Premium
Effects of season and management on the vane shear strength of a clay topsoil
Author(s) -
DOUGLAS J. T.
Publication year - 1986
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1986.tb00395.x
Subject(s) - topsoil , bulk density , soil water , geology , shear strength (soil) , soil science , geotechnical engineering , environmental science
SUMMARY Vane shear strength, water status and bulk density were measured at various times in a growing season at two depths in a swelling clay topsoil. The site comprised experimental plots that had been ploughed annually, or direct‐drilled for 10 years; short‐term fallow areas, created on adjacent long‐term grassland, were compared with the arable plots. In the middle of the topsoil layer (nominally 120 mm depth) of all three treatments shear strength was linearly related to water content, and similarly to bulk density in the direct‐drilled and ploughed soils. Closer to the soil surface (nominally 40 mm), relationships between strength and wetness or density were less distinct, particularly in the spring, when drying was not accompanied by an increase in strength; possible reasons for this anomaly are considered. The shear strength of the untilled soils was greater, at both depths, than that of the ploughed soil. Other factors including density, water potential, soil structure and organic constituents, differed with time or between treatments, and their contribution to variations in shear strength are discussed.