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Chapter 11 Feeding the World

Chapter 11 Feeding the World. Global Undernutrition. Nutritional Requirements. Undernutrition- not consuming enough calories to be healthy. Malnourished- a persons diet lacks the correct balance of proteins, carbohydrates, vitamins, and minerals even though they get enough calories.

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Chapter 11 Feeding the World

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  1. Chapter 11 Feeding the World

  2. Global Undernutrition

  3. Nutritional Requirements • Undernutrition- not consuming enough calories to be healthy. • Malnourished- a persons diet lacks the correct balance of proteins, carbohydrates, vitamins, and minerals even though they get enough calories. • Overnutrition- too many calories and improper foods that causes a person to become overweight.

  4. American Diet • Quote from Robert Lustig, professor of endocrinology at UCSF • “How many times did you have to introduce a savory food to a baby before they would accept it? On average 13 times, that's what science says. But if the food is sweet, how many times? Just once.” • So why have humans evolved to enjoy sugar and what is wrong with us? Quote source: http://www.npr.org/2013/01/11/169144853/the-fallacies-of-fat

  5. Annual Meat Consumption

  6. Global Grain Production, 1950-2006

  7. Reasons for Undernutrition and Malnutrition • Poverty • Political and economic factors • Agricultural resources being diverted to feed livestock and poultry rather than people

  8. The Green Revolution • New management techniques and mechanization as well as the triad of fertilization, irrigation, and improved crop varieties. This has increased food production dramatically.

  9. Irrigation Problems • Waterlogging • when the soil remains under water for prolonged periods which impairs root growth because the roots cannot get oxygen. • Salinization • when the small amounts of salts in irrigation water become highly concentrated on the soil surface through evaporation.

  10. Fertilizers • Organic fertilizers • organic matter from plants and animals. Typically made from animal manure that has been allowed to decompose. • Inorganic fertilizers (synthetic) • fertilizers that are produced commercially. This is usually done by combusting natural gas, which allows nitrogen from the atmosphere to be fixed and captured in fertilizer.

  11. Monocropping • Growing a large amount of a single species of plant.

  12. Pesticides • Pesticide • a substance that kills or controls organisms that people consider pests. • Two categories of pesticides • Insecticide • Herbicides

  13. Pesticides • Broad-spectrum pesticides • designed to kill many different types of pests. • Selective pesticides • designed to kill a narrower range of organisms.

  14. Pesticides • Persistent • pesticides that remain in the environment a long time. • Nonpersistent • pesticide that breaks down relatively rapidly, usually in weeks to months.

  15. Pesticides • Resistance • pest populations may evolve resistance to a pesticide over time. These are said to be resistant. • Pesticide treadmill • the cycle of pesticide development followed by pest resistance, followed by development of a new pesticide.

  16. Bees and Pesticides • http://www.ted.com/talks/noah_wilson_rich_every_city_needs_healthy_honey_bees.html • What is behind the decline of bees? • Here is the latest theory:

  17. Soil • Soil is important because it • Is a medium for plant growth • Serves as a filter for water • A habitat for living organisms • Serves as a filter for pollutants

  18. The Formation of Soil • Factors that determine the formation of soil: • Parent material • what the soil is made from influences soil formation • Climate • what type of climate influences soil formation • Topography • the surface and slope can influence soil formation • Organisms • plants and animals can have an effect on soil formation • Time • the amount of time a soil has spent developing can determine soil properties.

  19. The Formation of Soil • Parent Material- the rock material from which soil is derived.

  20. Soil Horizons • As soils form, they develop characteristics layers.

  21. Soil Horizons • O horizon- (organic layer) composed of the leaves, needles, twigs and animal bodies on the surface. • A horizon- (topsoil) the zone of organic material and minerals mixed together. • B horizon- (subsoil) composed primarily of mineral material with very little organic matter • C horizon- (parent material) the least weathered horizon and is similar to the parent material.

  22. Physical Properties of Soil • Texture- the percentage of sand, silt and clay the soil contains.

  23. Physical Properties of Soil • Porosity- how quickly the soil drains (which depends on its texture)

  24. Chemical Properties of Soil Cation exchange capacity- the ability of a soil to adsorb and release cations, positively charged mineral ions. Soil bases- calcium, magnesium, potassium and sodium Soil Acids- aluminum and hydrogen Base saturation- the proportion of soil bases to soil acids

  25. Biological Properties of Soil • Many organisms are found in the soil including fungi, bacteria, protozoans, rodents and earthworms. 28

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