ABSTRACT
Comparison of local and zonal variations of soil loss may then be possible. Alternatively, a tentative order-of-magnitude ranking of several terrain units may be possible in terms of annual soil loss. Strata have been defined from cover type alone or from a combination of variables commonly cited as soil loss controls: for example, slope angle, grain-size characteristics and proportion of total plot area without vegetation. In the agricultural sciences this is of lesser significance than in geomorphology, since usually the intention is to monitor the erosional effects of different plot treatments. In addition, agricultural terrain conditions are much more spatially uniform than the natural slopes investigated by geomorphologists. Clusters based on plot-scale measurements have a more homogeneous soil loss response than response derived from map-scale data. As noted earlier under soil loss prediction, plots are small relative to the slope profiles on which they occur, so that distance from divide does not emerge as an erosional control.
