Contour plowing follows the contours of hills and slopes, rather than orienting crop rows up and down a slope. It is a technique that was popularized during the New Deal and afterwards in response to soil erosion. Contour plowing furrows run crosswise to the slope, slowing runoff and allowing the soil to absorb rainfall rather than wash away. Contour plowing is usually employed along with strip cropping, that is, alternating different crops in narrow strips. Dense-rooted crops planted between row crops further helped to make full use of rainfall.
Aerial view of Burt DeWald farm, Lycoming County, about 1950
This photo illustrates contour plowing, strip cropping, windbreaks, ornamental trees, and woodlots.
Lycoming County Agricultural Extension Archives
Contour strips, Potter County, age unknown. (Site 105-WB-001)