Grow crops in new areas

53. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Biotechnology drawbacks in agriculture High costs (available to few) Monocrops have less tolerance to disease Possible health effects, contamination of crops Corporate patents on life forms

54. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Bovine Growth Hormone (BGH)

55. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Starlink corn

56. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Monarch butterflies and corn pollen Possible effects of Bt-modified corn pollen

57. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Cloning First calf cloned in Wisconsin, 1997. Many clones die of complications. Ethical and economic conflicts

58. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.

59. SUSTAINABLE AGRICULTURE Soil Conservation  Managing Topography - Contour Plowing - Plowing across slope to slow flow of water. - Strip Farming - Planting different crops in alternating strips along land contours. - Terracing - Shaping land to create level shelves of earth to hold water and soil.

60. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Soil Conservation Providing Ground Cover  Annual row crops cause highest rates of erosion because they leave soil bare for much of the year. - Leave crop residue after harvest. - Plant cover crops after harvest.

61. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Soil Conservation Reduced Tillage  Minimum Till - Chisel plow  Conserv-Till - Coulter (Disc)  No-Till - Drilling Often farmers using conservation tillage must depend relatively heavily on pesticides.  Traditional tillage helped control weeds and pests.

62. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed. Summary Nutrition and Food Supplies Major Food Sources Soil  Structure  Erosion Agricultural Resources  Water  Energy Genetic Engineering Sustainable Agriculture

63. Cunningham - Cunningham - Saigo: Environmental Science 7 th Ed.