chapter 13 food, soil conservation, and pest management

Chapter 13Chapter 13

Food, Soil Conservation, Food, Soil Conservation, and Pest Managementand Pest Management

Chapter Overview QuestionsChapter Overview Questions

What is food security?What is food security? How serious are malnutrition and How serious are malnutrition and

overnutrition?overnutrition? How is the worldHow is the world’’s food produced?s food produced? How are soils being degraded and eroded, How are soils being degraded and eroded,

and what can be done to reduce these and what can be done to reduce these losses?losses?

What are the advantages and disadvantages What are the advantages and disadvantages of using the green revolution to produce of using the green revolution to produce food?food?

Chapter Overview Questions (contChapter Overview Questions (cont’’d)d)

What are the environmental effects of What are the environmental effects of producing food?producing food?

What are the advantages and disadvantages What are the advantages and disadvantages of using genetic engineering to produce of using genetic engineering to produce food?food?

How can we produce more meat, fish, and How can we produce more meat, fish, and shellfish?shellfish?

How can we protect food resources from How can we protect food resources from pests?pests?

Chapter Overview Questions (contChapter Overview Questions (cont’’d)d)

How do government policies affect food How do government policies affect food production and food security?production and food security?

How can we produce food more sustainably?How can we produce food more sustainably?

Updates OnlineUpdates Online

The latest references for topics covered in this section can be found at The latest references for topics covered in this section can be found at the book companion website. Log in to the bookthe book companion website. Log in to the book’’s e-resources page at s e-resources page at www.thomsonedu.com to access InfoTrac articles. www.thomsonedu.com to access InfoTrac articles.

InfoTrac: A renewable economy as a global ethic. InfoTrac: A renewable economy as a global ethic. Michael Lerner. Michael Lerner. The American ProspectThe American Prospect, April 2006 v17 , April 2006 v17 i4 pA30(2).i4 pA30(2).

InfoTrac: Appetite for destruction. Kathleen McGowam. InfoTrac: Appetite for destruction. Kathleen McGowam. AudubonAudubon, July-August 2006 v108 i4 p70(2)., July-August 2006 v108 i4 p70(2).

InfoTrac: Boom times for protein. Lester R. Brown. InfoTrac: Boom times for protein. Lester R. Brown. USA USA TodayToday (Magazine) July 2006 v135 i2734 p59(1). (Magazine) July 2006 v135 i2734 p59(1).

Union of Concerned Scientists: Genetic EngineeringUnion of Concerned Scientists: Genetic Engineering USDA: Fueling the Green RevolutionUSDA: Fueling the Green Revolution

Core Case Study: Golden Rice -Core Case Study: Golden Rice -Grains of Hope or an Illusion?Grains of Hope or an Illusion?

Golden rice is a new Golden rice is a new genetically genetically engineered strain of engineered strain of rice containing beta-rice containing beta-carotene.carotene.

Can inexpensively Can inexpensively supply vitamin A to supply vitamin A to malnourished.malnourished.

Figure 13-1Figure 13-1

Core Case Study: Golden Rice -Core Case Study: Golden Rice -Grains of Hope or an Illusion?Grains of Hope or an Illusion?

Critics contend that Critics contend that there are quicker and there are quicker and cheaper ways to cheaper ways to supply vitamin A.supply vitamin A.

Scientist call for Scientist call for more evidence that more evidence that the beta-carotene will the beta-carotene will be converted to be converted to vitamin A by the vitamin A by the body.body.


FOOD SECURITY AND NUTRITIONFOOD SECURITY AND NUTRITION

Global food production has stayed ahead of Global food production has stayed ahead of population growth. However:population growth. However: One of six people in developing countries cannot One of six people in developing countries cannot

grow or buy the food they need.grow or buy the food they need. Others cannot meet their basic energy needs Others cannot meet their basic energy needs

(undernutrition / hunger) or protein and key (undernutrition / hunger) or protein and key nutrients (malnutrition).nutrients (malnutrition).


The root cause of hunger and malnutrition is The root cause of hunger and malnutrition is poverty.poverty.

Food securityFood security means that every person in a means that every person in a given area has daily access to enough given area has daily access to enough nutritious food to have an active and healthy nutritious food to have an active and healthy life.life. Need large amounts of Need large amounts of macronutrientsmacronutrients (protein, (protein,

carbohydrates, and fats).carbohydrates, and fats). Need smaller amounts of Need smaller amounts of micronutrientsmicronutrients

(vitamins such as A,C, and E).(vitamins such as A,C, and E).


One in three people One in three people has a deficiency of has a deficiency of one or more vitamins one or more vitamins and minerals, and minerals, especially vitamin A, especially vitamin A, iodine (causes goiter iodine (causes goiter - enlargement of - enlargement of thyroid gland), and thyroid gland), and iron. iron.


War and the EnvironmentWar and the Environment

Starving children Starving children collecting ants to eat collecting ants to eat in famine-stricken in famine-stricken Sudan, Africa which Sudan, Africa which has been involved in has been involved in civil war since 1983.civil war since 1983.


Solutions: Reducing Childhood Solutions: Reducing Childhood Deaths from Hunger and MalnutritionDeaths from Hunger and Malnutrition

There are several ways to reduce childhood There are several ways to reduce childhood deaths from nutrition-related causes: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.

Overnutrition: Eating Too MuchOvernutrition: Eating Too Much

Overnutrition and lack of exercise can lead to Overnutrition and lack of exercise can lead to reduced life quality, poor health, and reduced life quality, poor health, and premature death.premature death.

A 2005 Boston University study found that A 2005 Boston University study found that about 60% of American adults are overweight about 60% of American adults are overweight and 33% are obese (totaling 93%).and 33% are obese (totaling 93%).

Americans spend $42 billion per year trying Americans spend $42 billion per year trying to lose weight.to lose weight.

$24 billion per year is needed to eliminate $24 billion per year is needed to eliminate world hunger.world hunger.

FOOD PRODUCTIONFOOD PRODUCTION

Food production from croplands, rangelands, Food production from croplands, rangelands, ocean fisheries, and aquaculture has ocean fisheries, and aquaculture has increased dramatically.increased dramatically.

Wheat, rice, and corn provide more than half Wheat, rice, and corn provide more than half of the worldof the world’’s consumed calories.s consumed calories. Fish and shellfish are an important source of food Fish and shellfish are an important source of food

for about 1 billion people mostly in Asia and in for about 1 billion people mostly in Asia and in coastal areas of developing countries.coastal areas of developing countries.

Animation: Land UseAnimation: Land Use

PLAYANIMATION

Industrial Food Production: Industrial Food Production: High Input MonoculturesHigh Input Monocultures

About 80% of the worldAbout 80% of the world’’s food supply is s food supply is produced by industrialized agriculture.produced by industrialized agriculture. Uses large amounts of fossil fuel energy, water, Uses large amounts of fossil fuel energy, water,

commercial fertilizers, and pesticides to produce commercial fertilizers, and pesticides to produce monocultures.monocultures.

Greenhouses are increasingly being used.Greenhouses are increasingly being used. Plantations are being used in tropics for cash Plantations are being used in tropics for cash

crops such as coffee, sugarcane, bananas.crops such as coffee, sugarcane, bananas.

Fig. 13-4, p. 275

Plantation agriculture

Shifting cultivation

Industrialized agriculture

No agriculture

Intensive traditional ag.

Nomadic herding

FOOD PRODUCTIONFOOD PRODUCTION

Satellite images of massive and rapid Satellite images of massive and rapid development of greenhouse food production development of greenhouse food production in Spain from 1974 (left) to 2000 (right).in Spain from 1974 (left) to 2000 (right).


Industrial Food Production: Industrial Food Production: High Input MonoculturesHigh Input Monocultures

Livestock production in developed countries Livestock production in developed countries is industrialized:is industrialized: Feedlots are used to fatten up cattle before Feedlots are used to fatten up cattle before

slaughter.slaughter. Most pigs and chickens live in densely populated Most pigs and chickens live in densely populated

pens or cages.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 Systems use a lot of energy and water and

produce huge amounts of animal waste.produce huge amounts of animal waste.

Fig. 13-6, p. 276

Natural Capital

Croplands

• Help maintain water flow and soil infiltration • Food crops

• Provide partial erosion protection• Fiber crops

• Can build soil organic matter

• Crop genetic resources• Store atmospheric carbon

• Provide wildlife habitat for some species • Jobs

Ecological Services

Economic Services

Case Study: Industrialized Food Case Study: Industrialized Food Production in the United StatesProduction in the United States

The U.S. uses industrialized agriculture to The U.S. uses industrialized agriculture to produce about 17% of the worldproduce about 17% of the world’’s grain.s grain. Relies on cheap energy to run machinery, Relies on cheap energy to run machinery,

process food, produce commercial fertilizer and process food, produce commercial fertilizer and pesticides.pesticides.

About 10 units of nonrenewable fossil fuel About 10 units of nonrenewable fossil fuel energy are needed to put 1 unit of food energy are needed to put 1 unit of food energy on the table.energy on the table.

Case Study: Industrialized Food Case Study: Industrialized Food Production in the United StatesProduction in the United States

Industrialized agriculture uses about 17% of Industrialized agriculture uses about 17% of all commercial energy in the U.S. and food all commercial energy in the U.S. and food travels an average 2,400 kilometers from travels an average 2,400 kilometers from farm to plate.farm to plate.


Fig. 13-7, p. 277

4%

Food production

Food distribution and preparation

Food processing

LivestockCrops5%6%2% 17%

of total U.S. commercial energy use

Traditional Agriculture: Low Input Traditional Agriculture: Low Input PolyculturePolyculture

Many farmers in developing countries use low-Many farmers in developing countries use low-input agriculture to grow a variety of crops on input agriculture to grow a variety of crops on each plot of land (interplanting) through:each plot of land (interplanting) through: Polyvarietal cultivationPolyvarietal cultivation: planting several genetic : planting several genetic

varieties.varieties. IntercroppingIntercropping: two or more different crops grown : two or more different crops grown

at the same time in a plot.at the same time in a plot. AgroforestryAgroforestry: crops and trees are grown together.: crops and trees are grown together. PolyculturePolyculture: different plants are planted together.: different plants are planted together.

Traditional Agriculture: Low Input Traditional Agriculture: Low Input PolyculturePolyculture

Research has Research has shown that, on shown that, on average, low input average, low input polyculture produces polyculture produces higher yields than higher yields than high-input high-input monoculture.monoculture.


SOIL EROSION AND DEGRADATIONSOIL EROSION AND DEGRADATION

Soil erosion lowers soil fertility and can Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded overload nearby bodies of water with eroded sediment.sediment. Sheet erosionSheet erosion: surface water or wind peel off : surface water or wind peel off

thin layers of soil.thin layers of soil. Rill erosionRill erosion: fast-flowing little rivulets of surface : fast-flowing little rivulets of surface

water make small channels.water make small channels. Gully erosionGully erosion: fast-flowing water join together to : fast-flowing water join together to

cut wider and deeper ditches or gullies.cut wider and deeper ditches or gullies.

SOIL EROSION AND DEGRADATIONSOIL EROSION AND DEGRADATION

Soil erosion is the Soil erosion is the movement of soil movement of soil components, components, especially surface especially surface litter and topsoil, by litter and topsoil, by wind or water.wind or water.

Soil erosion increases through activities Soil erosion increases through activities such as farming, logging, construction, such as farming, logging, construction, overgrazing, and off-road vehicles.overgrazing, and off-road vehicles.


Global Outlook: Soil ErosionGlobal Outlook: Soil Erosion

Soil is eroding faster than it is forming on more Soil is eroding faster than it is forming on more than one-third of the worldthan one-third of the world’’s cropland.s cropland.


Fig. 13-10, p. 279

Some concern

Serious concern

Stable or nonvegetative

Case Study: Soil Erosion in the U.S. – Case Study: Soil Erosion in the U.S. – Some Hopeful SignsSome Hopeful Signs

Soil erodes faster than it forms on most U.S. Soil erodes faster than it forms on most U.S. cropland, but since 1985, has been cut by cropland, but since 1985, has been cut by about 40%.about 40%. 1985 Food Security Act (Farm Act): farmers 1985 Food Security Act (Farm Act): farmers

receive a subsidy for taking highly erodible land receive a subsidy for taking highly erodible land out of production and replanting it with soil saving out of production and replanting it with soil saving plants for 10-15 years.plants for 10-15 years.

Fig. 13-11, p. 280

Very severeSevereModerate

Desertification: Degrading DrylandsDesertification: Degrading Drylands

About one-third of the worldAbout one-third of the world’’s land has lost s land has lost some of its productivity because of drought some of its productivity because of drought and human activities that reduce or degrade and human activities that reduce or degrade topsoil.topsoil.


Fig. 13-12, p. 280

Causes Consequences Overgrazing Worsening

droughtDeforestationFamineErosionEconomic losses

SalinizationLower living standardsSoil compaction

Natural climate change

Environmental refugees

Salinization Salinization and and

WaterloggingWaterlogging Repeated Repeated

irrigation can irrigation can reduce crop reduce crop yields by yields by causing salt causing salt buildup in the buildup in the soil and soil and waterlogging of waterlogging of crop plants.crop plants.


Fig. 13-13, p. 281

EvaporationTranspiration

EvaporationEvaporation

Waterlogging

Salinization Waterlogging1. Irrigation water contains small amounts of dissolved salts

2. Evaporation and transpiration leave salts behind.

3. Salt builds up in soil.

1. Precipitation and irrigation water percolate downward.

2. Water table rises.

Less permeable clay layer

Fig. 13-15, p. 281

CleanupPrevention

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)

Salinization and Waterlogging of Salinization and Waterlogging of Soils: A Downside of IrrigationSoils: A Downside of Irrigation

Example of high Example of high evaporation, evaporation, poor drainage, poor drainage, and severe and severe salinization.salinization.

White alkaline White alkaline salts have salts have displaced cops.displaced cops.


SUSTAINABLE AGRICULTURE SUSTAINABLE AGRICULTURE THROUGH SOIL CONSERVATIONTHROUGH SOIL CONSERVATION

Modern farm machinery can plant crops Modern farm machinery can plant crops without disturbing soil (no-till and minimum without disturbing soil (no-till and minimum tillage.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.


Terracing, contour Terracing, contour planting, strip planting, strip cropping, alley cropping, alley cropping, and cropping, and windbreaks can windbreaks can reduce soil reduce soil erosion.erosion.



Fertilizers can help restore soil nutrients, but Fertilizers can help restore soil nutrients, but runoff of inorganic fertilizers can cause water runoff of inorganic fertilizers can cause water pollution.pollution. Organic fertilizersOrganic fertilizers: from plant and animal (fresh, : from plant and animal (fresh,

manure, or compost) materials.manure, or compost) materials. Commercial inorganic fertilizersCommercial inorganic fertilizers: Active : Active

ingredients contain nitrogen, phosphorous, and ingredients contain nitrogen, phosphorous, and potassium and other trace nutrients.potassium and other trace nutrients.

THE GREEN REVOLUTION AND ITS THE GREEN REVOLUTION AND ITS ENVIRONMENTAL IMPACTENVIRONMENTAL IMPACT

Since 1950, high-input agriculture has Since 1950, high-input agriculture has produced more crops per unit of land.produced more crops per unit of land.

In 1967, fast growing dwarf varieties of rice In 1967, fast growing dwarf varieties of rice and wheat were developed for tropics and and wheat were developed for tropics and subtropics.subtropics.



Lack of water, high costs for small farmers, Lack of water, high costs for small farmers, and physical limits to increasing crop yields and physical limits to increasing crop yields hinder expansion of the green revolution.hinder expansion of the green revolution.

Since 1978 the amount of irrigated land per Since 1978 the amount of irrigated land per person has declined due to: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.


Modern agriculture has a greater harmful Modern agriculture has a greater harmful environmental impact than any human environmental impact than any human activity.activity.

Loss of a variety of genetically different crop Loss of a variety of genetically different crop and livestock strains might limit raw material and livestock strains might limit raw material needed for future green and gene needed for future green and gene revolutions.revolutions. In the U.S., 97% of the food plant varieties In the U.S., 97% of the food plant varieties

available in the 1940 no longer exist in large available in the 1940 no longer exist in large quantities.quantities.

Fig. 13-18, p. 285

Biodiversity Loss Soil Water Air Pollution Human 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

THE GENE REVOLUTIONTHE GENE REVOLUTION

To increase crop yields, we can mix the To increase crop yields, we can mix the genes of similar types of organisms and mix genes of similar types of organisms and mix the genes of different organisms.the genes of different organisms. Artificial selection has been used for centuries to Artificial selection has been used for centuries to

develop genetically improved varieties of crops.develop genetically improved varieties of crops. Genetic engineering develops improved strains Genetic engineering develops improved strains

at an exponential pace compared to artificial at an exponential pace compared to artificial selection.selection.

Controversy has arisen over the use of Controversy has arisen over the use of genetically modified food (GMF).genetically modified food (GMF).

Mixing GenesMixing Genes

Genetic engineering Genetic engineering involves splicing a involves splicing a gene from one gene from one species and species and transplanting the transplanting the DNA into another DNA into another species.species.


Fig. 13-19, p. 287

Projected DisadvantagesIrreversible and unpredictable genetic and ecological effects

Need less fertilizer

Need less water

More resistant to insects, disease, frost, and drought

Harmful toxins in food from possible plant cell mutations

Grow faster New allergens in food

Can grow in slightly salty soils

Lower nutrition

Less spoilage

Increased development of pesticide-resistant insects and plant diseases

Need less pesticidesCan create herbicide-resistant weeds

Better flavor

Tolerate higher levels of herbicides

Can harm beneficial insects

Lower genetic diversityHigher yields

Trade-Offs

Genetically Modified Crops and Foods

Projected Advantages


The winged bean, a The winged bean, a GMF, could be grown GMF, could be grown to help reduce to help reduce malnutrition and the malnutrition and the use of large amounts use of large amounts of inorganic of inorganic fertilizers.fertilizers.


How Would You Vote?How Would You Vote?

To conduct an instant in-class survey using a classroom response To conduct an instant in-class survey using a classroom response system, access system, access ““JoinIn Clicker ContentJoinIn Clicker Content”” from the PowerLecture main from the PowerLecture main menu for Living in the Environment.menu for Living in the Environment.

Do the advantages of genetically engineered Do the advantages of genetically engineered foods outweigh their disadvantages?foods outweigh their disadvantages? a. No. The impact of these foods could cause a. No. The impact of these foods could cause

serious harm to the environment or human serious harm to the environment or human health.health.

b. Yes. These foods are needed to combat world b. Yes. These foods are needed to combat world hunger. hunger.


Controversy has arisen over the use of Controversy has arisen over the use of genetically modified food (GMF).genetically modified food (GMF). Critics fear that we know too little about the long-Critics fear that we know too little about the long-

term potential harm to human and ecosystem term potential harm to human and ecosystem health.health.

There is controversy over legal ownership of There is controversy over legal ownership of genetically modified crop varieties and genetically modified crop varieties and whether GMFs should be labeled.whether GMFs should be labeled.



Should labeling of GMFs be required?Should labeling of GMFs be required? a. Yes, people have the right to make informed a. Yes, people have the right to make informed

decisions about what they are buying. decisions about what they are buying. b. No, research shows that GM organisms are b. No, research shows that GM organisms are

safe. Labeling will scare consumers and penalize safe. Labeling will scare consumers and penalize producers. producers.

PRODUCING MORE MEATPRODUCING MORE MEAT

About half of the worldAbout half of the world’’s meat is produced by s meat is produced by livestock grazing on grass.livestock grazing on grass.

The other half is produced under factory-like The other half is produced under factory-like conditions (feedlots).conditions (feedlots). Densely packed livestock are fed grain or fish Densely packed livestock are fed grain or fish

meal.meal. Eating more chicken and farm-raised fish and Eating more chicken and farm-raised fish and

less beef and pork reduces harmful less beef and pork reduces harmful environmental impacts of meat production.environmental impacts of meat production.

Fig. 13-21, p. 289

Trade-Offs

Animal Feedlots

Advantages Disadvantages

Increased meat production

Need large inputs of grain, fish meal, water, and fossil fuelsHigher 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

How Many People can the World How Many People can the World Support? Food Production and Support? Food Production and

PopulationPopulation

The number of people the world can support The number of people the world can support depends mostly on their per capita depends mostly on their per capita consumption of grain and meat and how consumption of grain and meat and how many children couples have.many children couples have. Research has shown that those living very low Research has shown that those living very low

on the food chain or very high on the food chain on the food chain or very high on the food chain do not live as long as those that live somewhere do not live as long as those that live somewhere in between.in between.

PRODUCING MORE MEATPRODUCING MORE MEAT

Efficiency of converting grain into animal Efficiency of converting grain into animal protein.protein.


Fig. 13-22, p. 290

Kilograms of grain needed per kilogram of body weight

Beef cattle 7

Pigs 4

Chicken 2.2

2

Fish (catfish or

carp)

CATCHING AND RAISING MORE CATCHING AND RAISING MORE FISH AND SHELLFISHFISH AND SHELLFISH

After spectacular increases, the worldAfter spectacular increases, the world’’s total s total and per capita marine and freshwater fish and per capita marine and freshwater fish and shellfish catches have leveled off.and shellfish catches have leveled off.


Fig. 13-23, p. 291

Wild catch

Cat

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mil

lio

ns

of

met

ric

ton

s)

Aquaculture Per

cap

ita

catc

h

(kil

og

ram

s p

er p

erso

n)

Year

Total World Fish Catch World Fish Catch per Person

Year

CATCHING AND RAISING MORE CATCHING AND RAISING MORE FISH AND SHELLFISHFISH AND SHELLFISH

Government subsidies given to the fishing Government subsidies given to the fishing industry are a major cause of overfishing.industry are a major cause of overfishing. Global fishing industry spends about $25 billion Global fishing industry spends about $25 billion

per year more than its catch is worth.per year more than its catch is worth. Without subsidies many fishing fleets would have Without subsidies many fishing fleets would have

to go out of business.to go out of business. Subsidies allow excess fishing with some Subsidies allow excess fishing with some

keeping their jobs longer with making less keeping their jobs longer with making less money.money.



Should governments eliminate most fishing Should governments eliminate most fishing subsidies?subsidies? a. No. At least some subsidies are needed for the a. No. At least some subsidies are needed for the

fishing industry to survive and provide needed fishing industry to survive and provide needed food for people.food for people.

b. Yes. Government subsidies only encourage b. Yes. Government subsidies only encourage overfishing. overfishing.

Aquaculture: Aquatic FeedlotsAquaculture: Aquatic Feedlots

Raising large numbers of fish and shellfish in Raising large numbers of fish and shellfish in ponds and cages is worldponds and cages is world’’s fastest growing s fastest growing type of food production.type of food production.

Fish farming involves cultivating fish in a Fish farming involves cultivating fish in a controlled environment and harvesting them controlled environment and harvesting them in captivity.in captivity.

Fish ranching involves holding anadromous Fish ranching involves holding anadromous species that live part of their lives in species that live part of their lives in freshwater and part in saltwater.freshwater and part in saltwater. Fish are held for the first few years, released, Fish are held for the first few years, released,

and then harvested when they return to spawn.and then harvested when they return to spawn.

Fig. 13-24, p. 292

Trade-Offs

Aquaculture


High efficiency Needs 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

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



Do the advantages of aquaculture outweigh Do the advantages of aquaculture outweigh its disadvantages?its disadvantages? a. No. Although there are advantages, a. No. Although there are advantages,

aquaculture causes significant environmental aquaculture causes significant environmental damage.damage.

b. Yes. Aquaculture can protect wild marine b. Yes. Aquaculture can protect wild marine species from commercial extinction. species from commercial extinction.

SOLUTIONS: MOVING TOWARD SOLUTIONS: MOVING TOWARD GLOBAL FOOD SECURITYGLOBAL FOOD SECURITY

People in urban areas People in urban areas could save money by could save money by growing more of their growing more of their food.food. Urban gardens provide Urban gardens provide

about 15% of the worlabout 15% of the worldd’’s food supply.s food supply.

Up to 90% of the Up to 90% of the worldworld’’s food is wasted.s food is wasted.


Government Policies and Food Government Policies and Food ProductionProduction

Governments use three main approaches to Governments use three main approaches to influence food production:influence food production: Control pricesControl prices to keep prices artificially low. to keep prices artificially low. Provide subsidiesProvide subsidies to keep farmers in business. to keep farmers in business. Let the marketplace decideLet the marketplace decide rather that rather that

implementing price controls.implementing price controls.



Should governments phase out subsidies for Should governments phase out subsidies for conventional industrialized agriculture and phase in conventional industrialized agriculture and phase in subsidies for more sustainable agriculture?subsidies for more sustainable agriculture? a. No. Current subsidies maintain critical food a. No. Current subsidies maintain critical food

supplies that should not be disrupted to Americans supplies that should not be disrupted to Americans and others.and others.

b. Yes. Agricultural pollution is a serious problem and b. Yes. Agricultural pollution is a serious problem and subsidies should be used to encourage subsidies should be used to encourage environmentally friendly agriculture.environmentally friendly agriculture.

Solutions: Steps Toward More Solutions: Steps Toward More Sustainable Food ProductionSustainable Food Production

We can increase food security by slowing We can increase food security by slowing populations growth, sharply reducing poverty, populations growth, sharply reducing poverty, and slowing environmental degradation of the and slowing environmental degradation of the worldworld’’s soils and croplands.s soils and croplands.

PROTECTING FOOD RESOURCES: PROTECTING FOOD RESOURCES: PEST MANAGEMENTPEST MANAGEMENT

Organisms found in Organisms found in nature (such as nature (such as spiders) control spiders) control populations of most populations of most pest species as part pest species as part of the earthof the earth’’s free s free ecological services.ecological services.



We use chemicals to repel or kill pest We use chemicals to repel or kill pest organisms as plants have done for millions of organisms as plants have done for millions of years.years.

Chemists have developed hundreds of Chemists have developed hundreds of chemicals (pesticides) that can kill or repel chemicals (pesticides) that can kill or repel pests.pests. Pesticides vary in their persistence.Pesticides vary in their persistence. Each year > 250,000 people in the U.S. become Each year > 250,000 people in the U.S. become

ill from household pesticides.ill from household pesticides.

Animation: Pesticide ExamplesAnimation: Pesticide Examples

PLAYANIMATION


Advantages and disadvantages of conventional Advantages and disadvantages of conventional chemical pesticides.chemical pesticides.


Fig. 13-28, p. 295


Save lives Promote genetic resistance

Increase food supplies Kill natural pest enemies

Profitable to use Create new pest species

Work fast Pollute the environment

Safe if used properly

Can harm wildlife and people

Individuals Matter: Rachel CarsonIndividuals Matter: Rachel Carson

Wrote Wrote Silent SpringSilent Spring which introduced the which introduced the U.S. to the dangers U.S. to the dangers of the pesticide DDT of the pesticide DDT and related and related compounds to the compounds to the environment.environment.

Figure 13-AFigure 13-A

The ideal Pesticide and the The ideal Pesticide and the Nightmare Insect PestNightmare Insect Pest

The ideal pest-killing chemical has these The ideal pest-killing chemical has these qualities:qualities: Kill only target pest.Kill only target pest. Not cause genetic resistance in the target Not cause genetic resistance in the target

organism.organism. Disappear or break down into harmless Disappear or break down into harmless

chemicals after doing its job.chemicals after doing its job. Be more cost-effective than doing nothing.Be more cost-effective than doing nothing.

SuperpestsSuperpests

Superpests are Superpests are resistant to resistant to pesticides.pesticides.

Superpests like the Superpests like the silver whiteflysilver whitefly (left) (left) challenge farmers challenge farmers as they cause > as they cause > $200 million per $200 million per year in U.S. crop year in U.S. crop losses.losses.


Pesticide Protection Laws in the U.S.Pesticide Protection Laws in the U.S.

Government regulation has banned a number Government regulation has banned a number of harmful pesticides but some scientists call of harmful pesticides but some scientists call for strengthening pesticide laws.for strengthening pesticide laws. The Environmental Protection Agency (EPA), the The Environmental Protection Agency (EPA), the

Department of Agriculture (USDA), and the Food Department of Agriculture (USDA), and the Food and Drug Administration (FDA) regulate the sales and Drug Administration (FDA) regulate the sales of pesticides under the Federal Insecticide, of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).Fungicide and Rodenticide Act (FIFRA).

The EPA has only evaluated the health effects of The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides.10% of the active ingredients of all pesticides.



Do the advantages of using synthetic Do the advantages of using synthetic chemical pesticides outweigh their chemical pesticides outweigh their disadvantages? disadvantages? a. No. Synthetic pesticides are overused, a. No. Synthetic pesticides are overused,

damage the environment, and increase cancer damage the environment, and increase cancer risks.risks.

b. Yes. Pesticides save human lives and protect b. Yes. Pesticides save human lives and protect crops. crops.

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.

Other Ways to Control PestsOther Ways to Control Pests

There are cultivation, biological, and There are cultivation, biological, and ecological alternatives to conventional ecological alternatives to conventional chemical pesticides.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.


Biological pest Biological pest controlcontrol: Wasp : Wasp parasitizing a parasitizing a gypsy moth gypsy moth caterpillar.caterpillar.



Genetic Genetic engineering can engineering can be used to be used to develop pest and develop pest and disease resistant disease resistant crop strains.crop strains.

Both tomato plants were exposed to Both tomato plants were exposed to destructive caterpillars. The genetically destructive caterpillars. The genetically altered plant (right) shows little damage.altered plant (right) shows little damage.


Case Study: integrated Pest Case Study: integrated Pest Management: A Component of Management: A Component of

Sustainable AgricultureSustainable Agriculture

An ecological approach to pest control uses a An ecological approach to pest control uses a mix of cultivation and biological methods, and mix of cultivation and biological methods, and small amounts of selected chemical small amounts of selected chemical pesticides as a last resort.pesticides as a last resort. Integrated Pest Management (IPM)Integrated Pest Management (IPM)

Case Study: integrated Pest Case Study: integrated Pest Management: A Component of Management: A Component of

Sustainable AgricultureSustainable Agriculture Many scientists urge the USDA to use three Many scientists urge the USDA to use three

strategies to promote IPM in the U.S.:strategies to promote IPM in the U.S.: Add a 2% sales tax on pesticides.Add a 2% sales tax on pesticides. Establish federally supported IPM demonstration Establish federally supported IPM demonstration

project for farmers.project for farmers. Train USDA personnel and county farm agents in Train USDA personnel and county farm agents in

IPM.IPM. The pesticide industry opposes such The pesticide industry opposes such

measures.measures.



Should governments heavily subsidize a Should governments heavily subsidize a switch to integrated pest management? switch to integrated pest management? a. No. Without extensive funding and training, a. No. Without extensive funding and training,

mere subsidies are not enough to successfully mere subsidies are not enough to successfully promote integrated pest management.promote integrated pest management.

b. Yes. These subsidies would decrease pollution b. Yes. These subsidies would decrease pollution and exposure to hazardous pesticides. and exposure to hazardous pesticides.

SOLUTIONS: SUSTAINABLE SOLUTIONS: SUSTAINABLE AGRICULTUREAGRICULTURE

Three main ways to reduce hunger and Three main ways to reduce hunger and malnutrition and the harmful effects of malnutrition and the harmful effects of agriculture:agriculture: Slow population growth.Slow population growth. Sharply reduce poverty.Sharply reduce poverty. Develop and phase in systems of more Develop and phase in systems of more

sustainable, low input agriculture over the next sustainable, low input agriculture over the next few decades.few decades.

Fig. 13-33, p. 302

Solutions

Sustainable Organic Agriculture

More Less

High-yield polyculture

Soil erosion

Soil salinizationOrganic fertilizers

Aquifer depletionBiological pest control Overgrazing

Integrated pest management

Overfishing

Loss of biodiversity

Efficient irrigation Loss of prime

croplandPerennial crops

Crop rotationFood waste

Water-efficient crops

Subsidies for unsustainable farming and fishing

Soil conservation

Subsidies for sustainable farming and fishing

Population growth

Poverty

Sustainable Sustainable AgricultureAgriculture

Results of 22 Results of 22 year study year study comparing comparing organic and organic and conventional conventional farming.farming.


Fig. 13-34, p. 302

Solutions

Organic Farming

Improves soil fertility

Reduces soil erosion

Retains more water in soil during drought years

Uses about 30% less energy per unit of yield

Lowers CO2 emissions

Reduces water pollution from recycling livestock wastes

Eliminates pollution from pesticides

Increases biodiversity above and below ground

Benefits wildlife such as birds and bats

Solutions: Making the Transition to Solutions: Making the Transition to More Sustainable AgricultureMore Sustainable Agriculture

More research, More research, demonstration demonstration projects, projects, government government subsidies, and subsidies, and training can training can promote more promote more sustainable sustainable organic organic agriculture.agriculture.


Fig. 13-35, p. 303

What Can You Do?

Sustainable Organic Agriculture

• Waste less food

• Eat less or no meat

• Feed pets balanced grain foods instead of meat

• Use organic farming to grow some of your food

• Buy organic food

• Eat locally grown food

• Compost food wastes

chapter 13 food, soil conservation, and pest management

Documents

food security

food resources

nutritious food

industrial food production

worlds food supply

important source of

green revolution slide

pest management slide