Read an Academic Passage

[1]In the early twentieth century, farmers moved onto the southern Great Plains of the United States in large numbers. High wheat prices and new tractors encouraged them to plow millions of acres of grassland. The deep-rooted native grasses they removed had held the region's dry, light soil in place for thousands of years.

[2]When a severe drought began in 1931, crops failed and the bare fields had nothing to protect them. Strong winds lifted the topsoil into enormous dust storms. In May 1934, a single storm carried dust from the plains as far east as Washington, D.C., and the Atlantic coast. Thousands of farm families, unable to grow anything, abandoned their land and moved west in search of work.

[3]The disaster led to a new approach to farming. In 1935 the federal government created the Soil Conservation Service, which paid farmers to adopt methods that kept soil in place. Farmers learned to plow along the natural curves of the land, to plant rows of trees that slowed the wind, and to leave some fields covered with grass. These practices are still widely used on the plains today.