Known to the layperson as "dirt," topsoil is the outermost layer of the earth's crust. Rich in nutrients and organic matter, it hosts crops and wild flora worldwide. In fact, without topsoil, humanity would have died out long ago. While that statement might strike some as extreme, the evidence for it can be found in erosion. When this vital geological tier is removed by wind or water--due to natural forces and human activity--life-giving elements are likewise evacuated, leaving barren land bereft of growth. All is not lost, however. There are ways to prevent soil erosion.
Live stakes are cut branches from hardwood trees replanted inhospitable soil. They are called live stakes because they usually have no twig or leaf extensions. With the capacity to take root and form new trees, the live stakes gradually stabilize the underlying soil and secure it against erosive forces. Planting them during the winter allows the stakes to establish themselves when the growing season arrives. Although some branch cuttings take to the host soil very well on their own, others require an application of rooting hormone for best results.
Fascines are another way in which to control erosion. By binding branches, rods, or piping together, engineers can strengthen embankments and marsh soil as they strategically insert the bundles into trenches. In short, the sticks are fashioned into logs from which plant cover will grow. Meanwhile, the fascines establish root systems--as with live stakes--that keep the topsoil in place. In addition to strengthening soil structure, this method interrupts the slope, thus slowing the velocity of movement.
Brush layers -- are composed of material from woody plants that are native to the area under scrutiny. They should ideally be freshly cut, i.e., embedded within 48 hours of extraction. Planted at an angle to a slope or incline, the cuttings are driven in the butt-end first. Often inserted at embankments, brush layers convey food and cover for fish in the adjacent water body while stifling the downhill flow of rainwater.
Native plants -- capture water, interrupt its force, and fortify the soil beneath. Like bundled cuttings and stakes, they can decrease erosion rates by as much as 50 percent. Their natural adaptation to regional soil and atmospheric conditions gives native plants their edge. This makes them more independent and less needy of management.
Grasses -- are excellent counter-measures to erosive activity because they possess coarse and muscular root systems that hold soil molecules in a place like few other floral categories. Like other plants, native grasses are optimal for the preservation of topsoil. A county extension office of the state's land-grant university is a helpful resource in determining the best grass variety.
People should neither underestimate the destructive results of erosion nor over-estimate the steps to remediate the problem. As demonstrated above, the proper placement and planting of vegetative organisms can qualitatively stanch the runoff flow.