Title: Dust Bowl
Content:  then tripled again between 1925 and 1930. The agricultural methods favored by farmers during this period created the conditions for large-scale erosion under certain environmental conditions. The widespread conversion of the land by deep plowing and other soil preparation methods to enable agriculture eliminated the native grasses which held the soil in place and helped retain moisture during dry periods. Furthermore, cotton farmers left fields bare during winter months, when winds in the High Plains are highest, and burned the stubble as a means to control weeds prior to planting, thereby depriving the soil of organic nutrients and surface vegetation.
Title: Dust Bowl
Content:  of unusually wet weather seemingly confirmed a previously held opinion that the "formerly" semiarid area could support large-scale agriculture. At the same time, technological improvements such as mechanized plowing and mechanized harvesting made it possible to operate larger properties without increasing labor costs. The combined effects of the disruption of the Russian Revolution, which decreased the supply of wheat and other commodity crops, and World War I increased agricultural prices; this demand encouraged farmers to dramatically increase cultivation. For example, in the Llano Estacado of eastern New Mexico and northwestern Texas, the area of farmland was doubled between 1900 and 
Title: Palliser's Triangle
Content:  government completed rail and road projects, in addition to the cutting of government work budgets. During the Great Depression the Triangle, like much of the Canadian and American Prairies, was struck by the Dust Bowl in the 1930s. This was caused, in large part, by a decrease in precipitation as well as longstanding flawed farming practices that exacerbated aeolian soil erosion and dust storm activity. This includes the practice of leaving fields fallow, seen as necessary at the time to support agriculture in the given climate, as it was believed that exposed soil would better absorb and retain moisture. Measures 
Title: Dust Bowl
Content:   The Dust Bowl was a period of severe dust storms that greatly damaged the ecology and agriculture of the American and Canadian prairies during the 1930s; severe drought and a failure to apply dryland farming methods to prevent the aeolian processes (wind erosion) caused the phenomenon. The drought came in three waves: 1934, 1936, and 1939–1940, but some regions of the High Plains experienced drought conditions for as many as eight years. The Dust Bowl has been the subject of many cultural works, notably the novel The Grapes of Wrath (1939) by John Steinbeck, the folk music of Woody Guthrie, and photographs depicting the conditions of migrants by Dorothea Lange, particularly the Migrant Mother.
Title: Dust Bowl
Content:  the time. The drought dried the topsoil and over time it became friable, reduced to a powdery consistency in some places. Without the indigenous grasses in place, the high winds that occur on the plains picked up the topsoil and created the massive dust storms that marked the Dust Bowl period. The persistent dry weather caused crops to fail, leaving the plowed fields exposed to wind erosion. The fine soil of the Great Plains was easily eroded and carried east by strong continental winds. On November 11, 1933, a very strong dust storm stripped topsoil from desiccated South Dakota farmlands in one of 
Title: Dust Bowl
Content:  With insufficient understanding of the ecology of the plains, farmers had conducted extensive deep plowing of the virgin topsoil of the Great Plains during the previous decade; this had displaced the native, deep-rooted grasses that normally trapped soil and moisture even during periods of drought and high winds. The rapid mechanization of farm equipment, especially small gasoline tractors, and widespread use of the combine harvester contributed to farmers' decisions to convert arid grassland (much of which received no more than 10 inches (~250 mm) of precipitation per year) to cultivated cropland. During the drought of the 1930s, the unanchored soil turned 
Title: Droughts in the United States
Content:  The Dust Bowl or the Dirty Thirties was a period of severe dust storms causing major ecological and agricultural damage to American and Canadian prairie lands from 1930 to 1936 (in some areas until 1940). The phenomenon was caused by severe drought coupled with decades of extensive farming without crop rotation, fallow fields, cover crops or other techniques to prevent erosion. Deep plowing of the virgin topsoil of the Great Plains had displaced the natural grasses that normally kept the soil in place and trapped moisture even during periods of drought and high winds. During the drought of the 1930s, without natural anchors to keep the soil in place, it dried, turned to dust, and blew away eastward and southward in large dark 
Title: Oklahoma Panhandle
Content:  The Panhandle was severely affected by the drought of the 1930s. The drought began in 1932 and created massive dust storms. By 1935, the area was widely known as the Dust Bowl. The dust storms were largely a result of poor farming techniques and the plowing up of the native grasses that had held the fine soil in place. Despite government efforts to implement conservation measures and change the basic farming methods of the region, the Dust Bowl persisted for nearly a decade. It contributed significantly to the length of the Great Depression in the United States. Each of the three counties experienced a major loss of population during the 1930s.
Title: History of the United States (1918–1945)
Content:  to erode, and combined with the weather conditions (the 1930s was the overall warmest decade of the 20th century in North America) caused an ecological disaster. The dry soil was lifted by wind and blown into huge dust storms that blanketed entire towns, a phenomenon that continued for several years. Those who had lost their homes and livelihoods in the Dust Bowl were lured westward by advertisements for work put out by agribusiness in western states, such as California. The migrants came to be called Okies, Arkies, and other derogatory names as they flooded the labor supply of the agricultural fields, driving down wages, pitting desperate 
Title: Dust Bowl
Content:   This catastrophe intensified the economic impact of the Great Depression in the region. In 1935, many families were forced to leave their farms and travel to other areas seeking work because of the drought (which at that time had already lasted four years). The abandonment of homesteads and financial ruin resulting from catastrophic topsoil loss led to widespread hunger and poverty. Dust Bowl conditions fomented an exodus of the displaced from Texas, Oklahoma, and the surrounding Great Plains to adjacent regions. More than 500,000 Americans were left homeless. More than 350 houses had to be torn down after one storm alone. The severe drought and dust storms had left many 

Question: what were the two causes of the dust bowl?
Answer: severe drought.