Estimating interrill erodibility of forest soils
Burroughs, E.R., Jr.; Luce, C.H.; Phillips, F. 1992.
Estimating interrill erodibility of forest soils.
Transactions of the ASAE, Sept.-Oct. 1992, 35(5): 1489-1495.
Keywords: sediment yield, rainfall simulation, erosion, California, interrill erosion
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Abstract:
A method to develop erodibility prediction equations was developed
and tested using published data.
Published sediment yield data for 21 California forest soils developed using
laboratory plots subjected to simulated rainfall were used to develop an
equation that explains 90% of the variation in sediment yield from the plots.
The predicted sediment yield values can be considered an index of relative
interrill erodibility because only soil type varied among the plots.
Sediment yield was a function primarily of soil texture for soils with less
than 50% Si+Cl content.
Beyong 50% Si+Cl content, the erodibilityof the soil related more to the type
of clay: kaolin or smectite.
The hypothesis proposed to explain the shape of the curve is based on
aggregate strength under rainfall.
A second hypothesis that increased silt and clay increases the degree of aggregation of the soil as a whole is rejected.
Soils with a relatively high smectite clay content had a reduced aggregate
strength and higher sediment yield when exposed to rainfall than soils with a
relatively high kaolin clay content.
The relationship of texture and clay mineral content to erodibility should be
general and applicable to other soils.
Moscow FSL publication no. 1992c
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