In the United States, soil conservation first became an important political issue in the 1930s, when President Franklin D. Roosevelt led a campaign to study the loss of valuable topsoil because of erosion. It soon became clear that one source of the problem was the fact that farmers tended to plow and plant their fields according to property lines, which usually formed squares or rectangles. As a result, furrows often ran up and down the slope of a hill, forming a natural channel for the runoff of rain, and each new storm would wash away more fertile topsoil. This kind of erosion resulted not only in the loss of soil, but also in the pollution of nearby waterways.

The Soil Conservation Service was founded in 1935 as a division of the U.S. Department of Agriculture, and one of its goals was the development of farming techniques that would...