In a letter he wrote in 1813, he described how he had subsequently adopted this style of planting, known as contour farming. “We now plough horizontally following the curvatures of the hills and hollows, on the dead level, however crooked the lines may be,” he wrote. “Every furrow thus acts as a reservoir to receive and retain the waters, all of which go to the benefit of the growing plant, instead of running off into streams.”
As this anecdote suggests, contour plowing is an old idea that makes all kinds of modern-day sense. The National Resources Conservation Service (NRCS) defines the practice as planting horizontal rows along slopes, forming hundreds of small dams. These obstacles slow water flow and increase infiltration, reducing soil erosion by as much as 50 percent compared to up- and downhill farming. This technique can also minimize fertilizer loss, reduce wear on equipment, and increase crop yields. And by reducing sediment and runoff, contour farming not only captures at least twice the rainwater, it improves water quality in and around the farm.
During the past two centuries, the nation and much of the rest of the planet largely drifted away from this technique in the interest of planting the most of a single crop with the least effort. But now contour farming is getting a fresh look, especially in parts of the world prone to more-extreme weather due to climate change.
More drops in the bucket
As a method for maximizing water resources, contour farming will be an increasingly important tool for growers to use while contending with a changing planet, scientists say. According to a study published in the journal Earth’s Future in April 2022, water will become scarce in 80 percent of the world’s agricultural fields by 2050 as a result of climate change.