THE DUST BOWL OF the1930s

1
THE DUST BOWL OF the1930s

• Why did it happen?

2

• HARD TIMES
• The Dirty 30s
• The Great Depression
• Economic crash

3
MITIGATING CIRCUMSTANCES

• Great Depression October 1929
• People migrate from cities to farms to grow their
  own food
• Prairies cleared
• Overfarming
• surplus crops no longer needed by post-war
  Europe
• 3 years of drought
• Wind storms

4
MIGRATION FROM GREAT PLAINS TO CA

• Tenant farmers were replaced by tractors
• Farmers defaulted on bank loans due to crop
  failure
• Migrant workers followed the ripening crops

5
DUST RISING
6
LOOK!! OVER THERE
7
DUST STORM ROLLING IN
8
MENACING DUST STORM
9
DUST STORM ENGULFING A TOWN
10
DUST CLOUD
11

• Before the storm
• reduced visibility due to dust storm
• High iron content in soil result in red dust
  storms OK

12
FAR REACHING EFFECTS

• Dust storms blew north to Canada
• Dust covered Chicago
• Black Sunday
• Dust storm reached
  Washington, D.C.
• Eventually deposited in
  Atlantic Ocean

13
YOU CAN HAVE THE TRACTOR
BUT FIRST YOU HAVE TO DIG IT OUT.
14
SOIL DRIFTS
15
SOIL PILE UP
16
SOIL MOVEMENT
17
SOIL MOVEMENT
18
After THEY came

• Swarms of grasshoppers descended on fields.
  Fields of corn or alfalfa or oats could be
  destroyed in hours.
• They ate everything.

19
FORCED TO CULL HERDS

• Government bought livestock and killed them,
  burying in large pits
• Meat went uneatened

20

• The plow that changed the land.

21

• Small farmers were displaced by the use of
  tractors.

22
POWER FARMING
23
DISCING / HARROWING

• Dirt clods are broken

24
SOIL EROSION
25
EROSION
26
SOIL CONSERVATION ACT

• Farmers paid to leave land fallow
• Crop rotation encouraged by subsidies
• Encouraged alternative farming practices

27
CONTOUR PLOWING

• Contour plowing forms ridges follow the curves of
  the land, slowing water flow and saving topsoil
  replacing vertical furrows on slopes that
  formed channels that carried away seeds and
  topsoil.

28
STRIP CROPPING / TERRACING

• In between the strips of corn, beans, or wheat
  crops, farmers sowed plants with dense roots,
  such as grass or alfalfa.
• Strip cropping on different levels (terracing)
  held water and stopped soil from washing away
  in heavy rain.

29
COVER CROPS

• Planting dense soil-holding root systems on
  steeply sloped and erodible land.

30
SHELTER BELTS

• By 1938 nearly 80 million trees had been planted
  in shelterbelts in Great Plains states. The
  government used emergency funds to pay farmers
  to plant trees as a crop and instructed farmers
  how to care for and manage the trees.
• many are now being torn out

31
SOIL PROFILE

• humus organic matter
• Loam top soil
• Subsoil
• Substratum
• bedrock