Ideal soil density for subsoil material is 1.40 grams per cubic centimeter or less. Corn and soybean roots have difficulty penetrating densities in excess of 1.65 grams per cubic centimeter. Soil fertility Soil fertility is vital to a productive soil, but a fertile soil is not necessarily a productive soil. Steep slopes, poor drainage, and other factors can limit productivity. Slope and erosion Erosion is directly affected by the steepness and length of the slope.
Greater slopes increase the runoff velocity and the movement of sediment carried in runoff.
Severe or prolonged erosion can cause changes in yield potential and soil productivity, depending on topsoil thickness and subsoil properties. Losing topsoil to erosion, therefore, contributes to a loss of nitrogen, P, and K, and a decline in potential crop yield. The addition of animal manure and fertilizers can supply needed crop nutrients and help offset losses in soil fertility caused by erosion. Summary Understanding the impact of erosion on soil productivity means knowing the characteristics of your soils and their profiles. Information about soil profile characteristics is available in each county soil survey report.