Transcript Food Resources: A Challenge For Agriculture

Food Resources: A Challenge For
Agriculture
Kwashiorkor is a virulent form of childhood malnutrition
characterized by edema, irritability, anorexia, ulcerating
dermatoses, and an enlarged liver with fatty infiltrates. The
presence of edema caused by poor nutrition defines
kwashiorkor.[1] The cause of kwashiorkor was thought to be
due to insufficient protein consumption alone, however
micronutrient and antioxidant deficiencies are now
believed to play important roles.
Overview
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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
Human Foods
Food and Nutrition
•
Carbohydrates
– Sugars and starches metabolized by cellular respiration to produce energy (in the form of
ATP)
•
Proteins
– Large, complex molecules composed of amino acids that perform critical roles in
body (hair nails and muscles are made of protein)
– There are 20 different amino acids required for human nutrition.
– The Human can synthesize 10-11 of these on it’s own
– Humans lack the ability to synthesize the other aa’s called “essential amino acids”
– They are Isoleucine, leucine, lysine, methionine, phenyalanine, threonine,
tryptophan, valine, histadine, and, in children arginine
•
Lipids
– Include fats and oils and are metabolized by cellular respiration to produce energy
•
Vitamins (help regulate metabolism)and Minerals (ingested in the form of salts dissolved in water)
World Food Problems
• Feeding growing population is difficult
• Annual grain production (left) has increased since 1970
• Grain per person has not (right)
The answer
lies in
controllingh
uman
population
growth
World Food Problems
• Famine
– Failure of crops caused by drought, flood or
catastrophic event
– Temporary but severe shortage of food (Africa, Asia, and
Latin America most at risk)
– Worst = African Famine 1983-85 Etiopia hit hardest)
• Maintaining World Grain Carryover Stockpiles
– 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
• Why the decline?
– Rising temperatures
– Falling water tables and
droughts
– Ethanol production
– More grain is going
towards feeding
livestock as more people
eat meat especially in
China as their incomes
rise ***see table 18-1 p.413
World Food Problems
• Poverty and Food
– 1.3 billion people are so poor they cannot afford
proper nutrition
– More common in
• Rural than urban areas
• Infants, children and the elderly
• Economics and Politics
– Cost money to store, produce, transport and
distribute food
– Getting food to those who need it is political (some
dishonest politicians sell food instead of giving it to the hungry)
Principle Types of Agriculture
Industrialized
agriculture
– Modern
agriculture
methods that
require large
capital input,
and less land
and labor
Principle Types of Agriculture
• Subsistence Agriculture
– Traditional agricultural methods, which are
dependent on labor and large amounts of land
• Examples:
– Shifting cultivation
– Slash and burn agriculture
– Nomadic herding
– Intercropping
– See mini-glossary pg.417
Challenges of Producing More Crop and
Livestock
• Domestication and Genetic Diversity
– Domestication of crops and livestock causes a loss
of genetic diversity
• Farmer selects and propagates animals with desirable
agricultural characteristics
•
•
Many high yielding
crops are genetically
uniform
High likelihood that
bacteria, fungi, viruses,
etc. will attack and
destroy entire crop
Dutch Belted Cow now very rare in Netherlands where it
originated
Challenges of Producing More Crop and
Livestock
• Increasing Crop Yield
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•
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Food production
increased in
developed
countries (wheat
(left)
Pesticides
Selective
breeding
Green Revolution
• The production of more food per acre of
cropland by using modern cultivation
methods, and the new high yielding varieties
of crops
• Norman Borlaug 1940-1950’s credited with
the start of G.R.
• Worked with wheat
• Awarded Nobel Prize in 1970 for his work
Problems with the Green Revolution
• Critics argue that developing countries now
rely on imported technologies
• High energy costs associated with the higher
crop yields (requires fossil fuels)
• Environmental problems associated with
inorganic fertilizers and pesticides
Case-In-Point Green Revolution
• High Yielding Rice Varieties
Traditional(a);High yield dwarf variety(b); very high yield,
dwarf-thick stock variety(c)
Challenges of Producing More Crop and
Livestock
• Increasing Livestock Yields
– Hormone supplements
• US and Canada do this
• Europe does not citing human health concerns
• Studies have shown that hormones could cause cancer
– Antibiotics
• 40% of antibiotics produced in US are used in livestock
operations
• Gain 4-5% more weight with antibiotics
• Problems with increased bacteria resistance (MRSA)
Antibiotic Use and Resistance
Environmental Impacts of Agriculture
• High use of fossil fuels and
pesticides
– Air pollution
• Untreated animal wastes and
agricultural chemicals
– Water pollution
– Harms fisheries
• Insects, weeds, and disease-causing
organisms developing resistance to
pesticides
– Contaminate food supply
Colorado Potato Beetle has become resistant to most pesticides
that are used
Environmental Impact of Agriculture
• Land degradation
– Decreases future ability of land to support crops
or livestock
• Habitat fragmentation
– Breakup of large areas of habitat into small,
isolated patches
• Cultivating marginal lands
– Irrigating dry land
– Cultivating land prone to erosion
Solutions to Agricultural ProblemsSustainable Agriculture
Sustainable Agriculture
• Examples:
– Natural Predator-prey relationships instead of
pesticides (lady bug and aphids)
– Crop selection (insect resistant varieties)
– Crop rotation and conservation tillage
– Supplying nitrogen with legumes
– Organic agriculture
• Integrated Pest Management (IPM)
– Limited use of pesticides with sustainable
agriculture practices
Genetic Engineering
• 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)
• Determined to be safe for human
consumption
• Concerns about GMO seed or pollen
spreading in wild
. Monarch Butterfly/Super Weeds
• Backlash against GMOs
• GMOs are not currently labeled
– FDA finds it would be counterproductive and
expensive to label
Fisheries of the World- Problems
• Ocean Pollution - dumping ground
– Oil
– Heavy metals
– Deliberate litter dumping
– Stormwater runoff from cities and agricultural
areas
• Aquaculture
– Growing of aquatic organisms for human
consumption
– Great potential to supply food
Fisheries of the World- Problems
MR PLATT, OVERHARVESTING COD IN ALASKA
• No nation lays claim to
open ocean
– Resource susceptible to
overuse and degradation
• Overharvesting
– 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
• Overharvesting
(continued)
– Sophisticated
fishing equipment
– Bycatch killed off
– Magnuson
Fisheries
Conservation Act
Fisheries of the World- Problems
• Aquaculture (continued)
– Locations of fisheries may hurt natural habitats (removing mangroves
for shrimp)
– Produce waste that pollutes adjacent water (lots of fish waste in a
relatively small area)
Aqualture used
for shrimp is
the single
largest factor
responsible for
mangrove
habitat loss