1. Food and Agriculture Chapter15

2. Feeding the World
Do you think there is enough food available in the world to feed everyone? In your opinion, how many people in the world do not get enough to eat each day?

3. Feeding the World
Famine- widespread starvation caused by a shortage of food.
In 1985, lack of rain, loss of soil, and war caused crops to fail in Ethiopia.

4. Humans and Nutrition
Food is a source of energy and contains materials for maintaining body tissues.
Calories- the amount of energy in food.

5. Humans and Nutrition
Malnutrition occurs when people do not consume enough calories or not a sufficient variety of foods.
Many forms of malnutrition.
Example: Protein-energy malnutrition.

6. Sources of Nutrition
The food produced in the greatest amounts world wide is grains.
In most parts of the world, people eat foods high in carbohydrates.
Grains are high in carbohydrates.

7. Diets Around the World
People in developed countries tend to eat more food and larger portions of proteins and fats than people eat in developing countries.

8. The Ecology of Food
Feeding everyone while maintaining natural ecosystems is difficult to accomplish.
Different types of agriculture have different environmental impacts and levels of efficiency.

9. Food Efficiency
Efficiency is measured by the amount of food produced with the least amount of resources used.
It takes more energy, water and land to produce a calorie of food from an animal then it does to produce a calorie from a plant.

10. Food Efficiency
Since it is less expensive to grow grain than raise animals, most of the diets around the world are based largely on plants.
Meat from animals, however, provide us with more nutrients per gram than plants do.

11. World Food Problems
Farmers produces enough grain food for 10 billion people. (vegetarian diet).
However, many of us consume 1/3rd of our calories from animals instead of grain.

12. Subsistence farmers
Subsistence farmers work tiny plots of land to produce enough food for their family and sell what is left to local people.
Lack access to water for irrigation, which would increase their yield.

13. Poverty Malnutrition is the result of poverty.
Poverty is defined as an income of less than a dollar a day.
The worlds hungry mainly live in Asia, Africa, and parts of South America.

14. Poverty
The number of people in poverty has declined by nearly a ½ billion since 1980.
Reason- Asia, especially in China and India due to urbanization.

15. The Green Revolution
A period of time when wheat production doubled in production.
Resulted from new varieties of grain
These new grains produced large yields
Reduced the price of food and improved nutrition

16. The Green Revolution Drawbacks:
Subsistence farmers cannot afford the new crops.
It requires more water and fertilizers.
Loss of biodiversity
More pesticide use

17. Arable Land Land that can be used to grow crops
Urban areas occupy 3% of the Earth’s land surface, often expanding into arable land.
Only ~10% of the Earth’s surface

18. Traditional Farming: 4 basic processes
Plowing
Fertilization
Irrigation
Pest Control

19. Plowing Plowing helps grow crops by Mixing soil nutrients
Loosening soil particles
Uprooting weeds

20. Traditional Plowing

21. Fertilizers
Fertilizers, such as manure, are used to enrich the soil so that plants grow strong and healthy.
Organic Manure Tumbling Machine
Manure Runoff

22. Irrigation
Traditionally, fields were irrigated by water flowing through ditches.

23. Modern Farming
In industrialized countries, farming processes are now carried out using modern agricultural machines.
Machinery powered by fossil fuels is now used to plow the soil and harvest crops.

24. Modern Fertilizer
Synthetic chemical fertilizers are now used instead of manure and plant wastes to fertilize soil.

25. Fertile Soil: The Living Earth
Fertile Soil- soil that can support the growth of healthy plants

26. Topsoil The surface layer of soil Characteristics:
Usually richer in organic matter
The layer in which plant roots grow
Is composed of
Living organisms
Rock particles
Water
Air
Organic matter: decomposing organisms

27. Topsoil

28. Chemical Weathering
Soil forms when rock is broken down into small fragments by wind, water, and chemical weathering.
Chemical weathering happens when the minerals in the rock react chemically with substances, such as water, to form new materials.

29. Erosion The movement of rock and soil by wind and water
Without topsoil, crops cannot be grown.
Topsoil pours into the ocean at the mouth of the Mississippi River, here seen from space.
Topsoil eroding from North American farmland.

30. Erosion Farming methods increase the rate of soil erosion:
Plowing loosens the soil and removes plants that hold the soil in place
Water runoff from irrigation systems carries soil with it

31. Erosion happens easily where the soil surface is bare.
Water runs off instead of soaking into soils, causing flooding and erosion downstream.
Erosion can remove huge amounts of soil.

32. Land Degradation
Occurs when human activity or natural processes damage the land so that it can no longer support the local ecosystem

33. Desertification
The process by which land in arid or semiarid areas becomes more desert-like.

34. Desertification
Too many crops are planted too frequently, combined with overgrazing, the land has fewer plants to hold the topsoil in place.
Therefore, large arid areas have become desert and can no longer produce food.

35. Soil Conservation Building soil-retaining terraces Contour plowing
Leaving strips of vegetation
No-till farming

36. Enriching the Soil
Traditional farming methods used organic matter to enrich the soil.
The organic matter decomposes and adds nutrients to the soil and improves the texture.

37. Enriching the Soil
Today, inorganic fertilizers are used to enrich soil.
Inorganic fertilizers contain
Nitrogen
Phosphorus
Potassium
Without these fertilizers, world food production would less than half of what it is today.

38. Enriching the Soil
Compost is partly decomposed organic matter

39. Salinization The accumulation of salts in the soil
Usually occurs in areas with low rainfall
Irrigation water comes from rivers and groundwater, which is saltier than rainwater.
When water evaporates from irrigated land, salts are left behind.
Eventually, the soil may become so salty that plants cannot survive.

40. Salinization
Irrigation can also cause salinization by raising groundwater levels temporarily.
Salinization can be slowed if irrigation canals are lined to prevent water from seeping into the soil.

41. Pest Control
Pests destroy about 33% of the world’s potential food harvest.
Crops in tropical areas suffer greater insect damage because insects grown and reproduce faster.

42. Pest
Any organism that occurs where it is not wanted or that occurs in large enough numbers to cause economic damage.

43. Crop plants vs. Wild plants
More protection
Grown throughout landscape
Pest predators live on/near plant
Evolved defenses
Crops Plants
Grown together in a large field = easy access to one-stop food source

44. Crop plants vs. Wild plants

45. Pesticides Chemicals used to kill insects, weeds, and other crop pests
Can harm beneficial plants, insects, wildlife, and humans

46. Pesticides Spraying large amounts  resistance
Resistance is the ability to survive exposure to a particular pesticide (pest is not killed)

47. Pesticides Human Health Concerns: Increase cancer rate among children
Can cause nervous system disorders
Pesticide workers become ill
People who live nearby may be endangered by accidental chemical leaks

48. Pesticides: Human Health Concerns
child of farm workers, born with birth defects attributable to pesticides (PBP)
Burn from pesticide exposure

49. Persistent Pesticides
Do not break down rapidly into harmless chemicals in nature
They end up accumulating in the water and soil.

50. Persistent Pesticides
DDT (dichlorodiphenyltrichloroethane) was banned in the United States in the 1970s as a persistent pesticide.
It can still be detected in the environment and has been found in women’s breast milk.

51. Biological Pest Control
The use of living organisms to control pests
Use of natural/wild enemies to control pests

52. Pathogens Organisms that cause disease
Bacillus thuringiensis (Bt): a bacteria that is the most common pathogen used to control pests

53. Plant Defenses
Scientists and farmers have bred plant varieties that have defenses against pests.
If you buy a plant or seed with ‘VNT’ on the label means it is resistant to certain fungi, worms, and viruses.

54. Disrupting Insect Breeding
Growth Regulator- a chemical that interferes with some stage of a pest’s life cycle
Example: flea pills for dogs
Flea sucks the dog’s blood and ingests growth regulator
Growth regulator stops the flea’s eggs from developing into adult fleas

55. Disrupting Insect Breeding
Pheromones- chemicals produced by one organism that affect the behavior of another organism; male & female attraction
Treating crops with
pheromones can confuse
the pests and interfere
with mating

56. Integrated Pest Management
The modern method of controlling pests on crops
The goal is to reduce economic damage to crops.

57. Integrated Pest Management
Biological methods are the first methods used to control a pest.
So, natural predators, pathogens, and parasites of the pest may be introduced.

58. Genetic Engineering
The genetic material in a living cell is modified for medical or industrial use.
This involves isolating genes from one organism and implanting them into another.

59. Genetic Engineering
The plants that result from genetic engineering are called genetically modified (GM) plants.

60. Sustainable Agriculture
Farming that conserves natural resources and helps keep the land productive indefinitely
Also called low-input farming

61. Sustainable Agriculture
Characteristics
Minimizes the use of energy and water
Reduces the use of fertilizer and pesticides
Involves planting productive, pest-resistant crops
Plants crops that require little energy and water

62. Domesticated Animals
To include: Sheep, horses, dogs, chickens, pigs, goats, fish, cattle, bees, and shellfish.

63. •Fish are an important food source to human.
Food From Water
•Fish are an important food source to human.
•Harvesting fish is an important industry worldwide.
•Environmental pressure: Overharvesting.
•Overharvesting occurs when humans catch and remove more organisms within a population faster than the population can replenish.

64. Aquaculture
To deter overharvesting, we began to raise aquatic organism for human consumption, aka. Aquaculture.

65. Aquaculture There are a number of aqua cultural methods used today.
Oyster farms

66. Aquaculture
The most common is fish farms. They generally consist of many individual ponds that contain fish at specific stages of development.

67. Aquaculture
The ranch method is also used, fish such as salmon are raised until they reach a certain age then released.

68. Environmental Damage
As with other food production methods, environmental issues arise with poor management.
Organisms create waste which pollute water.
Depletion of water resources.
Destruction of wetlands.

69. Livestock
Animals raised to be sold for profit.

70. Developing Countries
Rely on livestock for food, wool, leather, eggs, to pull carts and plows.

71. Ruminants
Those animals that are cud-chewing and have three-or four –chambered stomachs.

72. Ruminants
Ruminants have microorganisms in their intestines that aid in digesting plant materials that humans cannot breakdown.
When we consume meat, we are digesting the plant material that we cannot obtain from plants ourselves.

73. Poultry
Since 1961, the chicken population worldwide has increased greater than any other livestock population.

74. What is it good for?
The meat and eggs provide a source of essential amino acids, the building block of proteins.