2Lowery B. ,Swan J. ,Schumacher T. ,Jones A. Physical proper- ties of selected soils by erosion class, Soil and Water Consl, 1995,50(3) :306 -311.
3Warkentin B. P. The changing concept of soil quality, Soil and Water Consl, 1995,50 ( 3 ) :226 - 228.
4Halvorson J.J. , Smith J. L. , Papendick R. I. Issues of scale for e- valuating soil quality,Soil and Water Consl, 1997,52( 1 ) :26- 30.
5Poesen J. W. , Torri D. , Bunte K. Effects of rock fragments on soil erosion by water at different spatial scales : a review, Cate- na,1994(23) :141 - 166.
6Bunte K. , Poesen J. W. Effects of rock fragment covers on ero- sion and transport of noncohesive sediment by shallow overland flow, Water Resources Research, 1993,29 ( 5 ) : 1415 - 1424.