Soil erosion decreases agricultural soil productivity by lowering crop yields and increasing the need for fertilizer and lime. Another 100 years of erosion at 1982 levels would lower the productivity of the Nation's crop and fiber sector by 3.6 percent. This figure is an average: many soils will be little affected, a few will lose much of their productivity. Such variation in soil productivity suggests that erosion prevention funds be targeted to those acres most vulnerable. However, such targeting should also consider the mounting costs to society from offsite pollution caused by agricultural soil erosion.