[Campbell Biology P.856] According to the "Soil Conservation and Sustainable Agriculture" se... | Practice Question

According to the "Soil Conservation and Sustainable Agriculture" section, a major contributing factor to the American Dust Bowl in the 1930s was:

  • A: Excessive use of chemical fertilizers leading to soil toxicity.
  • B: The widespread conversion of hardy grass-covered plains into cultivated land for wheat and cattle, combined with prolonged drought.
  • C: A sudden increase in global temperatures leading to rapid desertification.
  • D: Overpopulation in the Great Plains leading to unsustainable resource consumption.

Explanation

The text explicitly states: 'Before farmers arrived, the Great Plains had been covered by hardy grasses that held the soil in place in spite of recurring droughts and torrential rains. But in the late 1800s and early 1900s, many settlers planted wheat and raised cattle. These land uses left the soil exposed to erosion by winds. A few years of drought made the problem worse. During the 1930s, huge quantities of fertile soil were blown away in 'black blizzards'.' This clearly indicates that the conversion of grasslands to cultivated land combined with prolonged drought was the major contributing factor.