SOIL EROSION & SOLUTIONS Soil formation About 500 years for 1 inch Soil Erosion Soil erosion Recycling of Earth materials Natural rates of soil erosion depend on Soil characteristics Climate Slope Type of vegetation Erosion: the beginning Raindrops: fall at ft. per second Dislodge some soil particles Sheet erosion: runoff travels over the ground May be hard to detect. Long or steep slopes contribute Erosion Source: Ramesh Venkatakrishnan Headed for the Sea Rill erosion Runoff begins to form channels. Erosion rates increase dramatically as faster moving water removes soil. Gully erosion The result of uninterrupted rill erosion Cant be smoothed out with conventional tillage equipment Soil Soil erosion In many regions the rate of soil erosion is significantly greater than the rate of soil formation Farmers now level fields with lasers to slow loss of topsoil Terraces Crops like corn are highly erosive Agricultural best management practices (BMPs) include buffer strips between fields and bodies of water Solutions to erosion Buffer strips For each of these solutions: Why does it work? Pros and cons Contour plowing Plow perpendicular to a slope Terracing No-till farming Shelterbelts Intercropping