Food, Soil Conservation, and Pest Management

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Chapter 13

• Food, Soil Conservation, and Pest Management

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Soil- A renewable resource if maintained properly.

• Soil make-up

• How soil is formed

• Eroded rock
• Mineral nutrients
• Decaying organic matter
• Water
• Air
• Microorganisms

• Weathering
• Physical
• Wind, water, moving plates
• Chemical
• acids
• Biological
• Lichens, roots

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Why is soil so important?

• Nutrients needed by plants are in soil
• Nutrients by humans are then taken up by plants
  or animals that get them from the soil
• Water purifier
• Removes carbon from the atmosphere and stores it
  as carbon compounds

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Soil Layers

• Soil horizons are viewed through a soil profile
• O horizon surface litter
• A horizon topsoil and humus (partially
  decomposed plants and animals and clay, silt, and
  sand)
• B horizon subsoil
• C horizon parent rock
• Bedrock

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Soil profiles in different biomes
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Which biome(s) is most often converted to
cropland?

• Why do you think this is the case?

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Water movement through soil

• Infiltration- Waters natural movement down
  through soil dissolving minerals and organic
  matter and carrying them lower as it moves-
  leaching

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Soil properties

• Soil is composed of
• Clay- smallest particle size
• Silt- medium
• Sand- larger
• Loam is the best for plants. An even mixture of
  all three.

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Textural Triangle
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Soil properties continued

• Porosity or void fraction is a measure of the
  void (i.e., "empty") spaces in a material, and is
  a fraction of the volume of voids over the total
  volume, between 01, or as a percentage between
  0100.
• How much space is available to hold water.

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Which picture is more likely made up of a soil
like gravel? Sand?
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What is permeability?

• http//techalive.mtu.edu/meec/module06/Permeabilit
  y.htm

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How do porosity and permeability of soil relate?

• LAB!

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The relationship between Porosity and Permeability

• In some soils porosity and permeability have a
  direct relationship, as you have more pores water
  can flow through easier.
• In some soils porosity and permeability have an
  indirect relationship, as you have more pores
  there are more places for water to get trapped
  thus decreasing the permeability.
• It depends on medium type and compaction of the
  medium.

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Core Case Study What is Golden Rice?

• http//www.youtube.com/watch?vsbxA4WlkUP8

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FOOD SECURITY AND NUTRITION

• Global food production has stayed ahead of
  population growth. However
• One of six people in developing countries cannot
  grow or buy the food they need.
• Others cannot meet their basic energy needs
  (undernutrition / hunger) or protein and key
  nutrients (malnutrition).

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Food Challenges for the FUTURE

• 1)poverty
• 2)making and moving enough food to sustain a
  growing population
• 3)doing so sustainably (not degrading soil and
  water)
• Use of fossil fuels in farming
• Wastes from plants and animals
• Erosion of the soil
• Degradation of the minerals and vitamins from the
  soil
• Polluting water by increasing fertilizer run-off,
  animal waste run-off

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FOOD SECURITY AND NUTRITION

• Food security means that every person in a given
  area has daily access to enough nutritious food
  to have an active and healthy life.
• Need large amounts of macronutrients (protein,
  carbohydrates, and fats).
• Need smaller amounts of micronutrients (vitamins
  such as A,C, and E).
• Food Security Act of 1985- subsidy for taking
  highly eroded land and planting it with grasses
  to restore soil.

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FOOD SECURITY AND NUTRITION

• One in three people has a deficiency of one or
  more vitamins and minerals, especially vitamin A,
  iodine (causes goiter - enlargement of thyroid
  gland), and iron (causes anemia).
• Measles and diarrhea kill many children in
  developing countries.

Figure 13-2
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War and Corruption leading to Hunger

• Starving children collecting ants to eat in
  famine-stricken Sudan, Africa which has been
  involved in civil war since 1983.
• Money spent on weapons, manpower used for
  fighting, no stability, land maintained by rich
  only.

Figure 13-3
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Hunger from war

• http//www.youtube.com/user/WorldConcernVideos?vq
  6gYK7474sEfeaturepyv

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Solutions Reducing Childhood Deaths from Hunger
and Malnutrition

• There are several ways to reduce childhood deaths
  from nutrition-related causes
• Immunize children.
• Encourage breast-feeding.
• Prevent dehydration from diarrhea.
• Prevent blindness from vitamin A deficiency.
• Provide family planning.
• Increase education for women.

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Overnutrition Eating Too Much

• Over nutrition and lack of exercise can lead to
  reduced life quality, poor health, and premature
  death. ? The same problems undernourished people
  face.
• A 2005 Boston University study found that about
  60 of American adults are overweight and 33 are
  obese (totaling 93).
• Americans spend 42 billion per year trying to
  lose weight.
• 24 billion per year is needed to eliminate world
  hunger.

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FOOD PRODUCTION

• Croplands- grains, 77 of food on 11 of land
• 50 of most peoples diet is based on grains
• Rangelands- meat and cattle, 16 of food on 29
  of land
• Oceanic Fisheries and aquaculture- fish, 7 of
  food

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Industrial Food Production High Input
Monocultures

• About 80 of the worlds food supply is produced
  by industrialized agriculture.
• Uses large amounts of fossil fuel energy, water,
  commercial fertilizers, and pesticides to produce
  monocultures.
• Greenhouses are increasingly being used taking up
  natural flow of land. (can cause erosion issues)
• Plantations are being used in tropics for cash
  crops such as coffee, sugarcane, bananas.

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

• Livestock production in developed countries is
  industrialized
• Feedlots are used to fatten up cattle before
  slaughter.
• Most pigs and chickens live in densely populated
  pens or cages.
• Most livestock are fed grain grown on cropland.
• Systems use a lot of energy and water and produce
  huge amounts of animal waste. Lots of methane
  released (GHG).

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What is the Japan-syndrome?

• Industrialization? Less people farming? more
  /person ? more meat wanted by people that now
  have more money? more grain needed to feed
  animals? less land to grow grain because more
  land needed for urbanization and livestock

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Problems with sustainably growing enough food to
sustain growing population

• Soil erosion and depletion of minerals
• Water depletion and pollution from runoff
• Overgrazing
• Overfishing
• Increased fuel costs
• Increased atmospheric temperatures
• ALL LEAD TO BIODIVERSITY LOSS DUE TO HABITAT LOSS
  AND RESOURCE DEGRADATION

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Natural Capital
Croplands
Ecological Services
Economic Services
Help maintain water flow and soil infiltration
Food crops
Provide partial erosion protection
Fiber crops
Can build soil organic matter
Crop genetic resources
Store atmospheric carbon
Jobs
Provide wildlife habitat for some species
Fig. 13-6, p. 276
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Is food production in the US efficient?

• Yes

• No

• Food production doubled with no increase in land
  use since 1950.
• Mostly due to genetic engineering

• Net Energy Loss- 10 units of nonrenewable fossil
  fuels used to get 1 unit of food.

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Traditional Agriculture Low Input
Polycultureincreasing crop yields

• Many farmers in developing countries use
  low-input agriculture to grow a variety of crops
  on each plot of land, interplanting, through
• Polyvarietal cultivation planting several
  genetic varieties of the same crop.
• Intercropping two or more different crops grown
  at the same time in a plot. Ex. Grain that uses
  Nitrogen and legume that puts it back into the
  soil.

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• Agroforestry crops and trees are grown together.
  Trees provide shade and lower transpiration rate.
• Polyculture different plants are planted
  together and they mature at different times.
  Keeps ground covered with plants and reduces
  erosion.

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Traditional Agriculture Low Input Polyculture

• Research has shown that, on average, low input
  polyculture produces higher yields than
  high-input monoculture.
• Keeps soil fertile, helps with water purification.

Figure 13-8
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SOIL EROSION AND DEGRADATION

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

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Soil erosion problems and solutions

• http//www.youtube.com/watch?vQT7hklD2l2M

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Desertification Degrading Drylands

• About one-third of the worlds land has lost some
  of its productivity because of drought and human
  activities that reduce or degrade topsoil.
• Chinas dustbowl

Figure 13-12
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Salinization and Waterlogging

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

Figure 13-13
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Solutions
Soil Salinization
Cleanup
Prevention
Reduce irrigation
Flush soil (expensive and wastes water)
Stop growing crops for 25 years
Switch to salt-tolerant crops (such as barley,
cotton, sugarbeet)
Install underground drainage systems (expensive)
Fig. 13-15, p. 281
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Salinization and Waterlogging of Soils A
Downside of Irrigation

• Example of high evaporation, poor drainage, and
  severe salinization.
• White alkaline salts have displaced crops.

Figure 13-14
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INCREASE SOIL QUALITY AND CROP YIELDS BY

• Modern farm machinery can plant crops without
  disturbing soil (no-till and minimum tillage).
• Conservation-tillage farming
• Increases crop yield.
• Raises soil carbon content.
• Lowers water use.
• Lowers pesticides.
• Uses less tractor fuel.
• Downside-expensive machinery

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INCREASE SOIL QUALITY AND CROP YIELDS BY

• Fertilizers can help restore soil nutrients, but
  runoff of inorganic fertilizers can cause water
  pollution.
• Organic fertilizers from plant and animal
  (fresh, manure, or compost) materials.
• Commercial inorganic fertilizers Active
  ingredients contain nitrogen, phosphorous, and
  potassium and other trace nutrients.
• PLANT COVER CROPS
• WINDBREAKS, ROTATE CROPS

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What is the green revolution?

• High input agriculture and produces more food per
  unit of land.
• Use of pesticides
• Use of irrigation
• Use of fertilizers
• Growing monocultures of genetically engineered
  plants
• Keep ground covered all year long with different
  plants

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THE GREEN REVOLUTION AND ITS ENVIRONMENTAL IMPACT

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

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

• The ideal pest-killing chemical has these
  qualities
• Kill only target pest.
• Not cause genetic resistance in the target
  organism.
• Disappear or break down into harmless chemicals
  after doing its job.
• Be more cost-effective than doing nothing.

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Pesticide Protection Laws in the U.S.

• Government regulation has banned a number of
  harmful pesticides (DDT).
• The Environmental Protection Agency (EPA), the
  Department of Agriculture (USDA), and the Food
  and Drug Administration (FDA) regulate the sales
  of pesticides under the Federal Insecticide,
  Fungicide and Rodenticide Act (FIFRA).

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PROTECTING FOOD RESOURCES PEST MANAGEMENT

• Advantages and disadvantages of conventional
  chemical pesticides.

Figure 13-28
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Integrated Pest Management

• Using a combination of BIOLOGICAL, CHEMICAL, AND
  PHYSICAL pest management.
• Lower the use of pesticides
• Reduce pest populations

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BIOLOGICAL METHODS

• Introduce predators
• Create habitats for predators
• Introduce parasites
• Introduce disease-carrying bacteria
• Introduce sterile males to lower reproductive
  success
• Genetically modified plants that resist pests

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CHEMICAL METHODS

• Use pheromones to attract pests to traps
• Spray crops with hot water to scald pests
• Use less persistent pesticides
• Spray crops with soap solution

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PHYSICAL METHODS

• Noise to repel pests
• Physical barriers
• Statues, scarecrows, etc.

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Sustainable Agriculture

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

Figure 13-34
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What Can You Do?
Reducing Exposure to Pesticides
Grow some of your food using organic methods.
Buy organic food.
Wash and scrub all fresh fruits, vegetables,
and wild foods you pick.
Eat less or no meat.
Trim the fat from meat.
Fig. 13-30, p. 299
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THE GENE REVOLUTION

• Selective Breeding (Take along time, only mix
  similar species, not long before pests wipe out)
• Artificial selection is breeding two similar
  organisms such as two types of corn or tomatoes
  to improve the quality of the food.
• Cross breeding is breeding two different species.
• Genetic engineering FASTER!!

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What is gene splicing and how does it lead to
recombinant DNA?

• http//www.youtube.com/watch?vuQ9M-r1dXcE

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Mixing Genes

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

Figure 13-19
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THE GENE REVOLUTION

• GMOs could be grown to help reduce malnutrition,
  reduce use of large amounts of inorganic
  fertilizers, use less water, grow faster and
  larger, etc.

Figure 13-20
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Problems with the gene revolution

• Controversy has arisen over the use of
  genetically modified food (GMF).
• We know too little about the long-term potential
  harm to human and ecosystem health.
• Controversy over legal ownership of genetically
  modified crop varieties and whether GMFs should
  be labeled.
• Could create herbicide resistant plants
• Could create new allergies
• Should a seed company have the legal right to sue
  a farmer for using a second year seed?

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• Can GM foods save the world?

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PRODUCING MORE MEAT

• About half of the worlds meat is produced by
  livestock grazing on grass.
• The other half is produced under factory-like
  conditions (feedlots).
• Densely packed livestock are fed grain or fish
  meal.
• Antibiotic injections, hormone injections
• Why would eating more farm raised fish and
  chicken reduce environmental affects?
• Which animals convert grain to biomass faster?
  Food Chain!!

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

• Government subsidies given to the fishing
  industry are a major cause of overfishing.
• Subsidies are not taken away because fishing
  industry would suffer and many would lose jobs.
• Redirect money toward new jobs in fishing
  industry.
• Marine Stewardship Council (MSC)- sustainable
  fishing seal
• 3 ways to sustain fisheries
• Quotas
• Reserves
• Regulating gear and methods
• Limiting the number of fishing boats

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Aquaculture Aquatic Feedlots

• Raising large numbers of fish and shellfish in
  ponds and cages is worlds fastest growing type
  of food production.
• Fish farming involves cultivating fish in a
  controlled environment and harvesting them in
  captivity.
• Fish ranching involves growing specific species
  that live part of their lives in freshwater and
  part in saltwater.
• Fish are held for the first few years, released,
  and then harvested when they return to spawn.

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Aquaculture

• Aquaculture species Seaweeds, mussels, oysters,
  mollusks, shrimp, salmon, trout, catfish
• For aquaculture to be profitable it must be
  marketable, inexpensive to raise, efficient at
  converting feed to biomass, grow quickly, and
  disease resistant
• Downsides it takes away natural habitats, water
  wastes, accidental release of non-native species,
  transmission of diseases into the wild

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

• Governments use three main approaches to
  influence food production
• Control prices to keep prices artificially low.
• Provide subsidies to keep farmers in business.
• Let the marketplace decide rather that
  implementing price controls.

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Solutions Steps Toward More Sustainable Food
Production

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