By Lynn Betts
Let's say you've come to the point that you're using no-till or till-plant systems with technology like autosteering that give you most of the benefits of precision farming. That's great news. If you're farming fairly level land, or sloping land with terraces or other practices that have established row patterns that fit the contour of the land, you're set.
But what if you have the opportunity to rent or buy some rolling land that's farmed up and down hill that needs to be farmed on the contour?
Contour farming, still one of the most cost-effective soil conservation practices around, brings elevation, the third coordinate of spatial relationships in real-world farming, to the forefront in row pattern consideration.
Soil loss reductions with contouring vary widely, depending on severity of storms, length and steepness of slope, amount of ground cover, and height of soil ridges formed by tillage or planting equipment. Contouring can save significant amounts of soil- -- especially when heavy residues are left on the field to encourage water infiltration and when high ridges are formed on a contour with equipment.
Contouring also guards against up and down hill farming problems of seeds or young plants being washed out of the row during heavy rains, along with the best of your topsoil. Farming around the hill also promotes infiltration of rainfall, as each contour row is a small dam that holds falling rainwater on the hillside. It's a solid practice that's been a staple of conservation on steep slopes for decades.
Contouring a lost art
Old-time conservationists called contouring an art as much as a science. It seems simple enough to follow the contour of a slope around the hill, more or less on the level. But in practice, goals of contouring also include developing a pattern that promotes long rows, eliminates as many point rows as possible, and maintains grassed waterways with row directions that neither erode soil nor dump sediment into the waterway.
As conservation technicians with contour experience have retired, contour farming has become secondary to conservation tillage, water and sediment control basins, and other practices more accommodating to farm large machinery. Today, it can be difficult to find technicians with strong skills in setting contour lines and laying out complex contour systems.
Technology available, but…
The know-how, software and hardware can be made available to lay out and drive contour lines from your own tractor cab -- if you live in the right county in the right state. The power behind contours, LiDAR elevation data, is available in some to all counties in states from the Great Plains to the East Coast.