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Susceptibility to Compression of a Clay Loam Haplaquoll
Author(s) -
Culley J. L. B.,
Larson W. E.
Publication year - 1987
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/sssaj1987.03615995005100030002x
Subject(s) - loam , tillage , compression (physics) , plough , moisture , compressibility , water content , soil science , clay soil , mineralogy , materials science , geology , geotechnical engineering , soil water , mathematics , chemistry , composite material , agronomy , biology , physics , thermodynamics
The objective of this study was to determine the compressibility of a poorly drained clay loam soil cropped to corn ( Zea mays L.) with moldboard plowing as primary tillage (CN) or with no tillage (NT). Undisturbed cylindrical cores (100 cm 3 )obtained from planter‐tracked (WT) and untracked (NWT) interrows just prior to harvest, were subjected to uniaxial compression after being equilibrated at soil moisture potentials (ψ) of −5, −10, −20, and −40 kPa. The precompression (over‐consolidated) and virgin compression regions were isolated by plotting bulk weight volume ( v ) against the logarithm of applied pressure. The breakpoint or precompression pressures (σ p ), which separated the over‐ and virgin compression regions, were determined using a statistical procedure. There was no apparent σ p for cores from CN‐NWT interrows with ψ at or above −10 kPa. Tracking of tilled interrows resulted in the presence of over‐consolidated regions at all moisture potentials. Virgin compression indices (slopes) decreased in the order CN‐NWT > CN‐WT > NT‐NWT > NT‐WT. A highly significant correlation ( p < 0.01) was obtained between σ p and the undrained strength as measured by the fall‐cone device.