Copyright  ©  The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 7 Lecture Outline
Learning Outcomes After studying this chapter, you should be able to answer the following questions: <ul><li>•  How have g...
We can’t solve problems by using the same kind of thinking we used when we created them. –Albert Einstein 7-
7.1 Global Trends in Food and Nutrition <ul><li>Food production has been transformed from small-scale, diversified, family...
Hunger around the world 7-
Food security is unevenly distributed <ul><li>Four decades ago, hunger was one of the world’s most prominent, persistent p...
Food security is unevenly distributed… <ul><li>Food security  is the ability to obtain sufficient, healthy food on a day-t...
Famines usually have political and  social roots <ul><li>Globally, widespread hunger arises when political instability, wa...
7-
7.2 Eating Right to Stay Healthy <ul><li>A good diet is essential to keep you healthy. </li></ul><ul><li>You need the righ...
A healthy diet includes the right nutrients <ul><li>Malnourishment  is a general term for nutritional imbalances caused by...
The Harvard food pyramid 7-
Overeating is a growing world problem <ul><li>Increasing world food supplies and low prices cause increasing overweight an...
7.3 The Foods We Eat <ul><li>Of the thousands of edible plants and animals in the world, only a few provide almost all our...
A boom in meat production brings costs and benefits <ul><li>Because of dramatic increases in corn and soy production, meat...
Meat is a good indicator of wealth  7-
Confined animal feeding operation (CAFO) 7-
Seafood is both wild and farmed <ul><li>Overharvesting and habitat destruction threaten most of the world’s wild fisheries...
Fish pins <ul><li>Net pens anchored in nearshore areas allow spread of diseases, escape of exotic species, and release of ...
Increased production comes with increased risks <ul><li>There are many environmental worries about this efficient producti...
7.4 Soil Is a Living Resource <ul><li>Soil is a marvelous substance, a living resource of astonishing complexity and frail...
What is soil? <ul><li>Soil is a complex mixture of six components: </li></ul><ul><ul><li>sand and gravel-mineral particles...
7-
Soil Horizons 7-
7.5 Ways We Use and Abuse Soil <ul><li>Agriculture both causes and suffers from environmental degradation. </li></ul><ul><...
Causes of Soil Erosion and Degradation 7-
Farming accelerates erosion <ul><li>Erosion is an important natural process, resulting in the redistribution of the produc...
Wind and water move soil <ul><li>Sheet erosion:  water flowing across a gently sloping, bare field removing a thin, unifor...
Wind and water are the main agents that move soil around.  7-
Wind can equal or exceed  water in erosive force <ul><li>In extreme conditions, windblown dunes encroach on useful land an...
7.6 Other Agricultural Resources <ul><li>Irrigation is necessary for high yields </li></ul><ul><ul><li>Agriculture account...
7.7 How We Have Managed to  Feed Billions <ul><li>In the developed countries, 95 percent of agricultural growth in the twe...
The green revolution has increased yields <ul><li>Most of this gain was accomplished by use of synthetic fertilizers along...
Genetic engineering could have benefits and costs <ul><li>Genetic engineering:  splicing a gene from one organism into the...
Is genetic engineering safe? <ul><li>The greatest danger is the ecological effects if these organisms spread into the nati...
7.8 Alternatives in Food and Farming <ul><li>Soil conservation is essential </li></ul><ul><ul><li>With careful husbandry, ...
Soil conservation is essential 7-
7.9 Consumer Choices Can Reshape Farming <ul><li>You can be a locavore </li></ul><ul><ul><li>Locavore:  a person who consu...
Practice Quiz <ul><li>1. What is Brazil’s Cerrado, and how is agriculture affecting it? </li></ul><ul><li>2. Explain how s...
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  • Chapt07 Lecture

    1. 1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 7 Lecture Outline
    2. 2. Learning Outcomes After studying this chapter, you should be able to answer the following questions: <ul><li>• How have global food production and population changed? </li></ul><ul><li>• How many people are chronically hungry, and why does hunger persist in a world of surpluses? </li></ul><ul><li>• What are some health risks of undernourishment, poor diet, and overeating? </li></ul><ul><li>• What are our primary food crops? </li></ul><ul><li>• Describe five components of soil. </li></ul><ul><li>• What was the green revolution? </li></ul><ul><li>• What are GMOs, and what traits are most commonly introduced with GMOs? </li></ul><ul><li>• Describe some environmental costs of farming, and ways we can minimize these costs. </li></ul>7-
    3. 3. We can’t solve problems by using the same kind of thinking we used when we created them. –Albert Einstein 7-
    4. 4. 7.1 Global Trends in Food and Nutrition <ul><li>Food production has been transformed from small-scale, diversified, family operations to expansive farms of thousands of hectares, growing one or two genetically modified crops, with abundant inputs of fuel and fertilizer, for a competitive global market. </li></ul>7-
    5. 5. Hunger around the world 7-
    6. 6. Food security is unevenly distributed <ul><li>Four decades ago, hunger was one of the world’s most prominent, persistent problems. </li></ul><ul><li>In 1960, nearly 60 percent of people in developing countries were chronically undernourished, and the world’s population was increasing by more than 2 percent every year. </li></ul><ul><li>Today, some conditions have changed dramatically; others have changed very little. </li></ul><ul><li>The world’s population has risen from 3 billion to over 6.5 billion, but food production has increased even faster. </li></ul>7-
    7. 7. Food security is unevenly distributed… <ul><li>Food security is the ability to obtain sufficient, healthy food on a day-to-day basis, is a combined problem of economic, environmental, and social conditions. </li></ul><ul><li>In wealthy countries such as the United States, millions lack a sufficient, healthy diet. </li></ul><ul><li>In the poorest countries, entire national economies can suffer from a severe drought, flood, or insect outbreak. </li></ul>7-
    8. 8. Famines usually have political and social roots <ul><li>Globally, widespread hunger arises when political instability, war, and conflict displace populations, removing villagers from their farms or making farming too dangerous to carry on. </li></ul><ul><li>Famines are large-scale food shortages, with widespread starvation, social disruption, and economic chaos. </li></ul>7-
    9. 9. 7-
    10. 10. 7.2 Eating Right to Stay Healthy <ul><li>A good diet is essential to keep you healthy. </li></ul><ul><li>You need the right nutrients, as well as enough calories for a productive and energetic lifestyle. </li></ul>7-
    11. 11. A healthy diet includes the right nutrients <ul><li>Malnourishment is a general term for nutritional imbalances caused by a lack of specific nutrients. </li></ul>7-
    12. 12. The Harvard food pyramid 7-
    13. 13. Overeating is a growing world problem <ul><li>Increasing world food supplies and low prices cause increasing overweight and obese populations. </li></ul><ul><li>In the U.S., and increasingly in Europe, China, and developing countries, highly processed foods rich in sugars and fats have become a large part of our diet. </li></ul><ul><li>Some 64 percent of adult Americans are overweight, up from 40 percent only a decade ago. About one-third of us are seriously overweight, or obese (generally considered to mean more than 20 percent over the ideal weight for a person’s height and sex. </li></ul>7-
    14. 14. 7.3 The Foods We Eat <ul><li>Of the thousands of edible plants and animals in the world, only a few provide almost all our food. </li></ul>7-
    15. 15. A boom in meat production brings costs and benefits <ul><li>Because of dramatic increases in corn and soy production, meat consumption has grown in both developed and developing countries. </li></ul><ul><li>Meat is a concentrated, high-value source of protein, iron, fats, and other nutrients that give us the energy to lead productive lives. </li></ul>7-
    16. 16. Meat is a good indicator of wealth 7-
    17. 17. Confined animal feeding operation (CAFO) 7-
    18. 18. Seafood is both wild and farmed <ul><li>Overharvesting and habitat destruction threaten most of the world’s wild fisheries. </li></ul><ul><li>The problem is too many boats using efficient but destructive technology to exploit a dwindling resource base. </li></ul><ul><li>Aquaculture is providing an increasing share of the world’s seafood. </li></ul>7-
    19. 19. Fish pins <ul><li>Net pens anchored in nearshore areas allow spread of diseases, escape of exotic species, and release of feces, uneaten food, antibiotics, and other pollutants into surrounding ecosystems. </li></ul>7-
    20. 20. Increased production comes with increased risks <ul><li>There are many environmental worries about this efficient production. </li></ul><ul><ul><li>Land conversion from pasture to soy and corn fields raises the rate of soil erosion. </li></ul></ul><ul><ul><li>Constant use of antibiotics raises the very real risk of antibiotic-resistant diseases. </li></ul></ul>7-
    21. 21. 7.4 Soil Is a Living Resource <ul><li>Soil is a marvelous substance, a living resource of astonishing complexity and frailty. </li></ul><ul><li>It is a complex mixture of: </li></ul><ul><ul><li>mineral grains weathered from rocks, </li></ul></ul><ul><ul><li>partially decomposed organic molecules, and </li></ul></ul><ul><ul><li>a host of living organisms. </li></ul></ul><ul><li>Soil can be considered a living ecosystem by itself. </li></ul>7-
    22. 22. What is soil? <ul><li>Soil is a complex mixture of six components: </li></ul><ul><ul><li>sand and gravel-mineral particles from bedrock, either in place or moved from elsewhere, as in wind-blown sand. </li></ul></ul><ul><ul><li>silts and clays -extremely small mineral particles; many clays are sticky and hold water because of their flat surfaces and ionic charges; others give red color to soil. </li></ul></ul><ul><ul><li>dead organic material-decaying plant matter stores nutrients and gives soils a black or brown color. </li></ul></ul><ul><ul><li>soil fauna and flora -living organisms, including soil bacteria, worms, fungi, roots of plants, and insects, recycle organic compounds and nutrients. </li></ul></ul><ul><ul><li>water -moisture from rainfall or groundwater, essential for soil fauna and plants. </li></ul></ul><ul><ul><li>air -tiny pockets of air help soil bacteria and other organisms survive. </li></ul></ul>7-
    23. 23. 7-
    24. 24. Soil Horizons 7-
    25. 25. 7.5 Ways We Use and Abuse Soil <ul><li>Agriculture both causes and suffers from environmental degradation. </li></ul><ul><li>The causes of this extreme degradation vary: </li></ul><ul><ul><li>In Ethiopia, it is water erosion. </li></ul></ul><ul><ul><li>In Somalia, it is wind; and in Uzbekistan, salt and toxic chemicals are responsible. </li></ul></ul><ul><ul><li>In Sweden and Finland, fallout from the Chernobyl nuclear reaction explosion has contaminated large amounts of grazing land and farmland. </li></ul></ul>7-
    26. 26. Causes of Soil Erosion and Degradation 7-
    27. 27. Farming accelerates erosion <ul><li>Erosion is an important natural process, resulting in the redistribution of the products of geologic weathering, and it is part of both soil formation and soil loss. </li></ul><ul><li>Where erosion has worn down mountains and spread soil over the plains or deposited rich alluvial silt in river bottoms, we farm it. </li></ul>7-
    28. 28. Wind and water move soil <ul><li>Sheet erosion: water flowing across a gently sloping, bare field removing a thin, uniform layer of soil. </li></ul><ul><li>Rill erosion: when little rivulets of running water gather together and cut small channels in the soil. </li></ul><ul><li>Gully erosion: if rills enlarge to form bigger channels or ravines that are too large to be removed by normal tillage operations. </li></ul><ul><li>Desertification: conversion of productive land to desert. </li></ul>7-
    29. 29. Wind and water are the main agents that move soil around. 7-
    30. 30. Wind can equal or exceed water in erosive force <ul><li>In extreme conditions, windblown dunes encroach on useful land and cover roads and buildings. </li></ul><ul><li>Over the past 30 years, China has lost 93,000 km2 (about the size of Indiana) to desertification. </li></ul><ul><li>Advancing dunes from the Gobi desert are now only 160 km (100 mi) from Beijing. </li></ul>7-
    31. 31. 7.6 Other Agricultural Resources <ul><li>Irrigation is necessary for high yields </li></ul><ul><ul><li>Agriculture accounts for the largest single share of global water use. </li></ul></ul><ul><ul><li>Salinization: mineral salts accumulate in the soil due to evaporating water from irrigation. </li></ul></ul><ul><li>Fertilizer boosts production </li></ul><ul><ul><li>Much of the doubling in worldwide crop production since 1950 has come from increased inorganic fertilizer use. </li></ul></ul><ul><li>Modern agriculture runs on oil </li></ul><ul><li>Pest control saves crops </li></ul>7-
    32. 32. 7.7 How We Have Managed to Feed Billions <ul><li>In the developed countries, 95 percent of agricultural growth in the twentieth century came from improved crop varieties ( the green revolution) or increased fertilization, irrigation, and pesticide use, rather than from bringing new land into production. </li></ul>7-
    33. 33. The green revolution has increased yields <ul><li>Most of this gain was accomplished by use of synthetic fertilizers along with conventional plant breeding: geneticists laboriously hand-pollinating plants and looking for desired characteristics in the progeny. </li></ul><ul><li>Starting about 50 years ago, agricultural research stations began to breed tropical wheat and rice varieties that would provide food for growing populations in developing countries. </li></ul>7-
    34. 34. Genetic engineering could have benefits and costs <ul><li>Genetic engineering: splicing a gene from one organism into the chromosome of another. </li></ul><ul><li>Genetically modified organisms (GMOs ): organisms with entirely new genes, and even new organisms, often called “transgenic” organisms. </li></ul>7-
    35. 35. Is genetic engineering safe? <ul><li>The greatest danger is the ecological effects if these organisms spread into the native populations. </li></ul><ul><li>There are social and economic implications of GMOs. Will they help feed the world, or will they lead to a greater consolidation of corporate power and economic disparity? </li></ul><ul><li>Are GMO’s required if we hope to reduce malnutrition and feed eight billion people in 50 years. </li></ul>7-
    36. 36. 7.8 Alternatives in Food and Farming <ul><li>Soil conservation is essential </li></ul><ul><ul><li>With careful husbandry, soil is a renewable resource that can be replenished and renewed indefinitely. </li></ul></ul><ul><ul><li>Water runoff can be reduced by grass strips in waterways and by contour plowing, plowing across the hill rather than up and down. </li></ul></ul><ul><ul><li>Terracing is shaping the land to create level shelves of earth to hold water and soil. </li></ul></ul>7-
    37. 37. Soil conservation is essential 7-
    38. 38. 7.9 Consumer Choices Can Reshape Farming <ul><li>You can be a locavore </li></ul><ul><ul><li>Locavore: a person who consumes locally produced food. </li></ul></ul><ul><li>You can eat low on the food chain </li></ul><ul><ul><li>Since there is less energy involved in producing food from plants, you can reduce your impact by eating more grains, vegetables, and dairy and a little less meat. </li></ul></ul><ul><li>You can eat organic, low-input foods </li></ul><ul><ul><li>If you buy organic food, you are supporting farmers who use no pesticides or artificial fertilizers. </li></ul></ul>7-
    39. 39. Practice Quiz <ul><li>1. What is Brazil’s Cerrado, and how is agriculture affecting it? </li></ul><ul><li>2. Explain how soybeans grown in Brazil are improving diets in China. </li></ul><ul><li>3. What does it mean to be chronically undernourished? How many people in the world currently suffer from this condition? </li></ul><ul><li>4. Why do nutritionists worry about food security? Who is most likely to suffer from food insecurity? </li></ul><ul><li>5. Describe the conditions that constitute a famine. Why does Amartya Sen say that famines are caused more by politics and </li></ul><ul><li>economics than by natural disasters? </li></ul><ul><li>6. Define malnutrition and obesity. How many Americans are now considered obese? </li></ul><ul><li>7. What three crops provide most human caloric intake? </li></ul>7-

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