Food and Agriculture

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Food and Agriculture
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History and Types of Agriculture

• Demand-based agriculture - production determined
  by economic demand and limited by classical
  economic supply and demand theory. This approach
  became common during the industrial revolution.
• Resource-based agriculture - production
  determined by resource availability economic
  demand usually exceeds production. This approach
  was the original type of farming 10,000 years
  ago. Modern approaches are very high tech and
  somewhat more expensive.

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Plant Food Sources

• 250,000 plant species Þ
• 3000 tried as crops Þ
• 300 grown for food Þ
• 100 species used on large scale for food Þ
• 15 to 20 species provide vast majority (90) of
  mans food needs
• It takes about 16 pounds of grain to produce one
  pound of edible meat
• Largest crop volumes provided by wheat, rice,
  corn, potatoes, barley
• Wheat and rice supply 60 of human caloric
  intake

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Other Plant Food Sources

1. Potatoes
2. Barley
3. Sweet Potato
4. Cassava (source of tapioca)
5. Grape
6. Soybean
7. Oats
8. Sorghum
9. Sugarcane

1. Peanut
2. Watermelon
3. Cabbage
4. Onion
5. Bean
6. Pea
7. Sunflower Seed
8. Mango

1. Millet
2. Banana
3. Tomato
4. Sugar Beet
5. Rye
6. Orange
7. Coconut
8. Cottonseed
9. Apple
10. Yam

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Types of Crops

• Cash crops vs. subsistence crops
• cash crops may provide non-food products (latex)
  or provide products which do not make up our
  primary nutrition (tea, coffee)

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Agroecosystems

• Ecosystem created by agricultural practices
• characterized by low
• Genetic diversity
• Species diversity
• Habitat diversity

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Agroecosystems

• Agroecosystems differ from natural ecosystems in
  five major ways
• Farming attempts to stop ecological succession
• Species diversity is low because farmers usually
  practice monoculture. Monoculture tends to ß
  soil fertility
• Farmers plant species (crops) in an orderly
  fashion - this can make pest control more
  difficult
• Food chains are far more simple in agroecosystems
  because of pest control and other farming
  practices
• Plowing is like no other natural disturbance -
  plowing can Ý erosion and cause more nutrient
  loss (which is replaced by fertilizer)

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Are world food supply and the environment related?

• Our current food problem is the result of our
  human population
• Food production depends upon favorable
  environmental conditions
• Agriculture changes the environment - such
  changes can be detrimental
• Food supply can be adversely affected by social
  unrest that influence agriculture

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Grain Production

• Grain production increased from 631 to 1780
  million metric tons from 1950 to 1990.
• Has leveled off since then
• Top five countries in order of producing the most
  amount of grain are
• China
• United States
• India
• Canada
• Ukraine

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Livestock

• domesticated livestock (sheep, pigs, chickens,
  cattle) are an important food source for humans
• ruminants (four-chambered stomachs) contain
  bacteria that can convert plant tissue to animal
  protein/fat Þ hence, plant material originally
  unusable for man is converted into food sources
  that can be ingested by man

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Wilkes, Angela. My first word board book. (1999)
DK Publishing, NY.
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Meat Sources

• About 90 of all meat and milk are consumed by
  United States, Europe and Japan which constitute
  only 20 of world population
• About 90 of the grain grown in the United States
  is used for animal feed
• 16 kg of grain Þ 1 kg of meat
• By eating grain instead would get 20 times the
  calories and 8 times the protein

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Malnutrition and Famines

• One quarter of the human population is
  malnourished
• Sub-Saharan Africa (225 million)
• East and Southeast Asia (275 million)
• South Asia (250 million)
• Parts of Latin America

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Malnutrition/Famines

• Stem from not enough calories per day in addition
  to not getting the necessary amounts of
  carbohydrates, proteins, lipids (fats), minerals,
  and vitamins
• Generally diets are high in starches
• Famine conditions
• Major droughts -- Political instability
• Population sizes -- Land Seizures
• Massive immigration -- Pestilence
• Floods -- Distribution breakdown
• Wars --Panic buying
• Chaos in economy -- Hoarding

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Limits on Food Production

• arable land
• precipitation
• temperature
• global warming (ice age temp was only 5o C less
  than now!)

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Methods to Increase Food Supply

• Improved irrigation and utilization of water
• Drip irrigation
• Increasing arable land
• Difficult because of precipitation and
  temperature
• Eating lower on the food chain
• Most rangeland is not arable and humans cannot
  utilize grass/hay as food therefore, this
  argument is not considered valid

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Methods to Increase Food Supply

• Food distribution modification
• Today distribution of food is a major problem in
  Africa/Asia
• Best solution teach locals how to best utilize
  their land with appropriate technology so they
  can attempt to support themselves and not rely on
  others.

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New vs. Old Agriculture
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Soil Resources

• What is Soil?
• Ways We Use and Abuse Soil
• Erosion

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How much Land is Arable?
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Pests and Pesticides
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The problem with chemicals

• Groundwater contamination
• Effects of low concentrations?
• Bioaccumulation and Biomagnification

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Pesticides Pro and Con

• Kill unwanted pests that carry disease (rats,
  mosquitoes, Tse-Tse flies)
• Increase food supplies
• More food means food is less expensive
• Effective and fast-acting
• Newer pesticides are safer, more specific
• Reduces labor costs on farms
• Food looks better
• Agriculture is more profitable

• Accumulate in food chain
• Pests develop resistance 500 species so far
• Resistance creates pesticide treadmill
• Estimates are 5-10 in damage done for 1 spent
  on pesticide
• Pesticide runoff
• Destroy bees - 200 million
• Threaten endangered species
• Affect egg shell of birds
• 5 actually reach pest
• 20,000 human deaths/year

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Types of Pesticides

• Biological Ladybugs, parasitic wasps, etc.
• Carbamates effect nervous system of pests more
  water soluble than chlorinated hydrocarbons
• Aldicarb, aminocarb, carbaryl (Sevin),
  carbofuran, Mirex
• Chlorinated Hydrocarbons affect nervous system
• Aldrin, Chlordane, DDT, dieldrin, lindane and
  paradichlorobenzene
• Fumigants are used to sterilize soil and prevent
  grain infestation

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Types of Pesticides

• Inorganic arsenic, copper, lead, mercury
• Highly toxic and bioaccumulation
• Organic or natural derived from plants such as
  tobacco and chrysanthemum
• Organophosphates extremely toxic, low
  persistence
• Malathion, parthion, chlophyrifos, acepate,
  propetamphos and trichlofon

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Alternatives to Pesticides

• Polyculture instead of monoculture
• Intercropping alternate rows of crops that have
  different pests
• Planting pest-repellent crops
• Mulch to control weeds
• Natural insect predators ladybugs, preying
  mantis, birds
• Rotating crops to disrupt insect cycles
• Using Pheromones to attract insects to traps
• Releasing sterilized insects