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CHAPTER 18

CHAPTER 18. FOOD RESOURCES: A CHALLENGE FOR AGRICULTURE. NUTRITIONAL REQUIREMENTS Men: ~2,500 kcal/day Women: ~2,000 kcal/day. Interesting Facts… 100 species of plants are commercially grown to meet nutritional needs

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CHAPTER 18

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  1. CHAPTER 18 FOOD RESOURCES: A CHALLENGE FOR AGRICULTURE

  2. NUTRITIONAL REQUIREMENTSMen: ~2,500 kcal/day Women: ~2,000 kcal/day

  3. Interesting Facts… • 100 species of plants are commercially grown to meet nutritional needs • 16 lbs of grain to produce 1 lb of edible meat (90% of US grain is grown for animal feed) • 20x increase in the amount of calories available & 8 fold increase in amount of protein available if we consumed grain directly

  4. Malnutrition86 countries are considered food-deficient Can’t produce enough food or afford to import food to feed pop. • Undernourished: • Consume less than the daily required calories for an extended period • Health and stamina decline sometimes death. • 1/3 of all children under 5 in developing countries (WHO) • Malnourished: • Receive enough calories, but do not receive enough specific, essential nutrients such as protein, vitamin A, iodine etc. • Rice: enough cal, but lack needed protein, lipids & minerals • Susceptible to disease & have less strength- kids do not dev. well • Affects cognitive development- kids do worse in school • 3 Billion people worldwide are malnourished (WHO) • Overnourished: • People that eat in excess- diet high in saturated fat, sugar & salt • Diabetes & heart disease prevalent as well as cancers • WHO estimates 55% of developed pop is over-nourished.

  5. Common diseases of malnutrition • Marasmus: progressive emaciation caused by • a diet low in total calories & protein • Common in children of poor families in • developing countries/or POWs • Slow growth & muscle atrophy • Kwashiorkor: malnutrition resulting from protein deficiency. • Common among children • Edema (fluid retention & swelling), • stunted growth, sometimes mental retardation • Typical feature: pronounced swelling • of the abdomen

  6. Producing enough food • Our yield has increased, but so has our population…. washout • Global food production can be increased in the short term, but the long term solution to food supply problems is to control population • Famines • Crop failures caused by drought, war, flood or catastrophic event may result in a severe food shortage. • Worst Famine was in 1983-1985 in Africa (Ethiopia & Sudan) • 1.5 million people died of starvation • Somalia (1993)- drought caused political unrest killing 2 million • UN intervention to stop warring factions from stealing relief food sent • North Korea- late 1990’s killed over 2 million • Several years of floods & drought wiping out farming

  7. World Grain Carryover Stocks:the amounts of rice, wheat, corn and other grains remaining from previous harvests as estimated at the start of a new harvest. • Think of it like a bank account… • A measure of world food security where all people have • access at all times to adequate amounts and kinds of food needed • Poverty & Food: Providing enough food for all people is complicated by poverty, problems of distribution, and cultural acceptance of nutritious but unfamiliar foods. • Food producing nations cannot simply give food away indefinitely.

  8. The cost of food for one week Compare # of family members Cost of food for 1 week Amount of food for 1 week Types of food for 1 week

  9. Germany : The Melander family of BargteheideFood expenditure for one week: $500.39

  10. United States : The Revis family of NCFood expenditure for one week: $341.98 US

  11. Japan : The Ukita family of Kodaira CityFood expenditure for one week: $317.25 US

  12. Italy : The Manzo family of SicilyFood expenditure for one week: $260.11 US

  13. Mexico: The Casales family of CuernavacaFood expenditure for one week: $189.09 US

  14. Poland : The Sobczynscy family of Konstancin-JeziornaFood expenditure for one week: $151.27 US

  15. Egypt : The Ahmed family of CairoFood expenditure for one week: $68.53 US

  16. Ecuador : The Ayme family of TingoFood expenditure for one week: $31.55 US

  17. Bhutan : The Namgay family of Shingkhey VillageFood expenditure for one week: $5.03 US

  18. Chad : The Aboubakar family of Breidjing CampFood expenditure for one week: $1.23 US

  19. Principle Types of Agriculture • Industrialized (High-Input Agriculture) • Large inputs of capital and energy (fossil fuels) to produce and run machinery, irrigate crops and produce agrochemicals • Produces high yields enabling forests and natural areas to remain wild • Problems: soil degradation, increase in pesticide resistance • Subsistence Agriculture • Production of enough food to feed oneself and family with little left over to sell or reserve. • Requires a lot of human & animal energy • Many types (next slide)

  20. Types of Subsistence Agriculture Shifting Cultivation Short periods of cultivation are followed by periods of fallow in which land reverts to forest. • Slash-and-Burn: clear small parts of forest to plant crops. Must move to another area ~ 3 yrs. (land intensive) • Nomadic: Livestock is supported by land that is too arid for successful crop growth Intercropping (aka Strip-Cropping) Involves growing a variety of plants simultaneously on the same field. Produce higher yields (pest control). Native Americans used this method very successfully. • Polyculture: several kinds of plants that mature at different times are planted together.

  21. Genetic Diversity • When plants and animals are domesticated, much of the genetic diversity found in the wild pop. is lost • Agriculture protects domesticated plants & animals from pests and disease • Globally, a few agricultural varieties are replacing the hundreds of varieties developed by farmer-breeders over centuries • SEED BANKS!! • Genetic Engineered Crops (GMO): moving genes from one species to another with desirable characteristics • PROS: Require less water/fertilizer, higher yields, less spoilage, faster growth, resistant to disease/drought/ insects • CONS: unknown ecological effects, less biodiversity, harm beneficial insects, mutations with unknown consequences, pesticide resistance.

  22. Increasing Crop Yields: GREEN REVOLUTION Production of more food per acre of cropland by using modern cultivation methods and using the new, high yielding varieties of certain staple crops. • Began in the 1950’s (post-WWII) • METHODS: Planting monocultures, high application of inorganic fertilizers and pesticides as well as extensive irrigation systems • Gave Latin American & Asian countries the chance to produce adequate supplies of food. • Increased yield 200% with only a 25% land usage increase • Second Green Revolution (1970’s) continues today with the use of genetically engineered crops that produce more yield per acre.

  23. Problems with the Green Revolution • Problems: • Made developing countries dependent on imported technology (rather than traditional methods) • Environmental problems such as intensive use of inorganic fertilizers & pesticides • Require a large amount of energy to produce • Building of dams for irrigation • Fossil fuels to produce/run farm equipment • Benefited large land owners but not subsistence farmers • Dependence on small number of genetic varieties • Ex) US Wheat: 50% comes from 9 varieties • LIVESTOCK & the Green Revolution: • Use of hormones & antibiotics are used to increase yield • Unknown human effects- EU currently bans all imports of hormone-treated beef because of health concerns.

  24. Environmental Impact of Agriculture • Agricultural use of fossil fuels & pesticides Air poll. • Untreated waste & chemicals (fert. & pest.) Water poll. • Reduce biological diversity, harm fisheries, inc. nuisance species • Single largest cause of surface water pollution in the US! • Agribusiness: livestock are concentrated in small areas • Air & water pollution- quantity of manure is a severe waste prob. • Ex) Hurricane Fran & hog lagoons: 22 large lagoons spilled into the floodplain and streams causing major fish kills. • Pesticide resistance- forces farmers to use more • Degradation of the future land ability to produce crops. • Soil erosion (1/5 of US farm land is vulnerable to soil erosion) • Habitat Fragmentation decrease biological diversity!

  25. Solutions to Agricultural Problems #1 • Sustainable Agriculture • Cause fewer environmental problems • Relies on benefical biological processes & env. friendly chem. • Farm diversification (crops, animals, fruit, nuts) • Water & energy conservation /use pred.-prey to control pests. • Planting crops appropriate for the area (native) • Organic agriculture- use of NO pesticides; use IPM

  26. Solutions to Agricultural Problems #2 • Genetic Engineering • Taking one specific gene from a cell of one kind of organism and place it into a cell of an unrelated organism . • May produce food plants that are more nutritious, resistant to insect pests and viral diseases or are tolerant to drought, heat, cold herbicides or salty soil. • Can use ANY organism- not traditional breeding • GM crops were cultivated on 75M acres in 2000 • Concern that the inserted genes could spread to weeds or wild relatives of crop plants and harm natural ecosystems.

  27. Genetic Engineering

  28. GMO= GENETICALLY MODIFIED ORGANISM

  29. Fisheries of the World 90% of the world’s total marine catch is FISH 6% clam, oyster, squid, octopus, & other mollusks 3% lobster, shrimp, crab 1% is algae or seaweed Fish & other seafood are highly nutritious because they contain high-quality protein. About 80% of the global ocean pollution comes from human activities on land. Is this a problem???

  30. Types of Fishing • No nation lays claim to the ocean, so resources are more susceptible to overuse ~ TRAGEDY of COMMONS • According to the FAO, 62% of the world’s fish stocks are in urgent need of management action. • Growing human population requiring protein • Technological advances….. Fish don’t have a chance! • Sonar, Radar, Computers, Airplanes, Satellites • Long lines- lines with thousands of hooks. Can be 128 mi long. • Purse-seine: 2000m long used to encircle fish and trap them • Trawl net: funnel shaped net pulled along the bottom. As much as 27 metric tons can be caught at once. Destroy habitat! • Drift net: plastic nets up to 64 km that entangles thousands of fish and other marine organisms. Banned by most countries.

  31. Modern Commercial Fishing Methods Methods have become so successful that many fish species are commercially extinct. Organisms are accidentally caught and killed in addition to the target species. TRAWL BAGS Cod, Flounder, Snapper, Scallops, Shrimp BOTTOM FISH/SHELLFISH LONG LINE Surface: Sharks, Tuna Deep: Cod, Halibut PURSE SEINES Anchovies, Herring, Mackerel, Tuna SURFACE FISH DRIFT NET Salmon, Tuna OPEN WATERS BAD!! 

  32. Fishing Problems Bycatch: dead or dying organisms that are unintentionally caught & discarded. ~25% of the total catch Open Enclosure Policy: organisms within 200 mi of land are under the jurisdiction of the country bordering the ocean. In response to overharvesting. Magnuson Fishery Conservation Act (1977): Established 8 regional fishery mgmt. councils that developed quotas.  Revised in 1996 (Magnuson-Stevens) to protect essential fish habitat for more than 600 fish species, reduce overfishing, rebuild populations & minimize bycatch.

  33. Sustainable McDonalds!

  34. AQUACULTUREThe rearing of aquatic organisms Fastest growing type of food production- 1 out of 3 fish destined for humans comes from fish farms. 6% of all US fish- all striped bass & rainbow trout as well as > ½ the salmon served. To optimize quality of their “crops”, farmers control the diets, breeding cycles & env. conditions of ponds. Try to reduce pollution & keep predators away. Important crops include: seaweeds, oysters, mussels, clams, lobsters & crabs. Developing nations produce more fish by aquaculture than dev. nations.

  35. If coastlines are not used for habitat, other competing uses will take over such as development Produces wastes that pollute adjacent water Causes a net loss of wild fish because many farmed fish are carnivorous. Expensive to set up and run Not profitable for all organisms. Population must be constantly monitored for diseases. Receptivity of animals to domestication ex: lack of territorialism AQUACULTURE PROBLEMS

  36. GROWING BUSINESS….

  37. Solutions to Agricultural Problems Using your knowledge of environmental science from the whole year, what do YOU think are some solutions? WRITE THEM DOWN Discuss with a partner Class Discussion 5 minutes MAXIMUM!!

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