Contour farming is farming with row patterns nearly level around the hill. Each crop row serves as a small dam to hold water on a slope. In contrast, crops planted in rows up and down a hill make water run off the slope faster; this leads to soil erosion.
Compared to up and down hill farming, contour farming can cut soil losses by as much as 50 percent on long, gentle slopes. The lay of your land, or the shape and steepness of the slopes on your land determines the row pattern of your contours. Your land may be steep or irregular enough that you have more than one contour.