Answer to Question 1
It is true that erosion is always with us and that it cannot be eliminated. The goal is to not increase the rate of soil erosion by human activities. Farmers and everyone else interested in maintaining our ability to produce food should be concerned about maintaining soil fertility. Erosion decreases fertility. Our goal should be to decrease rates of erosion to background. This would result in a sustainable ecosystem that will be able to continue to provide goods and resources to the current, and future, human population.
Answer to Question 2
Urban areas face issues in the soil because so much of the soil is covered with impervious building materials like asphalt and concrete. Covering the soil leads to a loss of surface area for infiltration of rain. This leads to the problems of run-off, pollution of standing water, and a lowering of recharge for groundwater. In agricultural areas the topsoil is used constantly, depriving it of key nutrients. Depending on the farming practice used, it may result in a loss of humus and topsoil, and certainly in a loss of nutrients. This leads farmers to use fertilizers on the soil, which can lead to runoff and the pollution of standing water bodies. In addition, if the agricultural land does not receive enough annual rainfall to support the types of crops that are growing, then irrigation practices can lead to the salinization of the soil.