Chapter 18 Food Resources: A Challenge For Agriculture

1. Chapter 18Food Resources: A Challenge For Agriculture

2. Overview of Chapter 18 • Food and Nutrition • World Food Problems • Principle Types of Agriculture • Challenges of Producing More Crops and Livestock • Environmental Impact of Agriculture • Solutions to Agricultural Problems • Fisheries of the World

3. Food and Nutrition2000 kcal -2500 kcal/day • Carbohydrates • Sugars and starches metabolized by cellular respiration to produce energy • Proteins • Large, complex molecules composed of amino acids that perform critical roles in body. Must get essential amino acids from food. • Lipids • Include fats and oils and are metabolized by cellular respiration to produce energy. Most energy. • Vitamins(molecule) and Minerals (elements – iron, calcium)

4. Human Foods

5. World Food Problems • Annual grain production (left) has increased since 1970 • Grain per person has not (right) • South Asia and Sub-Saharan Africa

6. Reasons for not meeting food needs • Growing population • Rising temperatures • Falling water tables and droughts • Ethanol production • More grain is going towards feeding livestock. • Ex: 1 kg of beef requires 7 kg grain

7. Our Diet vegetarians Non-vegetarians Easy source of protein – meat, milk, eggs Livestock requires more land, more energy, more water Risk of heart disease • More sustainable land use • Harder to get essential amino acids Rice and beans = nutritious Just rice = not nutritious

8. World Food Problems • Poverty and Food • 1.3 billion people are so poor they cannot afford proper nutrition • Undernourished vs. malnourished • Kwashiokor – protein deficient • More common in • Rural than urban areas • Infants, children and the elderly • Economics and Politics • Cost money to store, produce, transport and distribute food • Getting food to those who need it is political

9. Types of Agriculture Industrialized agriculture • High-input • High yields • Fossil fuels: machinery, inorganic fertilizers, pesticides, irrigation • HDC

10. Types of Agriculture • Subsistence Agriculture • Low yields (enough for family) • Energy from humans/work animals • Require lots of land • Examples: • Shifting cultivation • Slash and burn agriculture (deforestation) • Nomadic herding

11. Organic farming • No pesticides, synthetic fertilizers genetically modified crops

12. Challenges of Producing More Crop and Livestock • Domestication • causes a loss of genetic diversity • Farmer selects and propagates plants/animals with desirable agricultural characteristics • Many high yielding crops are genetically uniform • High likelihood that bacteria, fungi, viruses, etc. will attack and destroy entire crop

13. Challenges of Producing More Crop and Livestock • Increasing Crop Yield • Developedcountries: • fertilizers • Pesticides • Selective breeding Graph = wheat

14. Case-In-Point:Green Revolution • 1960s – more grain (wheat/rice) per acre • Selective breeding • Use of fertilizers and irrigation made it possible to grow crops in more places • Started in Mexico, spread to US, India, China

15. Case-In-Point:Green Revolution • Problems: • High energy costs • Require fossil fuels to make fertilizers, build/run tractors, construct dams/canals, pump water from groundwater • Environmental degradation due to inorganic fertilizers and pesticides • Led to overpopulation

16. Check for understanding • 4 – • 3 – • 2 - • 1 -

17. Challenges of Producing More Crop and Livestock • CAFOs (concentrated animal feeding operations): less land, but more antibiotics. Waste disposal • Increasing Livestock Yields: • Antibiotics • Problems with increased bacteria resistance (evolution) • Hormone supplements (rBGH) • US and Canada do this: increase growth and milk production. • Europe does not citing human health concerns (Precautionary Principle)

18. Antibiotic Use and Resistance

19. Environmental Impacts of Agriculture • High use of fossil fuels • Air pollution • Untreated animal wastes and agricultural chemicals • Water pollution • Harms fisheries • Insects, weeds, and disease-causing organisms developing resistance to pesticides • Contaminate food supply • Kills beneficial soil organisms

20. Environmental Impact of Agriculture • Land degradation • Decreases future ability of land to support crops or livestock • Erosion – decreases soil fertility, sediments pollute water • Compacting soil, waterlogging, salinization • Habitat fragmentation, deforestation • habitat loss • erosion • Decreases biodiversity and gene pool

21. Environmental Impact of Agriculture • Cultivating marginal lands • Irrigating dry land • Cultivating land prone to erosion • Water consumption • Ex: Ogallala Aquifer = nonrenewable resource b/c water so old • Drip irrigation!

22. Solutions to Agricultural Problems- Sustainable Agriculture

23. Sustainable Agriculture(alternative or low-input agriculture) • Examples: • Pest control: natural Predator-prey relationships instead of pesticides, crop selection • Reduce erosion: conservation tillage and contour plowing • Reduce fertilizers – crop rotation, animal manure, supplying nitrogen with legumes

24. Sustainable Agriculture(alternative or low-input agriculture) • Integrated Pest Management (IPM) • Limited use of pesticides by using knowledge of the life cycles of pests, pheromones, trapping, and then targeted pesticide use; allowing some pests is fine • Organic agriculture • No pesticides, synthetic fertilizers genetically modified crops

25. Check for understanding • 4 – I can cite at least 2 methods for each of the farming issues below • 3 – I can cite at least 1 method to farm sustainably for each of the following farming issues: pesticides, synthetic fertilizers, erosion, soil salinization, water consumption • 2 - I know a few examples, but not one for each issue. • 1 – I know what sustainable means.

26. Genetic Engineering • Transferring genes of desirable trains from one organism into the DNA of another

27. Genetically Modified Organisms (GMOs) • Faster than selective breeding • 1st GM food on market – Flavr Savr Tomato • Typical goals • Increase nutrition – ex: golden rice • Pest resistance – ex: Bt corn • Resistant to other environmental stress – drought, salty or acidic soils • GE in animals • Create hormones to increase growth

28. Genetically Modified Organisms (GMOs) • Determined safe by FDA • Concerns: allergies, reduced biodiversity if introduced to wild • Labeling: none in US

29. Check for understanding • 4 – I can explain the pros and cons of GE food. • 3 – I understand multiple reasons why GE food is developed AND multiple reasons why people are concerned about it. • 2 - I understand either why GE food is developed or why people are concerned about it, but not both. • 1 – I know what GE food is.

30. Fisheries of the World- Problems • No nation lays claim to open ocean • susceptible to overuse • Tragedy of the Commons • Overharvesting • Many species are at point of severe depletion • Food for growing human population • Technological advances in fishing gear

31. Fisheries of the World- Problems • Longlines – thousands of hooks • Purse-sein nets • Trawl net – dragged along the bottom • Spotter airplanes • Overfishing reduces gene pool of existing fish • By-catch DIE

32. Fisheries of the World- Laws • Magnuson-Stevens Fishery Conservation and Management Act • EX: Set quotas, limits # of boats • Marine Mammal Protection Act

33. Fisheries of the World- Problems • Ocean Pollution - dumping ground • Oil • Heavy metals • Deliberate litter dumping • Stormwater runoff from cities and agricultural areas – biggest pollution source • Coastal areas degraded by development (many fish depend on tidal marshes, mangrove swamps, estuaries for spawning and feeding)

34. Aquaculture(ex: shrimp,salmon) • Raising of aquatic organisms for human food • Protein!! • Negatives: • Locations of fisheries may hurt natural habitats – compete for shore space, destroy mangroves, destroy breeding grounds for fish • Produce waste that pollutes adjacent water • Often fed fish from the wild • Expensive facility • Easy spread of disease  antibiotics

35. Check for understanding • 4 – I can teach the next class. • 3 – I understand at least 2 fishing techniques that may lead to overfishing, the laws that serve to protect fisheries, and the pros and cons of aquaculture. • 2 – I understand but need to re-read my notes. • 1 – I know why overfishing is bad.