1. Chapter 13 Food, Soil Conservation, and Pest Management

2. Golden Rice -Grains of Hope or an Illusion?  Genetically engineered strain of rice containing beta-carotene.  Can inexpensively supply vitamin A to malnourished.  Critics contend that there are quicker and cheaper ways to supply vitamin A.  Scientists call for more evidence that the beta-carotene will be converted to vitamin A by the body. Figure 13-1

3. FOOD SECURITY & NUTRITION  1/3 globally has a deficiency of one or more vitamins and minerals, especially vitamin A, iodine (causes goiter - enlargement of thyroid gland), & iron. Marasmus Kwashiorkor Figure 13-2

4. FOOD PRODUCTION  3 Systems for Food Supply: 1) croplands 2) rangelands, & 3) aquaculture/fisheries  Wheat, rice, and corn provide more than half of the world’s consumed calories.  Primary animals for nutrition include beef, pork, & chicken.

5. Major types of agriculture  1) Traditional subsistence – just enough for family  2) Traditional intensive – feed family & make income – use labor force  3) Plantation – cash crops (bananas, coffee, sugar cane) – sell to developed areas  4) Industrialized – high energy, water, fuel, fertilizer, pesticides – monoculture

6. Fig. 13-4, p. 275 Plantation agriculture Shifting cultivation Industrialized agriculture No agriculture Intensive traditional ag. Nomadic herding

7. Industrial Food Production: High Input Monocultures  Industrialized Livestock production: Feedlots are used to fatten up cattle before slaughter. Most pigs and chickens live in densely populated pens or cages. Most livestock are fed grain grown on cropland. Systems use a lot of energy and water and produce huge amounts of animal waste.

8. Industrialized Food Production in the United States  The U.S. uses industrialized agriculture to produce about 17% of the world’s grain. Relies on cheap energy to run machinery, process food, produce commercial fertilizer and pesticides.  About 10 units of nonrenewable fossil fuel energy are needed to put 1 unit of food energy on the table.

9. Industrialized Food Production in the United States  Industrialized agriculture uses about 17% of all commercial energy in the U.S. and food travels an average 2,400 kilometers from farm to plate. Figure 13-7

10. Traditional Agriculture: Low Input Polyculture Polyvarietal cultivation: planting several genetic varieties. Intercropping: two or more different crops grown at the same time in a plot. Agroforestry: crops and trees are grown together. Polyculture: different plants are planted together.

11. Global Outlook: Soil Erosion  Soil is eroding faster than it is forming on more than one-third of the world’s cropland. Figure 13-10

12. Desertification: Degrading Drylands  About one-third of the world’s land has lost some of its productivity because of drought and human activities that reduce or degrade topsoil. Figure 13-12

13. Salinization and Waterlogging  Repeated irrigation can reduce crop yields by causing salt buildup in the soil and waterlogging of crop plants. Figure 13-13

14. SUSTAINABLE AGRICULTURE THROUGH SOIL CONSERVATION  Fertilizers can help restore soil nutrients, but runoff of inorganic fertilizers can cause water pollution. Organic fertilizers: from plant and animal (fresh, manure, or compost) materials. Commercial inorganic fertilizers: Active ingredients contain nitrogen, phosphorous, and potassium and other trace nutrients.

15. THE GREEN REVOLUTION AND ITS ENVIRONMENTAL IMPACT  Since 1950, high-input agriculture has produced more crops per unit of land.  In 1967, fast growing dwarf varieties of rice and wheat were developed for tropics and subtropics. Figure 13-17

16. Increasing World Crop Production  Crossbreeding & artificial selection  Genetic engineering  Genetically modified foods (GMF’s)  Green Revolution techniques  Introducing new foods/changing popularity  Working more arable (farmable) land

17. Mixing Genes  Genetic engineering involves splicing a gene from one species and transplanting the DNA into another species. Figure 13-19

18. THE GENE REVOLUTION  The winged bean, a GMF, could be grown to help reduce malnutrition and the use of large amounts of inorganic fertilizers. Figure 13-20

19. PRODUCING MORE MEAT  ½ of world’s meat comes from rangeland/pasture.  The other half is produced under factory-like conditions (feedlots).  A typical American’s diet would only support 2.5 billion people (we have over 6.1 billion now).

20. To Manage Rangelands: 1)Fence off riparian zones. 2)Move livestock around the range. 3)Supplement feed with vitamins/minerals. 4)Use water holes, salt blocks to entice animals into underused areas 5)Use a variety of animals that graze at different heights.

21. PRODUCING MORE MEAT  Efficiency of converting grain into animal protein. Figure 13-22

22. CATCHING AND RAISING MORE FISH AND SHELLFISH  After spectacular increases, the world’s total and per capita marine and freshwater fish and shellfish catches have leveled off. Figure 13-23

23. CATCHING FISH AND SHELLFISH  1) Trawling (shrimpboats)  2) Purse-seine fishing (Nemo)  3) Longlining – miles of lines behind boats  4) Drift-net/gill net – swim into net & get trapped  5) Fish farming/ranching (aquaculture)

24. Government Policies and Food Production  Governments use three main approaches to influence food production: Control prices to keep prices artificially low. Provide subsidies to keep farmers in business. Let the marketplace decide rather than implementing price controls.

25. TYPES OF PESTICIDES  Insecticides  Herbicides  Fungicides  Rodenticides  1 st Generation – natural substances – S, Pb, Hg, As – nicotine, pyrethrum, rotenone – around since 500 B.C.  2 nd Generation – synthetic organic compounds – broad or narrow spectrum

26. PROTECTING FOOD RESOURCES: PEST MANAGEMENT  Today’s pesticides are 10x more toxic than in the 1950s. Lawns get 10x more pesticides than crops. Figure 13-28

27. Individuals Matter: Rachel Carson  Wrote Silent Spring which introduced the U.S. to the dangers of the pesticide DDT and related compounds to the environment. DDT was banned in 1972 in the US but is still used in developing countries. Figure 13-A

28. The ideal Pesticide and the Nightmare Insect Pest  The ideal pest-killing chemical has these qualities: Kills only target pest. Does not cause genetic resistance in the target organism. Disappears or breaks down into harmless chemicals after doing its job. Is more cost-effective than doing nothing.

29. Pros/Cons of Pesticides  Save human lives (malaria, plague, typhus)  Increases food supply & decreases costs  Works faster than alternatives  May cause genetic resistance  May kill non-target species  Develops pesticide treadmill  Pesticides move through ecosystems  Human health threats Figure 13-29

30. Pesticide Protection Laws in the U.S. FIFRA – all commercial pesticides must be approved by the EPA. The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides. Tolerance level – how much residue can be on the crop when consumers eat the crop. Food Quality & Protection Act (FQPA) – company must demonstrate that ingredients are safe for kids

31. Alternatives to Chemical Pesticides 1) Soaps 2) Hot water 3) Pick bugs off 4) Squash the bugs & leave them on the plant 5) Neem tree oil 6) Boric acid 7) Diatomaceous earth 8) Natural predators 9) Repellant plants (peppermint, salvia, marigolds) 10) Vinegar sprays 11) Vacuum

32. Other Ways to Control Pests 12)Biopesticides (Bt) 13)Epsom salts 14)Insect birth control (sterilize males) 15)Hormones & pheromones 16)Ionizing radiation Figure 13-31

33. Other Ways to Control Pests  Genetic engineering can be used to develop pest and disease resistant crop strains.  Both tomato plants were exposed to destructive caterpillars. The genetically altered plant (right) shows little damage. Figure 13-32

34. Integrated Pest Management  1) Set economic threshold  2) Field monitor pests  3) Use biological agents  4) Chemical pesticides (last resort)  Don’t get rid of pests, just take them to a manageable level

35. Sustainable Agriculture  Results of 22 year study comparing organic and conventional farming. Figure 13-34

36. Bhopal, India  1984 – Union Carbide pesticide plant – 40 tons of cyanide gas released from storage tanks – 7000 – 16,000 people killed – 50,000 – 60,000 injured