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Chapter 19
Food Resources: A Challenge For
Agriculture
Overview of Chapter 19
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Food and Nutrition
World Food Problems
Principle Types of Agriculture
Challenges of Producing More Crops and
Livestock
Environmental Impact of Agriculture
Solutions to Agricultural Problems
Fisheries of the World
Food and Nutrition
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Carbohydrates
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Proteins
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Large, complex molecules composed of amino
acids that perform critical roles in body
Lipids
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Sugars and starches metabolized by cellular
respiration to produce energy
Include fats and oils and are metabolized by
cellular respiration to produce energy
Vitamins and Minerals
Human Foods
World Food Problems
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Feeding growing population is difficult
Annual grain production (left) has increased since
1970
Grain per person has not (right)
World Food Problems
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Famine
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Failure of crops caused by drought, flood or
catastrophic event
Temporary but severe shortage of food
Maintaining World Grain Carryover
Stockpiles
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Amounts of rice, wheat, corn and other grains
remaining from previous harvest
Provides measure of food security
Decreased each year since 1987
UN feels carryover stock should not fall below
70 days
World Grain
Carryover Stock
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Why the decline?
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Rising
temperatures
Falling water tables
and droughts
Ethanol production
More grain is going
towards feeding
livestock
World Food Problems
Already read in text book that major food-producing countries
produce enough grain to feed the rest of the world.
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So why are people hungry?
Poverty - 1.3 billion people are so poor they
cannot afford proper nutrition
• poverty increasing in developing countries
• rural areas poorer than urban areas
• infants, children and the elderly most at risk
unequal distribution of available food supplies
loss of or decline in arable land
increasing rate of population growth
• population growth control would ease food
related problems (more in next unit)
World Food Problems
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Economics
• costs money to produce, store, transport, and
distribute food
• countries (usu. developing countries) with the
greatest need for food cannot afford to pay
for it
• food-producing nations (usu. developed countries)
cannot afford to give it away
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Politics
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corruption, greed, power
Developing countries need to become agriculturally
self-sufficient
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Principle Types of Agriculture
o Industrialized Agriculture
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relies on high inputs of capital ($) and energy
requires less land and labor
produces high yields through monoculture
land degradation
air pollution – use of fossil fuels and pesticides
surface water and groundwater pollution by
manure from CAFOs (livestock factories)
eutrophication -fertilizer enrichment of surface water
pesticide resistance in many insect, weeds, and
disease-causing organisms
habitat fragmentation by clearing grasslands &
forests, and draining wetlands to grow crops
Principle Types of Agriculture
o Subsistence Agriculture
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Traditional agricultural methods, which are
dependent on labor and large amounts of
land
Examples:
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Shifting cultivation
Slash and burn agriculture
Nomadic herding
Intercropping
Principle Types of Agriculture
o Sustainable Agriculture
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alternative or low-input agriculture
combination of methods best suited to problems
maintain soil fertility – crop rotation (nitrogen)
control soil erosion - conservation tillage, and
contour plowing
increase biological diversity
organic fertilizers - compost and manure
conserve of water and energy
Principle Types of Agriculture
o Sustainable Agriculture
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integrated pest management (IPM)
• natural predator-prey relationships to
control pests
• limited use of pesticides only when necessary
Solutions to Agricultural ProblemsSustainable Agriculture
Challenges of Producing More Crop and Livestock
o Domestication and Genetic Diversity
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Domestication of crops and livestock
Farmer selects and propagates animals with
desirable agricultural characteristics
• Benefit: development of high yielding crops or
high producing livestock (meat and milk)
• Drawback: loss of genetic diversity - Many high
yielding crops are genetically uniform
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High likelihood that if
bacteria, fungi, viruses,
etc. attack, will destroy
entire crop.
Why?
Challenges of Producing More Crop and
Livestock
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Increasing Crop Yield
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Food production
increased in
developed
countries (wheat
(left)
Pesticides
Selective
breeding
Case-In-Point Green Revolution
Increasing Crop Yields
What was the green revolution?
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using modern cultivation methods, such as
inorganic chemical fertilizer and
pesticides, and the high-yielding varieties
of certain staple crops to produce more
food per acre of cropland
Selective Breeding
Case-In-Point Green Revolution
High Yielding Rice Varieties
Challenges of Producing More Crop and
Livestock
o Increasing Livestock
• Hormone supplements
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Yields
US and Canada do this
Europe does not citing human health concerns
Antibiotics
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40% of antibiotics produced in US are used
in livestock operations
Problems with increased bacteria resistance
Antibiotic Use and Resistance
Genetic Engineering
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Manipulation of genes by taking specific gene from a cell of
one species and placing it into the cell of an unrelated species
Issue with Genetically Modified
Organisms (GMOs)
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Determined to be safe for human
consumption
Concerns about GMO seed or pollen
spreading in wild
Backlash against GMOs
GMOs are not currently labeled
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FDA finds it would be counterproductive and
expensive to label
Environmental Impacts of Agriculture
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High use of fossil fuels and
pesticides
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Untreated animal wastes and
agricultural chemicals
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Air pollution
Water pollution
Harms fisheries
Insects, weeds, and diseasecausing organisms developing
resistance to pesticides
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Contaminate food supply
Environmental Impact of all kinds of
Agriculture
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Land degradation
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Habitat fragmentation
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Decreases future ability of land to support
crops or livestock
Breakup of large areas of habitat into small,
isolated patches
Cultivating marginal lands
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Irrigating dry land
Cultivating land prone to erosion
Fisheries of the World- Problems
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No nation lays claim to open
ocean
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Resource susceptible to
overuse and degradation
Tragedy of the Commons
Overharvesting
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Many species are at point of
severe depletion
Cod (right)
62% of world’s fish stock are
in need of management action
Fisheries of the World- Problems
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Overharvesting
due to
sophisticated
fishing equipment
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Bycatch killed
off because often
illegal to take
from ocean
Fisheries of the World- Problems
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Ocean Pollution – degradation of marine
environments
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oceans used as dumping grounds
old saying: “dilution is the solution to pollution”
oil
heavy metals (such as …)
litter - deliberate dumping
stormwater runoff from cities and agricultural
areas
Fisheries of the World- Problems
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Aquaculture
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growing of aquatic organisms for human
consumption
both fresh and marine waters
great potential to supply food
locations of fisheries may degrade natural
habitats
produce waste that pollutes adjacent water
use of antibiotics in feed
spread of disease and sea lice due to close
quarters
Aquaculture