1. Food and Agriculture

2. Land Use 11% of the earth’s land is used in agricultural production
Less land cultivated in NA now than 100 years ago
Why?

3. Types of Food Production
Traditional subsistence agriculture
Mostly human and animal labor
Enough crop for a family’s survival
Where does this exist today?

4. Types of Food Production
Industrialized agriculture
high input agriculture
Example: Plantation agriculture
Used in tropical developing nations
Cash crops grown for export
May provide non-food products (latex)
Provide products that do not make up primary nutrition (tea, coffee)

5. Ecosystem created by agricultural practices
Agroecosystems
Ecosystem created by agricultural practices
characterized by low
Genetic diversity
Species diversity
Habitat diversity

6. Agroecosystems Differ from natural ecosystems in five major ways:
Attempts to stop ecological succession
Species diversity is low
Negative effects?
Plant crops in an orderly fashion
pest control more difficult
Simple food chains
Plowing
↑ erosion
Nutrient loss

7. Farm Numbers

8. Number of People Fed Annually By One Farmer

9. Food Supply
15 to 20 species provide vast majority (90%) of man’s food needs
Wheat, rice, corn, potatoes, barley
Wheat and rice supply ~60% of human caloric intake
90% of grain grown in NA is used to feed livestock

10. Meat Sources
20% of the richest countries consume 80% of the world’s meat
About 90% of the grain grown in the United States is used for animal feed
16 lbs of grain → 1 lb of meat

11. World Food Supply and the Environment
Enough food, unevenly distributed
815 million people do not have enough to eat
Parts of Africa, southeast Asia
In richest countries, 11 million do not have enough to eat

12. Nutritional Requirements
Malnutrition
Under-nutrition
Iron deficiency
Leads to anemia
Red meat, eggs, legumes, and green vegetables are all good sources of iron.
Vitamin A deficiencies
Can cause blindness

13. Malnutrition Cont. Over-nutrition
Most common dietary problem in wealthy countries
According to U.S. Surgeon General:
62% of Americans are overweight.
33% are obese
Famine
Causes?

14. Risk of Inadequate Nutrition

15. Land Use and Degradation
Overgrazing and soil erosion
Eliminates millions of acres a year
Desertification-degrading once fertile land into desert
Surface runoff
Dry surface reflects heat, changing wind patterns

16. Global Soil Degradation

17. Mechanisms of Erosion Intensive farming practices: Salinization
Waterlogging
Impairs root growth, roots cannot get oxygen
No crop rotation
Removal of windbreaks
Continued monocultures

18. Alternatives to Industrial Farming Methods
Sustainable Agriculture
Through soil conservation
Intercropping
Crop rotation
Agroforestry
Contour Plowing

19. Soil Conservation Cont.
Providing Ground Cover
No till agriculture
Plant cover crops
Improved irrigation
Drip irrigation

20. New vs. Old Agriculture

21. Methods to Increase Food Supply
Food distribution modification
Teach locals
In the 1960s:
Green Revolution
Mechanization
Monocultures of selectively bred or genetically engineered high yield variety of crops (rice, corn, wheat)
Corn yields jumped from 25 bushels per acre to 130 per acre in last century.
Using high inputs of fertilizer, pesticides, and water on crops to produce high yields
Increasing the intensity and frequency of cropping

22. Genetic Engineering Genetically Modified Organisms (GMO’s)
Crops resistant to drought, frost, diseases, pests, etc.
Animals that grow faster, gain weight on less food, produce more milk, etc.
Estimated at least 70% of all processed foods in NA contain transgenic products.

23. Is Genetic Engineering Safe ?
Environmental and consumer groups have campaigned against transgenic organisms.
“Frankenfoods”
Opponents fear traits could spread to wild varieties
U.S. Food and Drug Administration declined to require labeling of foods containing GMO’s.
New varieties are “substantially equivalent” to related traditionally-bred varieties.

24. How Would You Vote?
Do the advantages of genetically engineered foods outweigh their disadvantages?
Should labeling of GMOs be required?

25. Increasing Food Supply: Producing More Meat
½ of the world’s meat is produced by livestock grazing on grass.
½ half is produced under factory-like conditions (feedlots).
Concentrated animal feeding operations (CAFOs)
High density, confined or allowed very little moving room
A CAFO may contain as many as 2500 hogs or 55,000 turkeys in a single building
Pros?

27. Increased meat production
Trade-Offs
Animal Feedlots
Advantages
Disadvantages
Increased meat production
Need large inputs of grain, fish meal, water, and fossil fuels
Higher profits
Concentrate animal wastes that can pollute water
Less land use
Reduced overgrazing
Reduced soil erosion
Antibiotics can increase genetic resistance to microbes in humans
Help protect biodiversity
Fig , p. 289

28. Catching and Raising More Fish
Fisheries
third major food-producing system
~55% of annual commercial catch from ocean
Overfishing
Tragedy of the commons
Bycatch
~45% from use of aquaculture to raise marine and freshwater fish

29. Fishing methods

30. Raising More Fish Aquaculture: Aquatic Feedlots

31. 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
Destroys mangrove forests and estuaries
Can reduce overharvesting of conventional fisheries
Uses grain to feed some species
Low fuel use
Dense populations vulnerable to disease
High profits
Tanks too contaminated to use after about 5 years
Profits not tied to price of oil

32. Solutions Managing Fisheries
Fishery Regulations
Set catch limits well below the maximum
sustainable yield
Improve monitoring and enforcement
of regulations
Economic Approaches
Sharply reduce or eliminate fishing subsidies
Charge fees for harvesting fish and shellfish
from publicly owned offshore waters
Certify sustainable fisheries
Protected areas
Establish no-fishing areas
Establish more marine protected areas
Rely more on integrated coastal
management
Consumer Information
Label sustainably harvested fish
Publicize overfished and threatened species
Bycatch
Use wide-meshed nets to allow escape of
smaller fish
Use net escape devices for seabirds and
sea turtles
Ban throwing edible and marketable fish back
into the sea
Aquaculture
Restrict coastal locations for fish farms
Control pollution more strictly
Depend more on herbivorous fish species
Nonnative Invasions
Kill organisms in ship ballast water
Filter organisms from ship ballast water
Dump ballast water far at sea and replace with
Deep-sea water

33. Sustainable Animal Farming
Free-range
Organic
Smaller scale farms

34. Buy Local!
The average American foodstuff travels an estimated 1500 miles before being consumed.