Topsoil Facts: Topsoil Erosion
As an absolutely vital component of plant life on earth, topsoil is necessary to feed and foster plant growth. Without it, plants would not be able to sustain an existence. Topsoil contains 13 essential nutrients that, when dissolved in water, are absorbed by the roots of plants, fueling their growth. When the plants die, they decay and return both nutrients and organic matter back to the topsoil, completing the cycle.
Topsoil erosion occurs when topsoil is blown or washed away by wind or water. Each year approximately 25 billion tons of topsoil is lost to erosion. Erosion is worsened by the destruction of forests, over-farming and flooding. Considering that is takes about 100 years in order for one inch of topsoil to be deposited on the surface of the earth, and that only happens given the right conditions, the drastic loss of topsoil is alarming.
Topsoil erosion can be reduced by letting forests stand and by reducing aggressive and destructive agricultural practices. Natural disasters such as floods will always wash away a certain amount of topsoil, and unfortunately, flood plains contain some of the richest arable land.
One method of building rich topsoil that reproduces itself is known as the terra preta system. By combining a mixture of bone fragments, manure and charcoal with dry, barren dirt, a rich layer of topsoil can be made. Despite attempts to mitigate the loss, soil erosion is an ongoing concern.