Transcript Ch. 15 Food and Agriculture

Food and Agriculture
Chapter 15
Ethiopia
 In 1985, there was a lack of rain, loss of
soil, and a great war
 Caused the crops to fail
 Created a famine
 Widespread starvation caused by a
shortage of food
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Malnutrition
 A condition that occurs when people do
not consume enough Calories
 If only eat wheat and rice, lack protein
 Amino acid deficiency
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Food Efficiency
 Measure of the quality of food produced
on a given area of land with:
 Limited inputs of energy
 Limited inputs of resources
 Desire a large amount of crops with the
least negative inpact on environment
World Food Problems
 Unequal distribution of food
 Drought
 Famine
Drought
 Can lead to famine
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Green Revolution
 Between 1950 and 1970
 Brought about a great deal of new crops with
a higher yield
 Requires large amounts of water, fertilizer,
pesticides, machinery, irrigation
 Was this good?
 Was like bringing a Walmart into a community
Green Revolution
* Led to new crop varieties, increased
yields
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Subsistence Farming
 Grows only enough food for local use
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Arable Land
 Land that can be used to grow crops
 Fertile soil can support healthy plants
 Roots grow in topsoil
Top Soil
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 Temperature changes and moisture
causing rocks to crack
 Chemical weathering - minerals that
react with water
 Earthworms and insects
 Earthworms are good indicators
Erosion
 The weathering away of rock or soil by
wind and water
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Land Degradation
 Use to be able to plant on land and
then leave it alone for several years to
gain more nutrients
 What happened when the populations
increased?
Desertification
 Decreases the amount of arable land
available
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Soil Conservation
 Soil retaining terraces
 Countour plowing
 Plowing across a hill instead of up and
down
 No-till farming
Soil Conservation
 Includes measures that prevent
downhill erosion
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No-Till Farming
 Causes Less Erosion
Enriching the Soil
 Compost Piles
 Return nature to nature
 City compost piles?
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Salinization
 Accumulation of salts in the soil
 In areas like California and Arizona
 Why do you think these places?
 Water comes from rivers and streams,
not rain water
Pest Control
 Pesticides
 Biological Pest Control
 Integrated Pest Management
 Engineering a Better Crop
 Sustainable Agriculture
Pesticides
 Pesticide Resistance
 Human Health Concerns
 Pollution and Persistence (pesticides
that don’t break down quickly)
Biological Pest Control
 Pathogens - good and bad
 Plant defense - resistant to fungi
 Chemicals from Plants - chemicals from
chrysanthemums - pesticides
Disrupting Insect Breeding
 Growth regulators - interfere with a
stage of a pest’s life
 Pheromones - confuse moths with
mating habits
Integrated Pest Management
 Aims to reduce pests with minimal
economic damage
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Genetic Engineering
 Transfers desirable traits
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Animal Domestication
 Over harvesting
 Aquaculture
 Livestock
Livestock
 Ruminants - cattle, sheep, goats
 Cud-chewing mammals that have three
or four chambered stomachs
 Poultry
Overharvesting
 Depletes fish populations
Poverty
 Plays a large role in determining the
occurrence of malnutrition
 All of these contribute directly to fertile
topsoil except:
 Bedrock chemical reactions
 Minerals supplied by rock particles
 Decomposition action of fungi and
bacteria
 Earthworm’s breaking down the soil
 Many people worldwide are
malnourished, in part because food
production is:
 Sufficient, but distribution is
inconsistent
 Which of the following agricultural
products require the least amount of
energy?
 Wheat or cows?
 Traditional agriculture typically depends
upon
 Manual or animal plowing
 Organic fertilizers
 All of these are environmental problems
associated with pesticide use in the U.S.
except
 The ongoing application of DDT
 Human health concerns
 Pesticide persistence
 Pesticide resistance
 One potential way to deal with the
problem of over harvesting is
intensifying
 Aquaculture
 Products obtained from livestock include
 Leather, wool, eggs, meat, and manure
 Erosion is most likely when the soil is:
 Bare and exposed to wind and rain
 Salinization may be caused by:
 Long-term irrigation
 Earth’s available arable land is being
reduced by
 Fast-growing human populations
 Soil erosion
 desertification