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Relative Erodibility of 20 California Range and Forest Soils
Author(s) -
Trott Kenneth E.,
Singer Michael J.
Publication year - 1983
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1983.03615995004700040029x
Subject(s) - soil water , vermiculite , universal soil loss equation , soil science , clay minerals , environmental science , mineralogy , hydrology (agriculture) , geology , erosion , soil loss , geotechnical engineering , geomorphology , paleontology
Erodibility research on California upland soils has indicated that the Universal Soil Loss Equation's K nomograph may not account for all of the factors affecting erodibility of western upland soils. To further investigate this, laboratory rainfall simulation on 0.6‐ by 0.6‐m plots of sieved soil at 9% slope was used to measure relative erodibility of 20 upland soils, including two soils from terraces of the Sacramento River. The most powerful predictor in a stepwise multiple regression of erodibility, on a mass basis, was a combined smectite plus vermiculite clay mineralogy term. Also included in the four‐variable regression equation was bulk density, pyrophosphate‐extractable Fe + Al, and the standard texture term M. R 2 for the equation was 0.800. Smectite plus vermiculite, M, a clay mineralogy‐pyrophosphate Fe + Al interaction term, pH, organic matter, oxalate Fe + Al, and vermiculite were the seven significant terms in the equation predicting soil loss on a volume basis. This equation had an R 2 of 0.772. For now, the best available tool for predicting erodibilities of western upland soils appears to be the Universal Soil Loss Equation erodibility nomograph. However, results of this study show that because of the large differences in parent materials and soil‐forming conditions that distinguish midwestern from western soils, consideration of soil mineralogy in future predictive work may improve the predictive capacity of the nomograph.