1_Agriculture

1_Agriculture - Land
&
Water
Use
...

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Unformatted text preview: Land
&
Water
Use
 Agriculture
 
 Feeding
a
Growing
Population
 o  As
our
population
grows
–
so
does
our
need
to
feed
 o  Human
nutritional
requirements
 o  Healthy,
balanced

diet
consists
of
proteins
(30%)
,
carbohydrates
 (60%),
and
fats
(10%)
 o  100
of
350,000
known
plant
species
are
commercially
grown
 o  90%
is
wheat
and
rice
 o  About
90%
of
grain
in
US
is
used
for
animal
feed
 o  Only
8
species
of
animal
supply
90%
of
worlds
animal
protein
 o  It
takes
16
lbs
of
grain
for
1
lb
of
meat
 o  20%
of
countries
consume
80%
of
worlds
meat
 Feeding
a
Growing
Population
 o  By
consuming
grain
directly
instead
of
consuming
the
animals
 that
feed
upon
it
 o  20‐fold
increase
in
calories
available
from
grain
 o  8‐fold
increase
in
available
protein
(meat
is
simply
more
 “concentrated”
protein
sources
than
are
plants)
 o  11
million
children
die
from
starvation
each
year
 o  850
million
considered
malnourished
 o  Results
in
stunted
growth,
weakness,
increased
disease
 susceptibility
 Green
Revolution
 o  First
green
revolution
from
1950‐1970
 o  Planting
of
monocultures,
high
use
of
inorganic
fertilizers
and
 pesticides,
widespread
artificial
irrigation
 o  While
only
25%
in
increased
farming
acreage,
there
was
a
200%
 increase
in
crop
yield
 o  Second
green
revolution
from
1970’s
to
today
 o  Genetically
engineered
crops
to
boost
yield
 Genetic
Engineering
and
Agriculture
 o  Transgenic
crops
include
pest,
drought,
mold,
and
saline
 resistance,
higher
protein
yields,
higher
vitamin
content.
 o  75%
of
all
crops
from
transgenic
crops
 o  Example
 o  Golden
rice
a
combination
of
2
daffodil
genes
and
1
bacteria
gene
 added
to
rice
to
increase
vitamin
A
content
of
rice
 Genetic
Engineering
and
Agriculture
 Pros
of
GM
Crops
 May
require
less
water
&
fertilizer
 Higher
crop
yields
 Less
spoilage
 Faster
growth
which
ay
mean
 greater
productivity,
resulting
in
 lower
operating
costs
 More
resistant
to
disease,
drought,
 frost,
and
insects
 May
be
able
to
grow
in
saltier
soils
 Cons
of
GM
Crops
 Unkown
ecological
effects
 Less
biodiversity
 May
harm
beneficial
insects
 May
pose
allergen
risks
 May
result
in
mutations
with
 unknown
consequences
 May
cause
pesticide‐resistant
 strains
 Irrigation
 o  ¾
of
all
freshwater
used
is
used
for
agriculture
 o  40%
of
crop
yields
come
from
the
16%
of
irrigated
farmland
 o  70%
of
irrigation
water
is
lost
due
to
seepage,
leakage,
and
 evaporation
and
never
reaches
the
crop
 o  1%
of
cropland
is
irrigated
with
drip
irrigation
(the
most
 efficient
irrigation)
 o  The
human
population
is
outpacing
increases
in
agriculture
 production
 Sustainable
Agriculture
 o  Three
main
goals
 o  Environmental
health
 o  Economic
profitability
 o  Social
and
economic
equity
 o  This
is
done
by
 o  o  o  o  Efficient
use
of
inputs
 Selection
of
site,
species,
and
variety
 Soil
management
 Species
diversity
 Agricultural
Pest
management
 o  Types
of
pesticides
 o  Biological

 o  Carbamates

 o  
affect
nervous
system,
potent,
water
soluble
 
 o  
bacteria,
ladybugs,
certain
wasps,
viruses…
 o  Chlorinated
hydrocarbons

 o  
synthetic
organic
compounds,
affect
nervous
system,
resistant
to
 decomposition
(example
DDT)
 Agricultural
Pest
management
 o  Types
of
pesticides
 o  Fumigants
 o  Sterilize
soil,
prevent
pests
in
stored
grain
 o  Inorganic
 o  Broad‐based
pesticides
–
arsenic,
copper,
lead,
mercury
–
highly
toxic
 and
will
accumulate
in
environment
 o  Organic
or
natural
 o  Derived
from
plants
such
as
tobacco
and
chrysanthemum
 o  Organophosphates
 o  Extremely
toxic
but
will
decompose
quickly.

Ex.
Malathion,
parathion
 Agricultural
Pest
management
 Pros
of
Pesticides
 Kill
unwanted
pests
that
carry
disease
 Increase
food
supplies
 More
food
means
food
is
less
expensive
 Cons
of
Pesticides
 Accumulate
in
food
chains
 Pests
develop
resistance
and
create
a
 pesticide
treadmill
 Estimates
range
from
$5
to
$10
in
damage
 done
to
the
environment
for
every
$1
spent
 on
pesticides;
pesticides
are
expensive
to
 purchase
and
supply
 Pesticide
runoff
and
its
effect
on
aquatic
 environments
through
biomagnification
 Inefficiency‐only
5%
of
a
pesticide
reaches
 pest
 Threatens
endangered
species
and
 pollinators;
also
affects
human
health
 Newer
pesticides
are
safer
and
more
 specific
 Reduce
labor
costs
 Agriculture
is
more
profitable
 Integrated
Pest
Management
 o  IPM
–
goal
to
control
pests
to
acceptable
levels
–
not
eradicate
 them
–
some
methods
include
 o  o  o  o  o  o  Planting
pest‐repellant
crops
 Using
mulch
to
control
weeds
 Natural
insect
predators
 Rotating
crops
often
to
disrupt
insect
cycles
 Releasing
sterilized
insects
 Developing
genetically
modified
crops
that
are
more
insect
 resistant
 Factoids
–
pesticides
and
irrigation
 o  2.5
million
tons
of
600
different
pesticides
are
used
yearly
 o  The
Environmental
Protection
Agency
has
ranked
pesticide
 residue
in
foods
as
the
third
most
serious
cancer
risk.
 o  Approximately
25
million
farm
works
are
poisoned
by
pesticides
 each
year
with
over
220,000
deaths
 o  Texas
lost
approx.
15%
of
irrigable
land
due
to
aquifer
depletion
 o  122
fish
species
in
western
US
are
endangered
or
threatened
due
 to
changes
in
water
level,
salinization,
or
silting
caused
by
 irrigation
 o  Aral
Sea
decreased
75%
and
salinity
increased
30%
due
to
 demand
for
irrigation
of
cotton
 Types
of
Agriculture
 o  o  o  o  o  o  o  o  o  o  o  o  o  o  o  Agroforestry
 Alley
cropping
 Crop
rotation
 High‐input
agriculture
 Intercropping
 Interplanting
 Low
input
 Low‐till,no‐till,
or
conservation‐till
agriculture
 Industrial
agriculture
or
corporate
farming
 Monoculture
 Plantation
 Polyculture
 Polyvarietal
cultivation
 Subsistence
 tillage
 ...
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