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Transcript
Food & Agriculture
Chapters 11 & 12
APES
2012
Questions to ponder
How can we feed a world population of 9
billion?
 What advancements in technology and
agriculture need to occur in the next 50
yrs?
 Exactly what is organic food, industrial
farming, and genetically modified foods?
 Why should I care?

Watch for the following buzz
words!!
Overnourished
 Undernourished
 Malnourished

– Kwashiorkor
– Marasmus
Is there enough food?
As population has increased, our food supply has
increased.
 There is enough food for everyone but it is not
distributed equally.
 We in US are overnourished- consume too many calories
 Some countries have overcome food shortfalls

– EX: Indonesia used to largest importer of rice, now they are the
biggest producers of rice.
– Why? irrigation, fertilizers, pesticides, use high yielding crop
varieties of rice.

Other countries are still undernourished (don’t get
enough calories)
– Sub-Saharan Africa- drought, war, governmental
mismanagement have kept people starving in poverty.


In developing countries,
800 million people are
chronically hungry. 200
million of them are kids
Undernourishment during
childhood results in
– Stunted growth
– Mental retardation
– Social/developmental
disorders

Undernourished more
susceptible to infectious
disease & diarrhea.
Food Security
Poverty is the greatest threat to food
security- ability to get food everyday.
 1.4 billion that live on $1/day can’t buy
food or have no means to grow it for
themselves.
 In many families the males get largest &
most nutritious share- females & kids have
poorest diet.

Malnourishment





Not only need calories, but also
specific nutrients
Malnourished- lack of necessary
nutrients (protein, vitamins, minerals)
Kwashiorkor- protein deficiency but
has enuf calories; reddish/orange hair,
discolored skin, swollen belly,
susceptible to infectious disease
Marasmus- diet low in calories &
protein; thin, shriveled, susceptible to
infectious disease
Most countries eat maize (corn), rice,
manioc (tapioca) but these food lack
essential vitamins like…
–
–
–
–
Folic acid (for fetal brain development)
Vitamin A (for good vision)
Iron (for strong blood)
Iodine (for making of thyroxine- which
regulates metabolism & brain fxn)
Quick write!

Identify GM Food that will alleviate one of
the previous diseases caused by
malnourishment.
Famine

http://www.cnn.co
m/2011/WORLD/af
rica/07/20/iyw.how
tohelp.somalia.fami
ne/index.html
Famine



Large-scale food shortages,
massive starvation, social
disruption, economic chaos
Usually mass migrations to
refugee camps in search of
food & medical care
Can be caused by…
– Environmental conditionsdrought, insect infestations
– Politics & War- political
boundaries can prevent
people from following
traditional routes to flee
environmental disaster
What you need to be healthy…
Major Crops




Wheat & rice are staple
foods for 5 billion people
in developing countries.
In mountainous areaspotatoes, barley, oats &
rye (N. Europe, N. Asia)
In warm, wet areascassava, sweet potatoes,
roots/tubers (Amazonia,
Africa)
In dry regions- Millet &
sorghum (Africa)
Meat, Milk, Poultry



N. America, Europe,
Japan make up 20% of
world population. We
consume 80% of milk &
meat.
LDC have 80% of
population, raise 60% of
meat, but consume only
20% of that meat. Most
is exported.
90% of N. American grain
is used to feed livestock.
What a waste of energy!
CAFOs
Concentrated
animal Feeding
Operations Large
indoor/outdoor
structures
designed for max
output.

Meat vs. Grain



Every 20 kg of grain fed
to cows produces 1 kg of
edible meat.
The other 19 kg are used
by the animal for energy.
If we ate grain directly,
we would get 21x more
calories & 8x more
protein than by eating the
meat it produced.
Fish & Seafood






Important source of protein in many
countries
Oceans & major rivers are
overharvested or habitats are
destroyed
Radar, sonar, remote sensing, GPS,
longlines with 60,000 hooks, trawl nets
large enough to engulf a jumbo jet,
make it possible to exhaust entire
populations in just a few years.
1 in 4 animals caught in nets are “bycatch” or non-target animals (diving
birds, marine mammals)
According to UN, 70% of world’s edible
ocean fish, crustaceans, & mollusks
are declining & in urgent need of
managed conservation.
Aquaculture- controlled fish farming- is
becoming more popular
Agriculture: Soils, Green
Revolution, Gene Revolution,
Sustainable Agriculture
Importance of Soil
Important resource for growing crops!
 An ecosystem (See Ch. 12 page 219-222)
 More in the next Unit of Geology

What nutrients are important in
soil? Ask me about extra credit!
1. Nitrogen- (N)
– Need for making chlorophyll for leaves
– Rapid plant growth and healthy leaves.
– Important for leafy veggies- spinach, lettuce,
cabbage, soybeans, corn
– Deficiency results in yellow or reddish leaves.
What nutrients are important in
soil?
2. Phosphorus- (P)
– Needed for root development & growth.
– Helps produce flowers & fruit
– Deficiency results in darkening of leaves then
reddish tinge around edges.
– Important for beets, potatoes, carrots, &
radishes.
What nutrients are important in
soil?
3. Potassium- (K)
– Also called potash
– Deficiency results in puckering & yellowbrown leaves.
– Needed for
 Rapid cell growth at root tips
 Resistance to disease
 Makes stems strong
Important for potatos, beets, carrots, radishes, bud crops
(asparagus, broccoli, cauliflower)
Why should we know about soil
pH?
pH of soil can affect how
plants absorb N, P, K
 Most plants like neutral to
slightly acidic soil (6.06.8)
 Some carnivorous plants
like more acidic (4.0-5.0)
 To adjust soil pH…

– Add lime to make more
basic
– Add alum to make more
acidic
Prefer
neutral
(6.0-6.8)
Prefer
slightly
acidic
(5.0-6.5)
Prefer
strongly
acidic
(4.0-5.0)
Grains
Holly
Sundew
Veggies
Orchids
Pitcher
plants
Evergreen
Venus fly
trap
Strawberrie Azalea
s
Potato
Rhododend
ron
Carrot
camellia
What do those numbers mean on a
bag of fertilizer?



Indicates % of N, P, K in the
fertilizer
Different plants have
different nutrient needs.
Pros of commercial fertilizer:
– Greatly increases crop yield
– Greatly increase crop quality

Cons of commercial fertilizer:
– Pollute & degrade soil
– Cause eutrophication
New Crops


We have used around 3,000
different crops as food source but
now currently use about 16
different species.
Some New Crops…
– Winged beans- completely edible,
resistant to disease, enrich soil,
like warm climate
– Tricale- cross betwn wheat & rye,
likes light, sandy infertile soil,
drought resistant, tested for
growth in salty soil (might be able
to irrigate with ocean water?)
Green Revolution #1
About 50 years ago, new
strains of high yielding
wheat & rice were
developed through cross
pollination
 If given optimum levels of
fertilizer, water,
protection from pests
these will yield lots of
product.
 Poor farmers however,
cannot afford the
fertilizers, seeds,
equipment, etc so did not
help out in LDC.

The Green Revolution

What are the
characteristics of
the Green
Revolution?
Gene Revolution (2nd Green Revolution)
Genetic engineering- altering genes by splicing
genes of desirable traits & inserting into food
crop.
 Potential for

– Engineering crops to withstand salty, waterlogged, or
low nutrient soil
– “grown-in” pesticides so no spraying
– Make food more nutritious
1/3 of all corn & soybean is transgenic; 1/5 of all
cotton
 70% of all processed food is made with
transgenic material

Thursday 2/21
1.
2.
3.
4.
Turn in your Green Revolution Packet to
me.
Sign out a laptop.
Listen for info on Pest Resistance.
Be sure to bring your textbook with you
on Friday.
Pest Resistance





Bacillus thuringiensis (Bt)-
bacterium that is lethal to
butterflies & beetles.
Bt was transgenically inserted in
potatoes, cotton, & corn. Bt gives
off poison all growing season not
just when needed.
Now scientists worried this is
creating “superbugs” or Btresistant pests.
By planting non-Bt crops with Bt
crops allows some pests to “hideout” and munch (keeping them
“wild”, while others die.) By
breeding “wild-type” and Bt
exposed, may dilute recessive
resistance gene.
Negatives- can kill “non-target”
organisms (Monarch butterflies) if
pollen moved by air to milkweed
plant
Weed Control
Making plants with
herbicide resistant genes
means you can spray
heavy doses of herbicide
and kill weeds but not
crop. “Roundup Ready”
 Pros- don’t have to till so
can leave crops to fall
over & prevent soil
erosion
 Cons- may create “superweeds”

Sustainable Agriculture
Soil Conservation important in
maintaining arable land.
1.
Land management- terracing,
strip farming, contour plowing
help prevent water & wind
erosion
2.
Using cover crops (rye, alfalfa)
after harvest prevents erosion
& returns N to soil. Also use
mulch. Crop rotation!! George
Washington Carver!
3.
Use reduced tillage system
a.
b.
c.
d.
Minimal till
Conserv-till
No- till planting- best; keeps all
cover plant in place and pushes
crop seed into soil
Cons of these systems- must
use more herbicide to keep
weeds low.
No till Agriculture
Review questions
1. What is the difference between
Malnutrition and Marasmus?
 2. How would you alleviate Kwoskiorkor?
 3. Describe the Green Revolution.
 4. What is the Blue Revolution?
