Factors Continued...Soil Cover
Bare soil is exposed to the full erosive power of raindrops and runoff water. Vegetative canopy helps stabilize soil and controls runoff. The vegetative canopy intercepts raindrops and reduces the erosive energy of the raindrops. Dense canopies that cover much of the soil surface intercept a large proportion of the rainfall. The roots of vegetation, such as grass, bind soil particles together to resist erosion. Vegetation can also help lessen or deflect wind, intercept wind-borne sediment, and keep soils moist, making them less susceptible to wind-related erosion.
Crop or plant residue dissipates the energy available to cause erosion. A mulch or crop residue absorbs the energy of falling raindrop, lessens detachment, reduces sealing of pores in the soil surface, and promotes good water infiltration. The chart below shows residue cover effects from 0 to 100% on soil erosion reduction. For example, a residue cover of 20% will reduce erosion by 50% compared to field with no residue cover.
Using the graph above, describe the relationship of % residue cover and soil loss? Would this relationship be expected for all residue types? Why or Why not?