* Replacing the soil nutrients carried out to sea by our rivers
each year, with fertilizer, would cost R1000 million. * For
every tonne of maize, wheat, sugar or other agricultural crop
produced, South Africa loses an average of 20 tonnes of soil. *
The FAO (Food and Agriculture Organisation, a branch of United
Nations) estimates that the global loss of productive land
through erosion is 5-7 million ha/year. * speed - the faster
either moves, the more soil it can erode; * plant cover - plants
protect the soil and in their absence wind and water can do much
more damage. * plants slow down water as it flows over the land
(runoff) and this allows much of the rain to soak into the
ground; * plant roots hold the soil in position and prevent it
from being washed away; * plants break the impact of a raindrop
before it hits the soil, thus reducing its ability to erode; *
plants in wetlands and on the banks of rivers are of particular
importance as they slow down the flow of the water and their
roots bind the soil, th