Topic 3.2 — Soil erosion
Controlling factors
Erosivity (the capacity of rain and runoff to cause erosion). To reduce erosivity, vegetation cover decreases the energy of rainfall and runoff — plants and organic residues act as barriers that reduce water velocity.
Erodibility (the susceptibility of soil particles to detachment). Erodibility can be reduced by raising soil organic matter, liming, or adding amendments that increase aggregate stability or cohesion.
Slope length and angle. Steep and long slopes accelerate erosion. Contour-plowing, terracing, and barriers such as vegetation strips placed perpendicular to the slope reduce flow velocity and increase infiltration.