Soil is constantly formed by weathering of rocks.why then are we so concerned about soil erosion
Soil erosion is the depletion of topsoil that happens due to our negligence. It happens within a few moments unlike the long process of soil formation that takes millions of years. So, if we don't prevent soil erosion, then after a few years the rate of soil erosion will be greater than the rate of soil formation. This is why soil erosion is a major concern.