Earth Science Rocks!Warm up October 30 Put your homework (Report on Hurricane Sandy) on your seat number if you did not finish it yesterday. Question: What is a drought?
Hurricane Sandy 22N, 76 W
Earth Science Rocks! MYP Unit Question: How does land change? Learner Profile: Caring and Principled
Earth Science Rocks! Standard: Investigate the scientific view of how the Earth’s surface is formed. Learning Target: Today I am learning about the Dust Bowl because I can see how poor farming practices and lack of soil conservation could affect me.
Activating Strategy Dust Bowl Video
The Dust Bowl 1931-1939
What was the “Dust Bowl?” • The Dust Bowl was a period of severe dust storms causing major ecological and agricultural damage to American and Canadian prairie lands from 1930 to 1939. It was caused by severe drought coupled with decades of extensive farming without any type of soil conservation.
Timeline: 1931 • Severe drought hits the mid-western and southern plains. As crops begin to die, "black blizzards" of dust begin to sweep the land. Dust from the over-plowed and over-grazed land begins to blow.
Timeline: 1932 • The number of dust storms that sweep the land begin to increase. Fourteen are reported this year.
Timeline: 1933 • There are 38 dust storms this year.
Timeline: 1934 • Great dust storms spread out from the Dust Bowl areas. The drought that occurs during this time is the worse ever in U.S. history. It covers more than 75 percent of the country and affects 27 states.
Timeline: 1935 • April 14th: This day is known as Black Sunday. The worst "black blizzard" of the Dust Bowl sweeps across the land, causing extensive damage to everything in its path.
Timeline: 1936 • The Soil Conservation Service (SCS) publishes a soil conservation district law • Many farmers begin to migrate to California.
Timeline: 1937 • FDR's Shelterbelt Project begins this year. It calls for the large-scale planting of trees across the Great Plains, stretching in a 100-mile wide zone from Canada to northern Texas.
Timeline: 1938 • There is extensive work re-plowing the land into furrows. Conservation methods result in a 65 percent reduction in the amount of soil that is blown from the land. However, the drought still continues.
Timeline: 1939 • In the fall, the rain comes and brings an end to the drought that has engulfed the plains for so long. During the next few years, with the coming of World War II, the country is pulled out of the Depression and the plains are once again golden with wheat.
Soil Facts • Five tons of topsoil spread over an acre is only as thick as a dime. • There are more than 70,000 kinds of soil in the United States. • Between five and ten tons of animal life can live in one acre of soil. • There are more living organisms in a cubic foot of soil than there are people in the United States. • It can take 100 to 500 years to create one-inch of soil. • The average quarter acre lawn contains 50 to 250 earthworms.
Ways to prevent soil erosion • Crop rotation: plant high residue (tall and bulky) crops • Tillage practices: use plows for better tillage • Surface Roughness: make ridges to reduce erosion and trap moving soil particles • Cover crops: Plant taller crops around smaller ones for cover from wind • Amount of grazing: limit the amount and rotate areas • Timing of tillage: wait to plow under crops until closer to the next planting • Irrigation: moisten the soil so it doesn’t blow away so easily. • Page 296
RAFT ROLE—you are a child living in the midwest in 1935. AUDIENCE--yourself FORMAT—diary entry TOPIC—You and your family have experienced the “Black Blizzard”. Your family is considering moving to California. Tell about your experiences so far during the dust bowl and your thoughts about whether or not you should move.