Grains that are able to be lifted by the air stream but which fall back to the surface after a 'short' distance are traveling in saltation . These grains are moving by creep . Grains less than 20-30 microns are small enough to respond to turbulent fluctuations in the air stream and their motion is defined by turbulent diffusion. These grains are traveling by suspension and may remain airborne until rain washes them out of the air, often being deposited many kilometers downwind. Saltating grains are potentially most damaging to crops.
Impact energy can be high particularly in high winds causing leaf and stem damage to young plants.
Additionally, impacting grains are a primary method through which PM10-sized particles are suspended into the air stream. Though only a small fraction of total transport, suspended particles impact visibility, often kilometers downwind of their entrainment point, reduces soil productivity over time and contributes to health-related imparements in animals and humans alike. Surface stability, and therefore resistance to erosion, is related to three primary factors. Although factors 1 and 3 are outside of human control, growers have learned to adapt cropping systems which are compatible with the climate regime. It is in this area that growers can alter the susceptibility of a particular soil to wind erosion processes.