Food and Agriculture

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

3. Types of Food Production • Traditional subsistence agriculture • mostly human and animal labor • Produces only enough crops for a family’s survival • Africa, Asia, South America

4. Types of Food Production • Industrialized agriculture (high input agriculture) • Large amount of fossil fuel energy, water, fertilizers and pesticides to produce large quantities of monocultures • 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. 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: • Farming attempts to stop ecological succession • Species diversity is low • Monoculture ↓ soil fertility • Plant species (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 • Food production depends upon favorable environmental conditions

12. Food Distribution • Food is not distributed equally due to: • Soil and climate differences • Political and economic power • Average per capita income throughout the world

13. Malnutrition/Famines • Malnutrition • Undernutrition • Overnutrition • Famine • Environmental conditions are immediate trigger, but politics and economics are often underlying problems. • Famine conditions • Major droughts -- Political instability • Population sizes -- Land Seizures • Massive immigration -- Distribution breakdown • Floods -- Chaos in economy • Wars

14. Risk of Inadequate Nutrition

15. Undernutrition Problems • Iron deficiency • Most common • Leads to anemia • Red meat, eggs, legumes, and green vegetables are all good sources of iron. • Vitamin A deficiencies • Can cause blindness

16. Obesity • Most common dietary problem in wealthy countries • According to U.S. Surgeon General: • 62% of Americans are overweight. • 33% are obese.

17. 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

18. Global Soil Degradation

19. Mechanisms of Erosion • Wind and water are erosive forces • Intensive farming practices: • Salinization • Waterlogging • Impairs root growth, roots cannot get oxygen • No crop rotation • Removal of windbreaks • Continued monocultures

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

21. Soil Conservation Cont. • Providing Ground Cover • No till agriculture • Plant cover crops • Improved irrigation and utilization of water • Drip irrigation

22. New vs. Old Agriculture

23. Methods to Increase Food Supply • Food distribution modification • Teach locals • In the 1960s: • Green Revolution-increased yields per unit of area of cropland • Mechanization • Monocultures of selectively bred or genetically engineered high yield variety of key 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

24. 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.

25. 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.

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

27. 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

29. 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. 13-21, p. 289

30. Sustainable Animal Farming • Free-range • Organic • Smaller scale farms

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

32. Catching and Raising More Fish • Fisheries • third major food-producing system • ~55% of annual commercial catch from ocean • ~45% from use of aquaculture to raise marine and freshwater fish

33. Fishing methods

34. Catching and Raising More Fish • Commercial fish amounts have been declining since 1980 • Overfishing • Tragedy of the commons • Bycatch

35. Raising More FishAquaculture: Aquatic Feedlots • Raising large numbers of fish and shellfish in ponds and cages in a controlled environment and harvesting them in captivity.

36. 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

37. 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