1. Food Resources See Miller Chapter 12 Issues and Impacts of Agriculture ENVS 1 Oct. 14, 2002

2. Main Topics  Methods of producing food  Increasing food production  Environmental effects of food production  Issues of sustainability

3. Sources of food worldwide  Of 30,000 edible plants, only 15 spp. supply 90% of our food  Of 30,000 edible plants, only 15 spp. supply 90% of our food  Primary plants: wheat, corn, and rice Provide > ½ calories people consume  Primary plants: wheat, corn, and rice Provide > ½ calories people consume  Primary animals: cattle, pigs, and chicken 2ndary: Eggs, milk & cheese  Primary animals: cattle, pigs, and chicken 2ndary: Eggs, milk & cheese

4. Major Types of Agriculture  Traditional subsistence  Shifting cultivation  Nomadic herding  Traditional subsistence  Shifting cultivation  Nomadic herding  Traditional intensive  Plantation  Industrialized

5. Fig. 12.3a, p. 264 Industrialized agriculture in developed countries Intensive traditional agriculture in developing countries Land Labor Capital Fossil fuel energy Land Labor Capital Fossil fuel energy

6. Fig. 12.3b, p. 264 Shifting cultivation in tropical forests in developing countries Nomadic herding in developing countries Land Labor Capital Land Labor Capital

7. Industrialized agriculture Shifting cultivation Plantation agriculture Nomadic herding Intensive traditional agriculture No agriculture World Food Production Fig. 12.2, p. 263

8. Fig. 12.8a, p. 268 2,000 1,500 1,000 500 0 Grain production (millions of tons) 1950196019701980199020002010 Total World Grain Production

9. Fig. 12.8b, p. 268 400 350 300 250 150 Per capita grain production (kilograms per person) 1950196019701980199020002010 Per Capita World Grain Production 200

10. Green Revolutions First green revolution (developed countries) First green revolution (developed countries) Second green revolution (developing countries) Second green revolution (developing countries) Major International agricultural research centers and seed banks Major International agricultural research centers and seed banks Fig. 12.4, p. 265

11. Producing Food by Green- Revolution Techniques  High-input monoculture  Selectively bred or genetically-engineered crops  High inputs of fertilizer  Extensive use of pesticides  High inputs of water  Increased intensity and frequency of cropping

12. Heavier heads required: more fertilizer, water, hybrids with shorter stalks (to prevent lodging) Higher density plantings required: more fertilizer, constant water, hybrids with smaller root system More plantings per year required: more fertilizer, year round water, pesticides To increase rice yields: More, bigger grain per stalk (heavier head) More stalks per acre (higher density) More plantings per year More fertilizer, water, pesticides & hybrid seed required: more energy, esp. from fossil fuels more cash, especially US dollars

13. Results of Green Revolution: Mixed Higher yields per acre when inputs available Lower yields when inputs unavailable Increased dependence on cash economy Increased dependence on fossil fuel Increased imports of inputs Income disparity?? Migration to cities??

14. Unintended consequences: Killer Bees Mild-mannered, low honey producing Italian bee X Aggressive, high honey producing African bee? Hope for a mild- mannered, high producing bee Instead, got an aggressive, low producing bee Worse yet – it escaped, and is interbreeding with other bees making them aggressive & low producing too!

15. Environmental Effects of Food Production  Biodiversity loss  Soil degradation  Air pollution  Water pollution  Human health

16. Fig. 12.10a, p. 271 Biodiversity Loss Loss and degradation of habitat from clearing grasslands and forests and draining wetland Invasive species out competing natives Killing of wild predators to protect livestock Loss of genetic diversity from replacing thousands of wild crop strains with a few monoculture strains Soil Erosion Loss of fertility Salinization from irrigation Desertification

17. Fig. 12.10b, p. 271 Air & Climate Greenhouse gas emissions from fossil fuel use Other air pollutants from fossil fuel use Pesticide drift from spraying Dust / airborne particulates Weather alteration from large scale clearing Water Aquifer depletion Water diversions Increased runoff and flooding from land cleared to grow crops Sediment pollution from erosion Fish kills from pesticide runoff Surface and groundwater pollution from pesticides, fertilizers & livestock Overfertilization (eutrophication) of lakes and slow-moving rivers from runoff of nitrates and phosphates from fertilizers, livestock wastes, and food processing wastes

18. Fig. 12.10c, p. 271 Human Health Nitrates in drinking water Pesticides residues in drinking water, food, and air Contamination of drinking and swimming water with disease organisms from livestock wastes Bacterial contamination of meat Farm worker exposure & working conditions

19. Food Production since Green Rev  Rapid increases in total production  Prices decreasing  Shortages in developing countries  Approaching limits on meat production

20. Increasing World Crop Production  Crossbreeding and artificial selection  Genetically modified organisms (GMOs)  Continued Green Revolution techniques  Introducing new foods  Working more land

21. Alternative Solutions: Sustainable Agriculture  Low-input agriculture  Organic farming  Non-meat alternatives  Research in sustainable techniques See Fig. 12-21 p. 291

22. Vermont: A case of agricultural innovation and environmental degradation Developing & disseminating new breeds: Merino sheep Jersey cow Morgan horse Green Mountain potato

23. Soil failure and the sheep boom Soils, crop yields already in decline Merino sheep introduced 1811 & breeding ↑ yields 143% Wool tariffs 1824 Civil War 1860s (wool blankets!) 1.5 million sheep in VT in mid-1800s Hillsides denuded After Civil War, sheep industry failed in VT Farms abandoned

24. What’s was next for Vermont? 5 cows earn $357.50 per year, while 40 sheep net only $40 per year -- Vermont Board of Agriculture, 1868

25. And Cows still with us. 1525 of VT’s 6800 farms are dairy Served New England market for milk, butter & cheese. In 1960, 10,000 dairy farms produced half the milk that the current 1525 farms produce now! Average herd size ↑↑ Production per cow ↑↑ Jersey cows bred in VT helped make VT butter and cheese famous! Breeding & other ag research remain import to VT’s economy and environment.

26. In Summary: Supplying food for the world’s growing population was and still is an issue. Policy and research play a big role. Efforts to increase production have focused on: –Improved varieties thru breeding and genetic engineering –Inputs, esp. chemicals, energy and water Agriculture has multiple impacts on the environment and human health Sustainable agricultural techniques are growing but far behind conventional