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How intensive was the farming of winter wheat in the Dust Bowl region? Census data from 1930 and 1940 can help provide a picture; a picture that can be used to examine changes over the decade of the 1930s. Open the Dust Bowl: Population & Agriculture maps and display the Census & Agriculture - 1930 layer on one and the Census & Agriculture - 1940 layer on the other along with the Area of Worst Dust Storms - 1935 layer and the same basemap for each. Turn any other open layers off. Click on any county and the pop-up will reveal the nature of the data you have about each county. Note that the available data is somewhat different for the two decades.
The 1930 layer shows the number of bushels of winter wheat harvested that year divided by, or normalized by, the number of harvested acres in each county including wheat and other crops. That is, it shows the amount of wheat harvested per acre of agricultural land. The data is colored light green to dark green from least to most harvested.
• Select the 1930s layer Change Style option and click on the Options button.
• You can click on the Symbols button to change the shading pattern.
• Note that the sliders are set at 0 and 8.0 bushels per acres.
Go to the other map and change the symbols on the 1940 layer to show the same variable using the same color classification and slider settings.
Notice that at the bottom of the pop-up for each county there is a column graph showing the percentage of acres of winter wheat harvested compared to all harvested acres in the county including wheat and other crops. The graph has also been normalized - again so you can see the rate at which the harvested land is used for wheat.
Show Table for the 1930s and 1940s layers and click on the Bushels of Winter Wheat column to sort the data in either ascending or descending order. Notice that if you click on data in any row the corresponding county is highlighted in the map. You now have side-by-side maps that will allow you to compare the intensity of winter wheat farming in the Dust Bowl counties across the decade of the 1930s.