Natural Erosion - normal geological soil movement by wind, water, ice, or gravity. Accelerated Erosion - erosion more rapid than natural erosion, primarily as a result of action by humans or other animals. Soil Loss - the removal of soil from the field of reference. Erosion has always occurred since land rose from the ocean. We are primarily concerned with accelerated erosion.
Wind erosion is hard to measure.
Sometimes use air filters, etc. Mg ha -1 assumed the maximum annual soil loss and still sustain productivity. It is estimated that more than 38 million metric tons of nitrogen, phosphorus, and potassium are lost by erosion in the U.S. each year. Experiments have shown organic matter and nitrogen in the eroded sediments to be five times as high as in the original soil. The Universal Soil Loss Equation is an equation which has been developed by USDA to uniformly evaluate soils for their potential erodibility by water.