Food, Soil, and Pest Management

1
Food, Soil, and Pest Management

• Chapter 10

2
What is food security and why is it difficult to
attain?

• Section 10-1

3
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.

4
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.

5
Starving children collecting ants in Sudan, Africa
6
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.

7
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.

8
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.

9
How is food produced?

• Section 10-2

10
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.

11
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.

12
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.

13
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.

14
Oil palm plantation once covered with tropical
rain forest
15
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.

16
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.

17
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.

18
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.

19
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.

20
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.

21
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.

22
Growth in global grain production of wheat, corn,
and rice between 1961-2010
23
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.

24
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.

25
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.

26
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.

27
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.

28
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.

29
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.

30
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.

31
Global seafood production, 1950-2008
32
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.

33
What environmental problems arise from
industrialized food production?

• Section 10-3

34
Food productions harmful environmental effects
35
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.

36
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.

37
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.

38
Topsoil erosion is a serious problem in some
parts of the world
39
Serious concern
Some concern
Stable or nonvegetative
Stepped Art
Fig. 10-11, p. 214
40
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.

41
Sand dunes threaten to take over an oasis in West
Africa
42
Variation in desertification in arid and semiarid
lands, 2007
43
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.

44
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.

45
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.

46
Genetically modified crops and foods have
advantages and disadvantages
47
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.

48
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.

49
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.

50
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.

51
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.

52
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.

53
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.

54
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.

55
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.

56
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.

57
Animal feedlots and confined animal feeding
operations have advantages and disadvantages
58
Aquaculture has advantages and disadvantages
59
How can we protect crops from pests more
sustainably?

• Section 10-4

60
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.

61
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.

62
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.

63
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.

64
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.

65
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.

66
Synthetic pesticides advantages and disadvantages
67
You can reduce your exposure to pesticides
68
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.

69
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.

70
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.

71
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.

72
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.

73
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.

74
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.

75
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.

76
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.

77
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.

78
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).

79
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.

80
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.

81
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.

82
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.

83
How can we improve food security?

• Section 10-5

84
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.

85
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.

86
How can we produce food more sustainably?

• Section 10-6

87
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.

88
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.

89
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.

90
Soil conservation methods
91
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.

92
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.

93
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.

94
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.

95
Three types of systems commonly used to irrigate
crops
96
Drip irrigation (efficiency 9095)
Center pivot (efficiency 80 with low-pressure
sprinkler and 9095 with LEPA sprinkler)
Above- or below-ground pipes or tubes deliver
water to individual plant roots.
Gravity flow (efficiency 60 and 80 with surge
valves)
Water usually pumped from underground and sprayed
from mobile boom with sprinklers.
Water usually comes from an aqueduct system or a
nearby river.
Fig. 10-24, p. 229
97
Ways to prevent soil salinization and ways to
clean it up
98
Practice more sustainable aquaculture
99
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.

100
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.

101
The efficiency of converting grain into animal
protein varies
102
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.

103
More sustainable, low-input food production has a
number of major components
104
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.

105
Major advantages of organic farming over
conventional
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
Ways you can eat more sustainably
110
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.