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Food, Soil, and Pest Management

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Title: Food, Soil, and Pest Management


1
Food, Soil, and Pest Management
  • Chapter 10

2
Three big ideas
  • 1billion do not get enough to eat and 1billion
    people eat too much.
  • Modern industrialized agriculture has a greater
    harmful impact on the environment than any other
    human activity.
  • More sustainable forms of food production will
    greatly reduce the harmful environmental impacts
    of industrialized food production systems while
    likely increasing food security.

3
What is food security and why is it difficult to
attain?
  • Section 10-1

4
Many people suffer from chronic health and
malnutrition
  • Food security means having daily access to enough
    nutritious food to live an active and healthy
    life.
  • One of every six people in less-developed
    countries is not getting enough to eat, facing
    food insecurityliving with chronic hunger and
    poor nutrition, which threatens their ability to
    lead healthy and productive lives.
  • The root cause of food insecurity is poverty.
  • Other obstacles to food security are political
    upheaval, war, corruption, and bad weather,
    including prolonged drought, flooding, and heat
    waves.

5
Starving children collecting ants in Sudan, Africa
6
Many people do not get enough vitamins and
minerals
  • Chronic lack of iodine can cause stunted growth,
    mental retardation, and goiter.
  • Almost one-third of the worlds people do not get
    enough iodine in their food and water.
  • According to the FAO and the WHO, eliminating
    this serious health problem would cost the
    equivalent of only 23 cents per year for every
    person in the world.

7
Oil palm plantation once covered with tropical
rain forest
8
Growth in global grain production of wheat, corn,
and rice between 1961-2010
9
Global seafood production, 1950-2008
10
Food productions harmful environmental effects
11
Topsoil erosion is a serious problem in some
parts of the world
12
Sand dunes threaten to take over an oasis in West
Africa
13
Variation in desertification in arid and semiarid
lands, 2007
14
Genetically modified crops and foods have
advantages and disadvantages
15
Soil conservation methods
16
Three types of systems commonly used to irrigate
crops
17
Ways to prevent soil salinization and ways to
clean it up
18
Practice more sustainable aquaculture
19
Animal feedlots and confined animal feeding
operations have advantages and disadvantages
20
Aquaculture has advantages and disadvantages
21
The efficiency of converting grain into animal
protein varies
22
More sustainable, low-input food production has a
number of major components
23
Major advantages of organic farming over
conventional
24
Ways you can eat more sustainably
25
Synthetic pesticides advantages and disadvantages
26
You can reduce your exposure to pesticides
27
Many people suffer from chronic health and
malnutrition
  • To maintain good health and resist disease,
    individuals need fairly large amounts of
    macronutrients, such as carbohydrates, proteins
    and fats, and smaller amounts of
    micronutrientsvitamins and minerals.
  • People who cannot grow or buy enough food to meet
    their basic energy needs suffer from chronic
    undernutrition, or hunger.
  • Many suffer from chronic malnutritiona
    deficiency of protein and other key nutrients,
    which weakens them, makes them more vulnerable to
    disease, and hinders the normal development of
    children.

28
Many people do not get enough vitamins and
minerals
  • Deficiency of one or more vitamins and minerals,
    usually vitamin A, iron, and iodine.
  • Some 250,000500,000 children younger than age 6
    go blind each year from a lack of vitamin A, and
    within a year, more than half of them die.
  • Lack of iron causes anemia which causes fatigue,
    makes infection more likely, and increases a
    womans chances of dying from hemorrhage in
    childbirth.
  • 1/5 people in the world suffers from iron
    deficiency.

29
Many people have health problems from eating too
much
  • Overnutrition occurs when food energy intake
    exceeds energy use, causing excess body fat.
  • Face similar health problems as those under
    lower life expectancy, greater susceptibility to
    disease and illness, and lower productivity and
    life quality.
  • Globally about 925 million people have health
    problems because they do not get enough to eat,
    and about 1.1 billion people face health problems
    from eating too much.
  • About 68 of American adults are overweight and
    half of those people are obese.
  • Obesity plays a role in four of the top ten
    causes of death in the United Statesheart
    disease, stroke, Type 2 diabetes, and some forms
    of cancer.

30
How is food produced?
  • Section 10-2

31
Food production has increased dramatically
  • About 10,000 years ago, humans began to shift
    from hunting for and gathering their food to
    growing it and raising animals for food and
    labor.
  • Today, three systems supply most of our food.
  • Croplands produce mostly grains.
  • Rangelands, pastures, and feedlots produce meat.
  • Fisheries and aquaculture provide us with
    seafood.
  • About 66 of the worlds people survive primarily
    by eating rice, wheat, and corn.
  • Only a few species of mammals and fish provide
    most of the worlds meat and seafood.

32
Food production has increased dramatically
  • Since 1960, there has been an increase in global
    food production from all three of the major food
    production systems because of technological
    advances.
  • Tractors, farm machinery and high-tech fishing
    equipment.
  • Irrigation.
  • Inorganic chemical fertilizers, pesticides,
    high-yield grain varieties, and industrialized
    production of livestock and fish.

33
Industrialized crop production relies on
high-input monocultures
  • Agriculture used to grow crops can be divided
    roughly into two types
  • Industrialized agriculture, or high-input
    agriculture, uses heavy equipment and large
    amounts of financial capital, fossil fuel, water,
    commercial inorganic fertilizers, and pesticides
    to produce single crops, or monocultures.
  • Major goal of industrialized agriculture is to
    increase yield, the amount of food produced per
    unit of land.
  • Used on about 25 of the worlds cropland, mostly
    in more-developed countries, and produces about
    80 of the worlds food.

34
Industrialized crop production relies on
high-input monocultures
  • Plantation agriculture is a form of
    industrialized agriculture used primarily in
    tropical less-developed countries.
  • Grows cash crops such as bananas, soybeans,
    sugarcane, coffee, palm oil, and vegetables.
  • Crops are grown on large monoculture plantations,
    mostly for export to more-developed countries.
  • Modern industrialized agriculture violates the
    three principles of sustainability by relying
    heavily on fossil fuels, reducing natural and
    crop biodiversity, and neglecting the
    conservation and recycling of nutrients in
    topsoil.

35
Traditional agriculture often relies on low-input
polycultures
  • Traditional agriculture provides about 20 of the
    worlds food crops on about 75 of its cultivated
    land, mostly in less-developed countries.
  • There are two main types of traditional
    agriculture.
  • Traditional subsistence agriculture supplements
    energy from the sun with the labor of humans and
    draft animals to produce enough crops for a farm
    familys survival, with little left over to sell
    or store as a reserve for hard times.
  • In traditional intensive agriculture, farmers
    increase their inputs of human and draft-animal
    labor, animal manure for fertilizer, and water to
    obtain higher crop yields, some of which can be
    sold for income.

36
Traditional agriculture often relies on low-input
polycultures
  • Many traditional farmers grow several crops on
    the same plot simultaneously, a practice known as
    polyculture.
  • Crop diversity reduces the chance of losing most
    or all of the years food supply to pests, bad
    weather, and other misfortunes.
  • Crops mature at different times, provide food
    throughout the year, reduce the input of human
    labor, and keep the soil covered to reduce
    erosion from wind and water.

37
Traditional agriculture often relies on low-input
polycultures
  • Lessens need for fertilizer and water, because
    root systems at different depths in the soil
    capture nutrients and moisture efficiently.
  • Insecticides and herbicides are rarely needed
    because multiple habitats are created for natural
    predators of crop-eating insects, and weeds have
    trouble competing with the multitude of crop
    plants.
  • On average, such low-input polyculture produces
    higher yields than does high-input monoculture.

38
A closer look at industrialized crop production
  • Farmers can produce more food by increasing their
    land or their yields per acre.
  • Since 1950, about 88 of the increase in global
    food production has come from using high-input
    industrialized agriculture to increase yields in
    a process called the green revolution.
  • Three steps of the green revolution
  • First, develop and plant monocultures of
    selectively bred or genetically engineered
    high-yield varieties of key crops such as rice,
    wheat, and corn.

39
A closer look at industrialized crop production
  • Second, produce high yields by using large inputs
    of water and synthetic inorganic fertilizers, and
    pesticides.
  • Third, increase the number of crops grown per
    year on a plot of land through multiple cropping.
  • The first green revolution used high-input
    agriculture to dramatically increase crop yields
    in most of the worlds more-developed countries,
    especially the United States, between 1950 and
    1970.

40
A closer look at industrialized crop production
  • A second green revolution has been taking place
    since 1967. Fast-growing varieties of rice and
    wheat, specially bred for tropical and
    subtropical climates, have been introduced into
    middle-income, less-developed countries such as
    India, China, and Brazil.
  • Producing more food on less land has helped to
    protect some biodiversity by preserving large
    areas of forests, grasslands, wetlands, and
    easily eroded mountain terrain that might
    otherwise be used for farming.

41
A closer look at industrialized crop production
  • Largely because of the two green revolutions,
    world grain production tripled between 1961 and
    2009.
  • People directly consume about 48 of the worlds
    grain production. About 35 is used to feed
    livestock and indirectly consumed by people who
    eat meat and meat products. The remaining 17
    (mostly corn) is used to make biofuels such as
    ethanol for cars and other vehicles.

42
A closer look at industrialized crop production
  • In the U.S., industrialized farming has evolved
    into agribusiness, as a small number of giant
    multinational corporations increasingly control
    the growing, processing, distribution, and sale
    of food in U.S. and global markets.
  • Since 1950 U.S. industrialized agriculture has
    more than doubled the yields of key crops such as
    wheat, corn, and soybeans without cultivating
    more land.
  • Americans spend only about 13 of their
    disposable income on food, compared to the
    percentages up to 50 that people in China and
    India and most other less-developed countries
    have to pay for food.

43
Crossbreeding and genetic engineering produce
varieties of crops and livestock
  • Crossbreeding through artificial selection has
    been used for centuries by farmers and scientists
    to develop genetically improved varieties of
    crops and livestock animals.
  • Such selective breeding in this first gene
    revolution has yielded amazing results ancient
    ears of corn were about the size of your little
    finger, and wild tomatoes were once the size of
    grapes.
  • Typically takes 15 years or more to produce a
    commercially valuable new crop variety, and it
    can combine traits only from genetically similar
    species.
  • Typically, resulting varieties remain useful for
    only 510 years before pests and diseases reduce
    their efficacy.

44
Crossbreeding and genetic engineering produce
varieties of crops and livestock
  • Modern scientists are creating a second gene
    revolution by using genetic engineering to
    develop genetically improved strains of crops and
    livestock.
  • Alters an organisms genetic material through
    adding, deleting, or changing segments of its DNA
    to produce desirable traits or to eliminate
    undesirable ones (gene splicing) resulting
    organisms are called genetically modified
    organisms.
  • Developing a new crop variety through gene
    splicing is faster selective breeding, usually
    costs less, and allows for the insertion of genes
    from almost any other organism into crop cells.

45
Crossbreeding and genetic engineering produce
varieties of crops and livestock
  • Currently, at least 70 of the food products on
    U.S. supermarket shelves contain some form of
    genetically engineered food or ingredients, but
    no law requires the labeling of GM products.
  • Certified organic food, which is labeled as makes
    no use of genetically modified seeds or
    ingredients.
  • Bioengineers plan to develop new GM varieties of
    crops that are resistant to heat, cold,
    herbicides, insect pests, parasites, viral
    diseases, drought, and salty or acidic soil. They
    also hope to develop crop plants that can grow
    faster and survive with little or no irrigation
    and with less fertilizer and pesticides.

46
Meat production has grown steadily
  • Meat and animal products such as eggs and milk
    are good sources of high-quality protein and
    represent the worlds second major food-producing
    system.
  • Between 1961 and 2010, world meat
    productionmostly beef, pork, and
    poultryincreased more than fourfold and average
    meat consumption per person more than doubled.
  • Global meat production is likely to more than
    double again by 2050 as affluence rises and more
    middle-income people begin consuming more meat
    and animal products in rapidly developing
    countries such as China and India.

47
Meat production has grown steadily
  • About half of the worlds meat comes from
    livestock grazing on grass in unfenced rangelands
    and enclosed pastures.
  • The other half is produced through an
    industrialized system in which animals are raised
    mostly in densely packed feedlots and
    concentrated animal feeding operations (CAFOs),
    where they are fed grain, fish meal, or fish oil,
    which are usually doctored with growth hormones
    and antibiotics.
  • Feedlots and CAFOs, and the animal wastes and
    runoff associated with them, create serious
    environmental impacts on the air and water.

48
Fish and shellfish production have increased
dramatically
  • The worlds third major food-producing system
    consists of fisheries and aquaculture.
  • A fishery is a concentration of particular
    aquatic species suitable for commercial
    harvesting in a given ocean area or inland body
    of water.
  • Industrial fishing fleets harvest most of the
    worlds marine catch of wild fish.

49
Fish and shellfish production have increased
dramatically
  • Fish and shellfish are also produced through
    aquaculturethe practice of raising marine and
    freshwater fish in freshwater ponds and rice
    paddies or in underwater cages in coastal waters
    or in deeper ocean waters.
  • Some fishery scientists warn that unless we
    reduce overfishing and ocean pollution, and slow
    projected climate change, most of the worlds
    major commercial ocean fisheries could collapse
    by 2050.

50
Industrialized food production requires huge
inputs of energy
  • The industrialization of food production has been
    made possible by the availability of energy,
    mostly from nonrenewable oil and natural gas.
  • Energy is needed to run farm machinery, irrigate
    crops, and produce synthetic pesticides and
    synthetic inorganic fertilizers, as well as to
    process food and transport it long distances
    within and between countries.
  • As a result, producing, processing, transporting,
    and consuming industrialized food result in a
    large net energy loss.

51
What environmental problems arise from
industrialized food production?
  • Section 10-3

52
Producing food has major environmental impacts
  • Spectacular increases in the worlds food
    production since 1950. The bad news is the
    harmful environmental effects associated with
    such production increases.
  • According to many analysts, agriculture has a
    greater total harmful environmental impact than
    any human activity.
  • These environmental effects may limit future food
    production and make it unsustainable.

53
Topsoil erosion is a serious problem in parts of
the world
  • Soil erosion is the movement of soil components,
    especially surface litter and topsoil from one
    place to another by the actions of wind and
    water.
  • Erosion of topsoil has two major harmful effects.
  • Loss of soil fertility through depletion of
    plant nutrients in topsoil.
  • Water pollution in nearby surface waters, where
    eroded topsoil ends up as sediment. This can kill
    fish and shellfish and clog irrigation ditches,
    boat channels, reservoirs, and lakes.

54
Topsoil erosion is a serious problem in parts of
the world
  • By removing vital plant nutrients from topsoil
    and adding excess plant nutrients to aquatic
    systems, we degrade the topsoil and pollute the
    water, and thus alter the carbon, nitrogen, and
    phosphorus cycles.

55
Drought and human activities are degrading
drylands
  • Desertification in arid and semiarid parts of the
    world threatens livestock and crop contributions
    to the worlds food supply.
  • Desertification occurs when the productive
    potential of topsoil falls by 10 or more because
    of a combination of prolonged drought and human
    activities that expose topsoil to erosion.
  • The FAOs 2007 report on the Status of the
    Worlds Forests estimated that some 70 of
    worlds arid and semiarid lands used for
    agriculture are degraded and threatened by
    desertification.

56
Excessive irrigation has serious consequences
  • Irrigation boosts productivity of farms roughly
    20 of the worlds cropland that is irrigated
    produces about 45 of the worlds food.
  • Most irrigation water is a dilute solution of
    various salts that are picked up as the water
    flows over or through soil and rocks.
  • Repeated annual applications of irrigation water
    in dry climates lead to the gradual accumulation
    of salts in the upper soil layersa soil
    degradation process called salinization that
    stunts crop growth, lowers crop yields, and can
    eventually kill plants and ruin the land.

57
Excessive irrigation has serious consequences
  • Severe salinization has reduced yields on at
    least 10 of the worlds irrigated cropland, and
    almost 25 of irrigated cropland in the United
    States, especially in western states
  • Irrigation can cause waterlogging, in which water
    accumulates underground and gradually raises the
    water table at least one-tenth of the worlds
    irrigated land suffers from waterlogging, and the
    problem is getting worse.
  • Excessive irrigation contributes to depletion of
    groundwater and surface water supplies.

58
Agriculture contributes to air pollution and
projected climate change
  • Agricultural activities create a lot of air
    pollution.
  • Account for more than 25 of the human-generated
    emissions of carbon dioxide, other greenhouse
    gases.
  • Industrialized livestock production alone
    generates about 18 of the worlds greenhouse
    gases cattle and dairy cows release the
    greenhouse gas methane and methane is generated
    by liquid animal manure stored in waste lagoons.
  • Nitrous oxide, with about 300 times the warming
    capacity of CO2 per molecule, is released in huge
    quantities by synthetic inorganic fertilizers as
    well as by livestock manure.

59
Food and biofuel production systems have caused
major losses of biodiversity
  • Natural biodiversity and some ecological services
    are threatened when forests are cleared and
    grasslands are plowed up and replaced with
    croplands used to produce food or biofuels, such
    as ethanol.
  • There is increasing loss of agrobiodiversity, the
    worlds genetic variety of animal and plant
    species.
  • In the United States, about 97 of the food plant
    varieties that were available to farmers in the
    1940s no longer exist, except perhaps in small
    amounts in seed banks and in the backyards of a
    few gardeners.
  • The worlds genetic library, which is critical
    for increasing food yields, is rapidly shrinking.

60
There is controversy over genetically engineered
foods
  • Controversy has arisen over the use of
    genetically modified (GM) food and other products
    of genetic engineering.
  • Its producers and investors see GM food as a
    potentially sustainable way to solve world hunger
    problems and improve human health.
  • Some critics consider it potentially dangerous
    Frankenfood.
  • Recognize the potential benefits of GM crops.
  • Warn that we know too little about the long-term
    potential harm to human health and ecosystems
    from the widespread use of such crops.

61
There is controversy over genetically engineered
foods
  • Warn that GM organisms released into the
    environment may cause some unintended harmful
    genetic and ecological effects.
  • Genes in plant pollen from GM crops can spread
    among nonengineered species. The new strains can
    then form hybrids with wild crop varieties, which
    could reduce the natural genetic biodiversity of
    wild strains.
  • Most scientists and economists who have evaluated
    the genetic engineering of crops believe that its
    potential benefits will eventually outweigh its
    risks.
  • Others have serious doubts about the ability of
    GM crops to increase food security compared to
    other more effective and sustainable alternative
    solutions.

62
There are limits to expansion of the green
revolution
  • Factors that have limited the current and future
    success of the green revolution
  • Without huge inputs of inorganic fertilizer,
    pesticides, and water, most green revolution and
    genetically engineered crop varieties produce
    yields that are no higher (and are sometimes
    lower) than those from traditional strains.
  • High inputs cost too much for most subsistence
    farmers in less-developed countries.

63
There are limits to expansion of the green
revolution
  • Scientists point out that continuing to increase
    these inputs eventually produces no additional
    increase in crop yields.
  • Since 1978, the amount of irrigated land per
    person has been declining, due to population
    growth, wasteful use of irrigation water, soil
    salinization, and depletion of both aquifers and
    surface water, and the fact that most of the
    worlds farmers do not have enough money to
    irrigate their crops.
  • We can get more crops per drop of irrigation
    water by using known methods and technologies to
    greatly improve the efficiency of irrigation.

64
There are limits to expansion of the green
revolution
  • Clearing tropical forests and irrigating arid
    land could more than double the worlds cropland,
    but much of this land has poor soil fertility,
    steep slopes, or both.
  • Cultivating such land usually is expensive, is
    unlikely to be sustainable, and reduces
    biodiversity by degrading and destroying wildlife
    habitats
  • During this century, fertile croplands in coastal
    areas are likely to be flooded by rising sea
    levels resulting from projected climate change.
  • Food production could drop sharply in some major
    food-producing areas because of increased drought
    and longer and more intense heat waves, also
    resulting from projected climate change.

65
Industrialized meat production has harmful
environmental consequences
  • Producing meat by using feedlots and other
    confined animal production facilities increases
    meat production, reduces overgrazing, and yields
    higher profits.
  • Such systems use large amounts of energy (mostly
    fossil fuels) and water and produce huge amounts
    of animal waste that sometimes pollute surface
    water and groundwater and saturate the air with
    their odors and emitting large quantities of
    climate-changing greenhouse gases into the
    atmosphere.

66
Industrialized meat production has harmful
environmental consequences
  • Meat produced by industrialized agriculture is
    artificially cheap harmful environmental and
    health costs are not included in the prices.
  • Overgrazing and soil compaction and erosion by
    livestock have degraded about 20 of the worlds
    grasslands and pastures.
  • Rangeland grazing and industrialized livestock
    production cause about 55 of all topsoil erosion
    and sediment pollution, and 33 of the water
    pollution that results from runoff from excessive
    inputs of synthetic fertilizers.

67
Industrialized meat production has harmful
environmental consequences
  • The use of fossil fuels energy pollutes the air
    and water, and emits greenhouse gases.
  • Use of antibiotics is widespread in
    industrialized livestock production facilities.
  • 70 of all antibiotics used in the United States
    are added to animal feed to prevent the spread of
    diseases in crowded feedlots and CAFOs and to
    make the livestock animals grow faster.

68
Industrialized meat production has harmful
environmental consequences
  • Widespread antibiotic use in livestock is an
    important factor in the rise of genetic
    resistance among many disease-causing microbes.
  • Reduces the effectiveness of some antibiotics
    used to treat infectious diseases in humans.
  • Promotes the development of new and aggressive
    disease organisms that are resistant to all but a
    very few antibiotics currently available.
  • Animal waste produced by U.S. meat is roughly 130
    times that of its human population.

69
How can we protect crops from pests more
sustainably?
  • Section 10-4

70
Nature controls the populations of most pests
  • A pest is any species that interferes with human
    welfare by competing with us for food, invading
    homes, lawns and gardens, destroying building
    materials, spreading disease, invading
    ecosystems, or simply being a nuisance.
  • Worldwide, only about 100 species of plants
    (weeds), animals (mostly insects), fungi, and
    microbes cause most of the damage to the crops we
    grow.

71
Nature controls the populations of most pests
  • In natural ecosystems and many polyculture
    agroecosystems, natural enemies (predators,
    parasites, and disease organisms) control the
    populations of most potential pest species.
  • Spiders kill far more crop-eating insects every
    year than humans do by using chemicals.
  • When we clear forests and grasslands, plant
    monoculture crops, and douse fields with
    chemicals that kill pests, we upset many of these
    natural population checks and balances that help
    to maintain biodiversity.

72
We use pesticides to help control pest populations
  • Development of a variety of synthetic
    pesticideschemicals used to kill/control
    populations of organisms that we consider
    undesirable such as insects, weeds, and mice.
  • Common types of pesticides include insecticides
    (insect killers), herbicides (weed killers),
    fungicides (fungus killers), and rodenticides
    (rat and mouse killers).
  • Plants produce chemicals called biopesticides to
    ward off, deceive, or poison the insects and
    herbivores that feed on them.
  • Since 1950, pesticide use has increased more than
    50-fold, and most of todays pesticides are
    10100 times more toxic than those used in the
    1950s.
  • Use of biopesticides is on the rise.

73
We use pesticides to help control pest populations
  • Broad-spectrum agents are toxic to many pests,
    but also to beneficial species. Examples are
    chlorinated hydrocarbon compounds, such as DDT,
    and organophosphate compounds, such as malathion
    and parathion.
  • Selective, or narrow spectrum, agents are
    effective against a narrowly defined group of
    organisms. Examples are algaecides for algae and
    fungicides for fungi.

74
We use pesticides to help control pest populations
  • Pesticides vary in their persistence, the length
    of time they remain deadly in the environment.
  • DDT and related compounds remain in the
    environment for years and can be biologically
    magnified in food chains and webs.
  • Organophosphates are active for days or weeks and
    are not biologically magnified but can be highly
    toxic to humans.

75
We use pesticides to help control pest populations
  • In the United States, about 25 of pesticide use
    is on houses, gardens, lawns, parks, playing
    fields, swimming pools, and golf courses, with
    the average lawn receiving ten times more
    synthetic pesticides per unit of land area than
    an equivalent amount of cropland.
  • In 1962, biologist Rachel Carson warned against
    relying primarily on synthetic organic chemicals
    to kill insects and other species we regard as
    pests.

76
Pesticide use has not reduced U.S. crop losses to
pests
  • Synthetic pesticide use has not reduced U.S. crop
    losses to pests, mostly because of genetic
    resistance and reduction of natural predators.
  • Three conclusions from a study that evaluated
    data from more than 300 agricultural scientists
    and economists
  • Between 1942 and 1997, estimated crop losses from
    insects almost doubled from 7 to 13, despite a
    10-fold increase in the use of synthetic
    insecticides.

77
Pesticide use has not reduced U.S. crop losses to
pests
  • The estimated environmental, health, and social
    costs of pesticide use in the United States are
    510 in damages for every dollar spent on
    pesticides.
  • Alternative pest management practices could cut
    the use of synthetic pesticides by half on 40
    major U.S. crops without reducing crop yields
  • The pesticide industry disputes these findings.

78
CASE STUDY Ecological Surprises The Law of
Unintended Consequences
  • In the 1950s, dieldrin (a DDT relative) was used
    to eliminate malaria in North Borneo. This
    started an unexpected chain of negative effects.
  • Small insect-eating lizards that lived in the
    houses died after eating dieldrin-contaminated
    insects. Cats died after feeding on the lizards.
    Rats flourished and villagers became threatened
    by plague carried by rat fleas.
  • The WHO successfully parachuted healthy cats onto
    the island to help control the rats.

79
CASE STUDY Ecological Surprises The Law of
Unintended Consequences
  • The villagers roofs fell in. The dieldrin had
    killed wasps and other insects that fed on a type
    of caterpillar that was not affected by the
    insecticide. The caterpillar population exploded,
    and ate the leaves used to thatch roofs.
  • Ultimately, both malaria and the unexpected
    effects of the spraying program were brought
    under control.

80
Laws and treaties can help to protect us from the
harmful effects of pesticides
  • In the U.S., three federal agencies, the EPA, the
    USDA, and the FDA regulate the sale and use of
    pesticides under the Federal Insecticide,
    Fungicide, and Rodenticide Act (FIFRA), first
    passed in 1947 and amended in 1972.
  • Under FIFRA, the EPA was supposed to assess the
    health risks of the active ingredients in
    synthetic pesticide products already in use.
  • After more than 30 years, less than 10 of the
    active ingredients in pesticide products have
    been tested for chronic health effects, due to
    lack of funding.

81
Laws and treaties can help to protect us from the
harmful effects of pesticides
  • In 1996, Congress passed the Food Quality
    Protection Act, due to growing scientific
    evidence and citizen pressure concerning the
    effects of small amounts of pesticides on
    children.
  • Act requires the EPA to reduce the allowed levels
    of pesticide residues in food by a factor of 10
    when there is inadequate information on the
    potentially harmful effects on children.
  • Between 1972 and 2010, the EPA used FIFRA to ban
    or severely restrict the use of 64 active
    pesticide ingredients, including DDT and most
    other chlorinated hydrocarbon insecticides.

82
Laws and treaties can help to protect us from the
harmful effects of pesticides
  • Up to 98 of the potential risk of developing
    cancer from pesticide residues on food grown in
    the U.S. would be eliminated if EPA standards
    were as strict for pre-1972 pesticides as they
    are for later ones.
  • Banned/unregistered pesticides may be
    manufactured in one country and exported to other
    countries.
  • In what environmental scientists call a circle of
    poison, or the boomerang effect, residues of some
    banned or unapproved chemicals used in synthetic
    pesticides exported to other countries can return
    to the exporting countries on imported food.

83
Laws and treaties can help to protect us from the
harmful effects of pesticides
  • The wind can also carry persistent pesticides
    from one country to another.
  • In 1998, more than 50 countries developed an
    international treaty that requires exporting
    countries to have informed consent from importing
    counties for exports of 22 synthetic pesticides
    and 5 industrial chemicals.
  • In 2000, more than 100 countries developed an
    international agreement to ban or phase out the
    use of 12 especially hazardous persistent organic
    pollutants. The U.S. has not signed.

84
There are alternatives to synthetic pesticides
  • Many scientists believe we should greatly
    increase the use of biological, ecological, and
    other alternative methods for controlling pests
    and diseases that affect crops and human health.
    Here are some of these alternatives
  • Fool the pest. A variety of cultivation practices
    can be used to fake out pests.
  • Provide homes for pest enemies.
  • Implant genetic resistance.

85
There are alternatives to synthetic pesticides
  • Bring in natural enemies. Use biological control
    by importing natural predators, parasites, and
    disease-causing bacteria and viruses.
  • Use insect perfumes.
  • Bring in the hormones.
  • Reduce use of synthetic herbicides to control
    weeds.

86
Integrated pest management is a component of more
sustainable agriculture
  • Many pest control experts and farmers believe the
    best way to control crop pests is a carefully
    designed integrated pest management (IPM)
    program.
  • Farmers develop a carefully designed control
    program that uses a combination of cultivation,
    biological, and chemical tools and techniques.
  • The overall aim of IPM is to reduce crop damage
    to an economically tolerable level.
  • Farmers first use biological methods (natural
    predators, parasites, and disease organisms) and
    cultivation controls (such as rotating crops,
    altering planting time, and using large machines
    to vacuum up harmful bugs).

87
Integrated pest management is a component of more
sustainable agriculture
  • They apply small amounts of insecticidesmostly
    based on those naturally produced by plantsonly
    when insect or weed populations reach a threshold
    where the potential cost of pest damage to crops
    outweighs the cost of applying the pesticide.
  • Broad-spectrum, long-lived pesticides are not
    used, and different chemicals are used
    alternately to slow the development of genetic
    resistance and to avoid killing predators of pest
    species.
  • A well-designed IPM program can reduce synthetic
    pesticide use and pest control costs by 5065,
    without reducing crop yields and food quality.

88
Integrated pest management is a component of more
sustainable agriculture
  • IPM can also reduce inputs of fertilizer and
    irrigation water, and slow the development of
    genetic resistance, because pests are attacked
    less often and with lower doses of pesticides.
  • Disadvantages of IPM
  • It requires expert knowledge about each pest
    situation and takes more time than does using
    conventional pesticides.
  • Methods developed for a crop in one area might
    not apply to areas with even slightly different
    growing conditions.

89
Integrated pest management is a component of more
sustainable agriculture
  • Initial costs may be higher, although long-term
    costs typically are lower than those of using
    conventional pesticides.
  • Widespread use of IPM is hindered in the United
    States and a number of other countries by
    government subsidies for using synthetic chemical
    pesticides, as well as by opposition from
    pesticide manufacturers, and a shortage of IPM
    experts.
  • The USDA could promote IPM three ways
  • First, add a 2 sales tax on synthetic pesticides
    and use the revenue to fund IPM research and
    education.

90
Integrated pest management is a component of more
sustainable agriculture
  • Second, set up a federally supported IPM
    demonstration project on at least one farm in
    every county in the United States.
  • Third, train USDA field personnel and county farm
    agents in IPM so they can help farmers use this
    alternative.
  • Because these measures would reduce its profits,
    the pesticide industry has vigorously, and
    successfully, opposed them.

91
How can we improve food security?
  • Section 10-5

92
Use government policies to improve food
production and security
  • Agriculture is a financially risky business
    because farmers have a good or bad year depending
    on factors over which they have little control
    weather, crop prices, crop pests and diseases,
    loan interest rates, and global markets.
  • Governments use two main approaches to influence
    food production
  • Control prices.
  • Provide subsidies.

93
Use government policies to improve food
production and security
  • To improve food security, some analysts urge
    governments to establish special programs focused
    on saving children from the harmful health
    effects of poverty.
  • Immunizing more children against childhood
    diseases.
  • Preventing dehydration from diarrhea by giving
    infants a mixture of sugar and salt in water.
  • Preventing blindness by giving children an
    inexpensive vitamin A capsule twice a year.

94
How can we produce food more sustainably?
  • Section 10-6

95
Reduce soil erosion
  • Soil conservation involves using a variety of
    ways to reduce soil erosion and restore soil
    fertility, mostly by keeping the soil covered
    with vegetation.
  • Some of the methods farmers can use to reduce
    soil erosion
  • Terracing and contour planting are ways to grow
    food on steep slopes without depleting topsoil.
  • Strip cropping involves planting alternating
    strips of a row crop and another crop that
    completely covers the soil, called a cover crop.

96
Reduce soil erosion
  • Alley cropping, or agroforestry involves one or
    more crops planted together in strips or alleys
    between trees and shrubs, which provide shade.
  • Farmers can establish windbreaks, or
    shelterbelts, of trees around crop fields to
    reduce wind erosion.
  • Conservation tillage farming by using special
    tillers and planting machines that drill seeds
    directly through crop residues into the
    undisturbed soil.
  • Retire the estimated one-tenth of the worlds
    marginal cropland that is highly erodible and
    accounts for the majority of the worlds topsoil
    erosion.

97
Reduce soil erosion
  • Soil erosion in the United States.
  • A third of the countrys original topsoil is gone
    and much of the rest is degraded.
  • In 1935, the United States passed the Soil
    Erosion Act, which established the Soil
    Conservation Service (SCS) as part of the USDA.
  • Now called the Natural Resources Conservation
    Service
  • Farmers and ranchers were given technical
    assistance to set up soil conservation programs.
  • U.S. farmers are sharply reducing some of their
    topsoil losses through a combination of
    conservation-tillage farming and
    government-sponsored soil conservation programs.

98
Restore soil fertility
  • Topsoil conservation is the best way to maintain
    soil fertility, with restoring some of the lost
    plant nutrients being the next option.
  • Organic fertilizer from plant and animal
    materials.
  • Animal manure the waste of cattle, horses,
    poultry, and other farm animals adding organic
    nitrogen, stimulating the growth of beneficial
    soil bacteria and fungi.
  • Green manure consists of freshly cut or growing
    green vegetation that is plowed into the topsoil
    to increase the organic matter and humus
    available to the next crop.
  • Compost is produced when microorganisms in soil
    break down organic matter in the presence of
    oxygen.

99
Restore soil fertility
  • Organic agriculture uses only organic fertilizers
    and crop rotation to replenish the nutrients.
  • Synthetic inorganic fertilizers are usually
    inorganic compounds that contain nitrogen,
    phosphorus, and potassium.
  • Inorganic fertilizer use has grown more than 900
    since 1950 now about one-fourth of the worlds
    crops.
  • Fertilizer runoff can pollute nearby bodies of
    water and coastal estuaries where rivers empty
    into the sea.
  • They do not replace organic matter. To completely
    restore nutrients to topsoil, both inorganic and
    organic fertilizers should be used.

100
Reduce soil salinization and desertification
  • One way to prevent and deal with soil
    salinization is to reduce the amount of water
    that is put onto crop fields through use of
    modern efficient irrigation.
  • Drip, or trickle irrigation, also called
    microirrigation, is the most efficient way to
    deliver small amounts of freshwater to crops
    precisely.
  • These systems drastically reduce freshwater waste
    because 9095 of the water input reaches the
    crops.
  • By using less freshwater, they also reduce the
    amount of harmful salt that irrigation water
    leaves in the soil.

101
Reduce soil salinization and desertification
  • Reducing desertification is not easy because we
    cant control the timing and location of
    prolonged droughts caused by changes in weather
    patterns.
  • We can reduce population growth, overgrazing,
    deforestation, and destructive forms of planting,
    irrigation, and mining, which have left much land
    vulnerable to soil erosion and thus
    desertification.
  • Work to decrease the human contribution to
    projected climate change, which is expected to
    increase severe and prolonged droughts in larger
    areas of the world during this century.
  • Restoration via planting trees.

102
Produce meat more efficiently and eat less meat
  • Meat production and consumption account for the
    largest contribution to the ecological footprints
    of most individuals in affluent nations.
  • If everyone in the world today was on the average
    U.S. meat-based diet, the current annual global
    grain harvest could sustainably feed only about
    one-third of the worlds current population.

103
Produce meat more efficiently and eat less meat
  • More sustainable meat production and consumption
    involves shifting from less grain-efficient forms
    of animal protein, (beef, carnivorous fish), to
    more grain-efficient forms (poultry, herbivorous
    farmed fish).
  • Eating less meat by having one meatless day per
    week.
  • Healthier to eat less meat.
  • Replace meat with a balanced vegetarian diet.

104
Shift to more sustainable food production
  • Industrialized agriculture produces large amounts
    of food at reasonable prices, but is
    unsustainable because it
  • Relies heavily on fossil fuels.
  • Reduces biodiversity and agrobiodiversity.
  • Reduces the recycling of plant nutrients back to
    topsoil.

105
Shift to more sustainable food production
  • More sustainable, low-input agriculture has a
    number of major components.
  • Organic farming.
  • Sharply reduces the harmful environmental effects
    of industrialized farming and our exposure to
    pesticides.
  • Encourages more humane treatment of animals used
    for food and is a more economically just system
    for farm workers and farmers.
  • Requires more human labor than industrial
    farming.
  • Yields can be lower but farmers do not have to
    pay for expensive synthetic pesticides,
    herbicides, and fertilizers typically get higher
    prices for their crops.

106
Shift to more sustainable food production
  • Organic polyculture.
  • A diversity of organic crops is grown on the same
    plot.
  • Use polyculture to grow perennial cropscrops
    that grow back year after year on their own.
  • Helps to conserve and replenish topsoil, requires
    and wastes less water, and reduces the need for
    fertilizers and pesticides.
  • Reduces the air and water pollution associated
    with conventional industrialized agriculture.
  • Shift from using imported fossil fuel to relying
    more on solar energy for food production.

107
Shift to more sustainable food production
  • Five major strategies to help farmers and
    consumers make the transition to more sustainable
    agriculture
  • Greatly increase research on more sustainable
    organic farming and perennial polyculture, and on
    improving human nutrition.
  • Establish education and training programs in more
    sustainable agriculture for students, farmers,
    and government agricultural officials.
  • Set up an international fund to give farmers in
    poor countries access to various types of more
    sustainable agriculture.

108
Shift to more sustainable food production
  1. Replace government subsidies for environmentally
    harmful forms of industrialized agriculture with
    subsidies that encourage more sustainable
    agriculture.
  2. Mount a massive program to educate consumers
    about the true environmental and health costs of
    the food they buy. This would help them
    understand why the current system is
    unsustainable, and it would help build political
    support for including the harmful costs of food
    production in the market prices of food.

109
Three big ideas
  • About 925 million people have health problems
    because they do not get enough to eat and 1.1
    billion people face health problems from eating
    too much.
  • Modern industrialized agriculture has a greater
    harmful impact on the environment than any other
    human activity.
  • More sustainable forms of food production will
    greatly reduce the harmful environmental impacts
    of industrialized food production systems while
    likely increasing food security.
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