ch. 18-food and agriculture

Food and Nutrition
World Food Problems
Principle Types of Agriculture
Challenges of Producing More Crops and
Environmental Impact of Agriculture
Solutions to Agricultural Problems
Fisheries of the World
 Sugars and starches metabolized by cellular
respiration to produce energy
 Large, complex molecules composed of amino
acids that perform critical roles in body. Must
get essential amino acids from food.
 Include fats and oils and are metabolized by
cellular respiration to produce energy. Most
Vitamins (molecule) and Minerals (elements
– iron, calcium)
Annual grain production (left) has increased
since 1970
Grain per person has not (right)
South Asia and Sub-Saharan Africa
 Growing population
 Rising temperatures
 Falling water tables
and droughts
 Ethanol production
 More grain is going
towards feeding
▪ Ex: 1 kg of beef
requires 7 kg grain
More sustainable land
Harder to get
essential amino acids
Rice and beans = nutritious
Just rice = not nutritious
Easy source of protein
– meat, milk, eggs
 Livestock requires
more land, more
energy, more water
 Risk of heart disease
Poverty and Food
 1.3 billion people are so poor they cannot
afford proper nutrition
 Undernourished vs. malnourished
▪ Kwashiokor – protein deficient
 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
Industrialized agriculture
High yields
Fossil fuels:
Subsistence Agriculture
 Low yields (enough for family)
 Energy from humans/work animals
 Require lots of land
 Shifting cultivation
 Slash and burn agriculture (deforestation)
 Nomadic herding
 No pesticides, synthetic fertilizers
genetically modified crops
 causes a loss of genetic diversity
▪ Farmer selects and propagates
plants/animals with desirable agricultural
• Many high yielding
crops are genetically
• High likelihood that
bacteria, fungi, viruses,
etc. will attack and
destroy entire crop
Increasing Crop Yield
Graph = wheat
• fertilizers
• Pesticides
• Selective
1960s – more grain (wheat/rice) per
Selective breeding
Use of fertilizers and irrigation made
it possible to grow crops in more
Started in Mexico, spread to US,
India, China
 High energy costs
▪ Require fossil fuels to make fertilizers,
build/run tractors, construct dams/canals,
pump water from groundwater
 Environmental degradation due to
inorganic fertilizers and pesticides
 Led to overpopulation
CAFOs (concentrated animal feeding operations): less
land, but more antibiotics. Waste disposal
Increasing Livestock Yields:
 Antibiotics
▪ Problems with increased bacteria resistance
 Hormone supplements (rBGH)
▪ US and Canada do this: increase growth and milk
▪ Europe does not citing human health concerns
(Precautionary Principle)
High use of fossil fuels
 Air pollution
Untreated animal wastes
and agricultural chemicals
 Water pollution
 Harms fisheries
Insects, weeds, and
disease-causing organisms
developing resistance to
 Contaminate food supply
 Kills beneficial soil organisms
Land degradation
 Decreases future ability of land to support
crops or livestock
▪ Erosion – decreases soil fertility, sediments
pollute water
▪ Compacting soil, waterlogging, salinization
Habitat fragmentation, deforestation
 habitat loss
 erosion
 Decreases biodiversity and gene pool
marginal lands
 Irrigating dry land
 Cultivating land
prone to erosion
 Ex: Ogallala Aquifer
= nonrenewable
resource b/c water
so old
 Drip irrigation!
 Pest control: natural Predator-prey
relationships instead of pesticides, crop
 Reduce erosion: conservation tillage and
contour plowing
 Reduce fertilizers – crop rotation, animal
manure, supplying nitrogen with
Integrated Pest Management (IPM)
 Limited use of pesticides by using
knowledge of the life cycles of pests,
pheromones, trapping, and then
targeted pesticide use;
allowing some pests is fine
Organic agriculture
 No pesticides, synthetic fertilizers
genetically modified crops
4 – I can cite at least 2 methods for
each of the farming issues below
3 – I can cite at least 1 method to
farm sustainably for each of the
following farming issues: pesticides,
synthetic fertilizers, erosion, soil
salinization, water consumption
2 - I know a few examples, but not
one for each issue.
1 – I know what sustainable means.
Transferring genes of desirable trains from
one organism into the DNA of another
Faster than selective breeding
1st GM food on market – Flavr Savr
Typical goals
 Increase nutrition – ex: golden rice
 Pest resistance – ex: Bt corn
 Resistant to other environmental stress
– drought, salty or acidic soils
GE in animals
 Create hormones to increase growth
Determined safe by FDA
Concerns: allergies, reduced
biodiversity if introduced to wild
Labeling: none in US
4 – I can explain the pros and cons
of GE food.
3 – I understand multiple reasons
why GE food is developed AND
multiple reasons why people are
concerned about it.
2 - I understand either why GE food
is developed or why people are
concerned about it, but not both.
1 – I know what GE food is.
No nation lays claim
to open ocean
 susceptible to overuse
 Tragedy of the
 Many species are at point
of severe depletion
 Food for growing human
 Technological advances in
fishing gear
Longlines –
thousands of hooks
Purse-sein nets
Trawl net – dragged
along the bottom
Spotter airplanes
• Overfishing reduces gene
pool of existing fish
• By-catch DIE
 Magnuson-Stevens Fishery Conservation
and Management Act
▪ EX: Set quotas, limits # of boats
• Marine
Ocean Pollution - dumping ground
 Oil
 Heavy metals
 Deliberate litter dumping
 Stormwater runoff from cities and
agricultural areas – biggest pollution
 Coastal areas degraded by development (many
fish depend on tidal marshes, mangrove
swamps, estuaries for spawning and feeding)
 Raising of aquatic organisms for human food
 Protein!!
 Negatives:
▪ Locations of fisheries may hurt natural habitats –
compete for shore space, destroy mangroves, destroy
breeding grounds for fish
▪ Produce waste that pollutes adjacent water
▪ Often fed fish from the wild
▪ Expensive facility
▪ Easy spread of disease  antibiotics
4 – I can teach the next class.
3 – I understand at least 2 fishing
techniques that may lead to
overfishing, the laws that serve to
protect fisheries, and the pros and
cons of aquaculture.
2 – I understand but need to re-read
my notes.
1 – I know why overfishing is bad.