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Chapter 12 Food, Soil Conservation, and Pest Management.

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1 Chapter 12 Food, Soil Conservation, and Pest Management

2 FOOD SECURITY AND NUTRITION  Global food production has stayed ahead of population growth. However: 1/6 of people in developing countries cannot grow or buy the food they need. 1/6 of people in developing countries cannot grow or buy the food they need.  The root cause of hunger and malnutrition is poverty.  Food security - every person in a given area has access to enough nutritious food to have an active and healthy life. macronutrients (protein, carbohydrates, and fats). macronutrients (protein, carbohydrates, and fats). micronutrients (vitamins such as A,C, and E). micronutrients (vitamins such as A,C, and E).

3 FOOD SECURITY AND NUTRITION  1/3 of people have a deficiency of one or more vitamins and minerals vitamin A vitamin A iodine iodine goiter - enlargement of thyroid gland goiter - enlargement of thyroid gland iron iron Figure 13-2

4 War and the Environment  Starving children collecting ants to eat in famine-stricken Sudan, Africa which has been involved in civil war since 1983. Figure 13-3

5 Solutions: Reducing Childhood Deaths from Hunger and Malnutrition  There are several ways to reduce childhood deaths from nutrition-related causes: Immunize children. Immunize children. Encourage breast-feeding. Encourage breast-feeding. Prevent dehydration from diarrhea. Prevent dehydration from diarrhea. Prevent blindness from vitamin A deficiency. Prevent blindness from vitamin A deficiency. Provide family planning. Provide family planning. Increase education for women. Increase education for women.

6 Overnutrition: Eating Too Much  Overnutrition and lack of exercise can lead to reduced life quality, poor health, and premature death.  A 2005 Boston University study found that about 60% of American adults are overweight and 33% are obese Americans spend $42 billion per year trying to lose weight. Americans spend $42 billion per year trying to lose weight.  $24 billion per year is needed to eliminate world hunger.

7 FOOD PRODUCTION  Food production from croplands, rangelands, ocean fisheries, and aquaculture has increased dramatically.  Wheat, rice, and corn provide more than half of the world’s consumed calories. Fish and shellfish are an important source of food for about 1 billion people mostly in Asia and in coastal areas of developing countries. Fish and shellfish are an important source of food for about 1 billion people mostly in Asia and in coastal areas of developing countries.

8 Industrial Food Production: High Input Monocultures  About 80% of the world’s food supply is produced by industrialized agriculture. Uses large amounts of fossil fuel energy, water, commercial fertilizers, and pesticides to produce monocultures. Uses large amounts of fossil fuel energy, water, commercial fertilizers, and pesticides to produce monocultures. Greenhouses are increasingly being used. Greenhouses are increasingly being used. Plantations are being used in tropics for cash crops such as coffee, sugarcane, bananas. Plantations are being used in tropics for cash crops such as coffee, sugarcane, bananas.

9 Fig. 13-4, p. 275 Plantation agriculture Shifting cultivation Industrialized agriculture No agriculture Intensive traditional ag. Nomadic herding

10 Industrial Food Production: High Input Monocultures  Livestock production in developed countries is industrialized: Feedlots are used to fatten up cattle before slaughter. Feedlots are used to fatten up cattle before slaughter. Most pigs and chickens live in densely populated pens or cages. Most pigs and chickens live in densely populated pens or cages. Most livestock are fed grain grown on cropland. Most livestock are fed grain grown on cropland. Systems use a lot of energy and water and produce huge amounts of animal waste. Systems use a lot of energy and water and produce huge amounts of animal waste.

11 Case Study: Industrialized Food Production in the United States  The U.S. uses industrialized agriculture to produce about 17% of the world’s grain. Relies on cheap energy to run machinery, process food, produce commercial fertilizer and pesticides. Relies on cheap energy to run machinery, process food, produce commercial fertilizer and pesticides.  About 10 units of nonrenewable fossil fuel energy are needed to put 1 unit of food energy on the table.

12 Case Study: Industrialized Food Production in the United States  Industrialized agriculture uses about 17% of all commercial energy in the U.S. and food travels an average 2,400 kilometers from farm to plate. Figure 13-7

13 Traditional Agriculture: Low Input Polyculture  Many farmers in developing countries use low- input agriculture to grow a variety of crops on each plot of land (interplanting) through: Polyvarietal cultivation: planting several genetic varieties. Polyvarietal cultivation: planting several genetic varieties. Intercropping: two or more different crops grown at the same time in a plot. Intercropping: two or more different crops grown at the same time in a plot. Agroforestry: crops and trees are grown together. Agroforestry: crops and trees are grown together. Polyculture: different plants are planted together. Polyculture: different plants are planted together.

14 EOS Winery in Paso Robles  EOS Estate Winery in Paso Robles is undertaking a massive solar project that will put it on the map as the largest winery in the Paso Robles Wine Country to convert entirely to solar power.

15 Traditional Agriculture: Low Input Polyculture  Research has shown that, on average, low input polyculture produces higher yields than high-input monoculture. Figure 13-8

16 SOIL EROSION AND DEGRADATION  Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded sediment. Sheet erosion: surface water or wind peel off thin layers of soil. Sheet erosion: surface water or wind peel off thin layers of soil. Rill erosion: fast-flowing little rivulets of surface water make small channels. Rill erosion: fast-flowing little rivulets of surface water make small channels. Gully erosion: fast-flowing water join together to cut wider and deeper ditches or gullies. Gully erosion: fast-flowing water join together to cut wider and deeper ditches or gullies.

17 SOIL EROSION AND DEGRADATION  Soil erosion is the movement of soil components, especially surface litter and topsoil, by wind or water.  Soil erosion increases through activities such as farming, logging, construction, overgrazing, and off-road vehicles. Figure 13-9

18 Global Outlook: Soil Erosion  Soil is eroding faster than it is forming on more than one-third of the world’s cropland. Figure 13-10

19 Case Study: Soil Erosion in the U.S. – Some Hopeful Signs  Soil erodes faster than it forms on most U.S. cropland, but since 1985, has been cut by about 40%. 1985 Food Security Act (Farm Act): farmers receive a subsidy for taking highly erodible land out of production and replanting it with soil saving plants for 10-15 years. 1985 Food Security Act (Farm Act): farmers receive a subsidy for taking highly erodible land out of production and replanting it with soil saving plants for 10-15 years.

20 Desertification: Degrading Drylands  About one-third of the world’s land has lost some of its productivity because of drought and human activities that reduce or degrade topsoil. Figure 13-12

21 Salinization and Waterlogging  Repeated irrigation can reduce crop yields by causing salt buildup in the soil and waterlogging of crop plants. Figure 13-13

22 Fig. 13-15, p. 281 Cleanup Prevention Soil Salinization Solutions Reduce irrigation Switch to salt- tolerant crops (such as barley, cotton, sugarbeet) Flush soil (expensive and wastes water) Stop growing crops for 2–5 years Install underground drainage systems (expensive)

23 Salinization and Waterlogging of Soils: A Downside of Irrigation  Example of high evaporation, poor drainage, and severe salinization.  White alkaline salts have displaced crops. Example: west side of our Valley Example: west side of our Valley Figure 13-14

24 SUSTAINABLE AGRICULTURE THROUGH SOIL CONSERVATION  Modern farm machinery can plant crops without disturbing soil (no-till and minimum tillage. Conservation-tillage farming: Conservation-tillage farming: Increases crop yield.Increases crop yield. Raises soil carbon content.Raises soil carbon content. Lowers water use.Lowers water use. Lowers pesticides.Lowers pesticides. Uses less tractor fuel.Uses less tractor fuel.

25 SUSTAINABLE AGRICULTURE THROUGH SOIL CONSERVATION  Terracing, contour planting, strip cropping, alley cropping, and windbreaks can reduce soil erosion. Figure 13-16

26 SUSTAINABLE AGRICULTURE THROUGH SOIL CONSERVATION  Fertilizers can help restore soil nutrients, but runoff of inorganic fertilizers can cause water pollution. Organic fertilizers: from plant and animal (fresh, manure, or compost) materials. Organic fertilizers: from plant and animal (fresh, manure, or compost) materials. Commercial inorganic fertilizers: Active ingredients contain nitrogen, phosphorous, and potassium and other trace nutrients. Commercial inorganic fertilizers: Active ingredients contain nitrogen, phosphorous, and potassium and other trace nutrients.

27 THE GREEN REVOLUTION AND ITS ENVIRONMENTAL IMPACT  Since 1950, high-input agriculture has produced more crops per unit of land.  In 1967, fast growing dwarf varieties of rice and wheat were developed for tropics and subtropics. Figure 13-17

28 THE GREEN REVOLUTION AND ITS ENVIRONMENTAL IMPACT  Lack of water, high costs for small farmers, and physical limits to increasing crop yields hinder expansion of the green revolution.  Since 1978 the amount of irrigated land per person has declined due to: Depletion of underground water supplies. Depletion of underground water supplies. Inefficient irrigation methods. Inefficient irrigation methods. Salt build-up. Salt build-up. Cost of irrigating crops. Cost of irrigating crops.

29 THE GREEN REVOLUTION AND ITS ENVIRONMENTAL IMPACT  Modern agriculture has a greater harmful environmental impact than any human activity.  Loss of a variety of genetically different crop and livestock strains might limit raw material needed for future green and gene revolutions. In the U.S., 97% of the food plant varieties available in the 1940 no longer exist in large quantities. In the U.S., 97% of the food plant varieties available in the 1940 no longer exist in large quantities.

30 Fig. 13-18, p. 285 Biodiversity LossSoil Water Air PollutionHuman Health Loss and degradation of grasslands, forests, and wetlands Erosion Water waste Greenhouse gas emissions from fossil fuel use Nitrates in drinking water Loss of fertility Aquifer depletion Pesticide residues in drinking water, food, and air Salinization Increased runoff and flooding from cleared land Other air pollutants from fossil fuel use Fish kills from pesticide runoff Waterlogging Sediment pollution from erosion Greenhouse gas emissions of nitrous oxide from use of inorganic fertilizers Contamination of drinking and swimming water with disease organisms from livestock wastes Desertification Killing wild predators to protect livestock Fish kills from pesticide runoff Surface and groundwater pollution from pesticides and fertilizers Belching of the greenhouse gas methane by cattle Loss of genetic diversity of wild crop strains replaced by monoculture strains Bacterial contamination of meat Overfertilization of lakes and rivers from runoff of fertilizers, livestock wastes, and food processing wastes Pollution from pesticide sprays

31 THE GENE REVOLUTION  To increase crop yields, we can mix the genes of similar types of organisms and mix the genes of different organisms. Artificial selection has been used for centuries to develop genetically improved varieties of crops. Artificial selection has been used for centuries to develop genetically improved varieties of crops. Genetic engineering develops improved strains at an exponential pace compared to artificial selection. Genetic engineering develops improved strains at an exponential pace compared to artificial selection.  Controversy has arisen over the use of genetically modified food (GMF).

32 Mixing Genes  Genetic engineering involves splicing a gene from one species and transplanting the DNA into another species. Figure 13-19

33 THE GENE REVOLUTION  The winged bean, a GMF, could be grown to help reduce malnutrition and the use of large amounts of inorganic fertilizers. Figure 13-20

34 THE GENE REVOLUTION  Controversy has arisen over the use of genetically modified food (GMF). Critics fear that we know too little about the long- term potential harm to human and ecosystem health. Critics fear that we know too little about the long- term potential harm to human and ecosystem health.  There is controversy over legal ownership of genetically modified crop varieties and whether GMFs should be labeled.

35 PRODUCING MORE MEAT  About half of the world’s meat is produced by livestock grazing on grass.  The other half is produced under factory-like conditions (feedlots). Densely packed livestock are fed grain or fish meal. Densely packed livestock are fed grain or fish meal.  Eating more chicken and farm-raised fish and less beef and pork reduces harmful environmental impacts of meat production.

36 Fig. 13-21, p. 289 Trade-Offs Animal Feedlots AdvantagesDisadvantages Increased meat production Need large inputs of grain, fish meal, water, and fossil fuels Higher profits Concentrate animal wastes that can pollute water Less land use Reduced overgrazing Reduced soil erosion Antibiotics can increase genetic resistance to microbes in humans Help protect biodiversity

37 How Many People can the World Support? Food Production and Population  The number of people the world can support depends mostly on their per capita consumption of grain and meat and how many children couples have. Research has shown that those living very low on the food chain or very high on the food chain do not live as long as those that live somewhere in between. Research has shown that those living very low on the food chain or very high on the food chain do not live as long as those that live somewhere in between.

38 PRODUCING MORE MEAT  Efficiency of converting grain into animal protein. Figure 13-22

39 CATCHING AND RAISING MORE FISH AND SHELLFISH  After spectacular increases, the world’s total and per capita marine and freshwater fish and shellfish catches have leveled off. Figure 13-23

40 CATCHING AND RAISING MORE FISH AND SHELLFISH  Government subsidies given to the fishing industry are a major cause of overfishing. Global fishing industry spends about $25 billion per year more than its catch is worth. Global fishing industry spends about $25 billion per year more than its catch is worth. Without subsidies many fishing fleets would have to go out of business. Without subsidies many fishing fleets would have to go out of business. Subsidies allow excess fishing with some keeping their jobs longer with making less money. Subsidies allow excess fishing with some keeping their jobs longer with making less money.

41 Aquaculture: Aquatic Feedlots  Raising large numbers of fish and shellfish in ponds and cages is world’s fastest growing type of food production.  Fish farming involves cultivating fish in a controlled environment and harvesting them in captivity.  Fish ranching involves holding anadromous species that live part of their lives in freshwater and part in saltwater. Fish are held for the first few years, released, and then harvested when they return to spawn. Fish are held for the first few years, released, and then harvested when they return to spawn.

42 Fig. 13-24, p. 292 Trade-Offs Aquaculture AdvantagesDisadvantages High efficiencyNeeds large inputs of land, feed, and water High yield in small volume of water Large waste output Destroys mangrove forests and estuaries Can reduce overharvesting of conventional fisheries Uses grain to feed some species Low fuel use Dense populations vulnerable to disease Tanks too contaminated to use after about 5 years High profits Profits not tied to price of oil

43 Fig. 13-25, p. 293 Solutions More Sustainable Aquaculture Use less fishmeal feed to reduce depletion of other fish Improve management of aquaculture wastes Reduce escape of aquaculture species into the wild Restrict location of fish farms to reduce loss of mangrove forests and estuaries Farm some aquaculture species in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean Certify sustainable forms of aquaculture

44 SOLUTIONS: MOVING TOWARD GLOBAL FOOD SECURITY  People in urban areas could save money by growing more of their food. Urban gardens provide about 15% of the world’s food supply. Urban gardens provide about 15% of the world’s food supply.  Up to 90% of the world’s food is wasted. Figure 13-26

45 Government Policies and Food Production  Governments use three main approaches to influence food production: Control prices to keep prices artificially low. Control prices to keep prices artificially low. Provide subsidies to keep farmers in business. Provide subsidies to keep farmers in business. Let the marketplace decide rather that implementing price controls. Let the marketplace decide rather that implementing price controls.

46 Solutions: Steps Toward More Sustainable Food Production  We can increase food security by slowing populations growth, sharply reducing poverty, and slowing environmental degradation of the world’s soils and croplands.

47 PROTECTING FOOD RESOURCES: PEST MANAGEMENT  Organisms found in nature (such as spiders) control populations of most pest species as part of the earth’s free ecological services. Figure 13-27

48 PROTECTING FOOD RESOURCES: PEST MANAGEMENT  We use chemicals to repel or kill pest organisms as plants have done for millions of years.  Chemists have developed hundreds of chemicals (pesticides) that can kill or repel pests. Pesticides vary in their persistence. Pesticides vary in their persistence. Each year > 250,000 people in the U.S. become ill from household pesticides. Each year > 250,000 people in the U.S. become ill from household pesticides.

49 PROTECTING FOOD RESOURCES: PEST MANAGEMENT  Advantages and disadvantages of conventional chemical pesticides. Figure 13-28

50 What is a “Pest”?  Something competes with us for food or other resources Ex: plants, insects, rodents, etc. Ex: plants, insects, rodents, etc.  Most insects are not pests! *99% of plants, animals, and microbes benefit agriculture and our economy *99% of plants, animals, and microbes benefit agriculture and our economy  In diverse ecosystems, “pests” are kept at low levels by their natural enemies Agriculture does not normally produce a diverse ecosystem Agriculture does not normally produce a diverse ecosystem

51 What is a “Pest”?  Pesticides-(Carson called them biocides) kill undesirable organisms kill undesirable organisms Rodenticides, Fungicides, Insecticides, HerbicidesRodenticides, Fungicides, Insecticides, Herbicides

52 The Ideal Pesticide has these qualities: Kills only target pest. Kills only target pest. Does not cause genetic resistance in the target organism. Does not cause genetic resistance in the target organism. Disappears or breaks down into harmless chemicals after doing its job. Disappears or breaks down into harmless chemicals after doing its job. Be more cost-effective than doing nothing. Be more cost-effective than doing nothing.  *There is no “ideal” pesticide- few even come close

53 First Generation Pesticides  Naturally derived chemicals from plants or animals or naturally occurring minerals Nicotine sulfate Nicotine sulfate Pyrethrum Pyrethrum Red pepper (repels ants) Red pepper (repels ants) Garlic Garlic Lemon oil (repels fleas, mosquitos, flies,etc) Lemon oil (repels fleas, mosquitos, flies,etc) Sulfur Sulfur Arsenic Arsenic Lead Lead

54 Second Generation Pesticides Synthetic or man-made pesticides 1874- DDT invented 1939- DDT discovered to be an insecticide 30% of all pesticides used in the US are for houses, gardens, lawns, parcels, swimming, pools, and golf courses. 1991- US farmers 84% of all pesticides were herbicides 14% insecticides 2% fungicides Corn, wheat, cotton, and soybeans receive most. 1994- Each US farmer fed and clothed 140 people (105 at home; 35 abroad) 0.3% of world’s farm labor, produce 25% of world’s food and ½ of world grain exports

55 Problems with pesticides  Resistance- genetic, alters population  Mobility and biological amplification Very little of pesticides applied reach the target pest Very little of pesticides applied reach the target pest 2% max in aerial spraying2% max in aerial spraying Amplified in the food chain- DDT Amplified in the food chain- DDT Page 299- What Goes Around Can Come AroundPage 299- What Goes Around Can Come Around  Threats to wildlife Honey bees- organophosphate Honey bees- organophosphate Fish- herbicides Fish- herbicides  Human Health Worker- Applicators- work with undiluted product Worker- Applicators- work with undiluted product

56 Superpests  Superpests are resistant to pesticides.  Superpests like the silver whitefly (left) challenge farmers as they cause > $200 million per year in U.S. crop losses. Figure 13-29

57 Other Ways to Control Pests  There are cultivation, biological, and ecological alternatives to conventional chemical pesticides. Fool the pest through cultivation practices. Fool the pest through cultivation practices. Provide homes for the pest enemies. Provide homes for the pest enemies. Implant genetic resistance. Implant genetic resistance. Bring in natural enemies. Bring in natural enemies. Use pheromones to lure pests into traps. Use pheromones to lure pests into traps. Use hormones to disrupt life cycles. Use hormones to disrupt life cycles.

58 Other Ways to Control Pests  Biological pest control: Wasp parasitizing a gypsy moth caterpillar. Figure 13-31

59 Other Ways to Control Pests  Genetic engineering can be used to develop pest and disease resistant crop strains.  Both tomato plants were exposed to destructive caterpillars. The genetically altered plant (right) shows little damage. Figure 13-32

60 Integrated Pest Management  IPM uses a combination of the following along with chemical to control pests (keep them below the economic threshold): Monitoring is essential Monitoring is essential Cultural control Cultural control Natural enemies Natural enemies Bio pesticides Bio pesticides Genetic engineering Genetic engineering Pheromones, sterile males, juvenile hormones, radiation Pheromones, sterile males, juvenile hormones, radiation

61 Integrated Pest Management  Economic Threshold-The level at which the pest does more damage than the cost of the control  University of California researchers have established economic thresholds for the State’s major crops and their pests Requires weekly or biweekly monitoring so the grower will know when it is time to spray Requires weekly or biweekly monitoring so the grower will know when it is time to spray

62 Individuals Matter: Rachel Carson  Wrote Silent Spring which introduced the U.S. to the dangers of the pesticide DDT and related compounds to the environment. Figure 13-A

63 Pesticide Protection Laws in the U.S.  Government regulation has banned a number of harmful pesticides but some scientists call for strengthening pesticide laws. The Environmental Protection Agency (EPA), the Department of Agriculture (USDA), and the Food and Drug Administration (FDA) regulate the sales of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The Environmental Protection Agency (EPA), the Department of Agriculture (USDA), and the Food and Drug Administration (FDA) regulate the sales of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides. The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides.

64 Fig. 13-30, p. 299 What Can You Do? Reducing Exposure to Pesticides Grow some of your food using organic methods. Buy organic food. Wash and scrub all fresh fruits, vegetables, and wild foods you pick. Eat less or no meat. Trim the fat from meat.

65 SOLUTIONS: SUSTAINABLE AGRICULTURE  Three main ways to reduce hunger and malnutrition and the harmful effects of agriculture: Slow population growth. Slow population growth. Sharply reduce poverty. Sharply reduce poverty. Develop and phase in systems of more sustainable, low input agriculture over the next few decades. Develop and phase in systems of more sustainable, low input agriculture over the next few decades.

66 Sustainable Agriculture Figure 13-34

67 Problems that need to be solved:  Organic farming requires natural controls for all pests in a crop We do not currently have this for all crops We do not currently have this for all crops  Organic farming is labor intensive, expensive in developed countries  Some damage will occur In order for natural enemies to exist, some pests must exist In order for natural enemies to exist, some pests must exist  Currently organic farmers make a profit because they charge more in specialty markets

68 Solutions: Making the Transition to More Sustainable Agriculture  More research, demonstration projects, government subsidies, and training can promote more sustainable organic agriculture. Figure 13-35


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