Abstract

The plastic limits (lower plastic limit, PL; and liquid limit, LL) are important soil properties that can yield information on soil mechanical behaviour. The objective of this paper is to study the plastic limits of agricultural soils as functions of soil texture and organic matter (OM) content. The plastic limits were highly related to the clay content. The LL was more strongly correlated with clay than was PL, but the reasons are unclear. Interestingly, PL was virtually unaffected by clay content for soils with clay contents below similar to 35%. The OM had a strong effect on the plastic limits. This effect was clearly demonstrated when analysing soils of similar texture with a range of OM. We present equations (pedotransfer functions) for estimation of PL, LL, and plasticity index (PI) from soil texture and OM. Finally, we predict that the clay content must be >= 10% for soils without OM to be plastic; however, soils with <10% clay can be plastic if OM is present. More research is needed to investigate OM effects on soil consistency.

Keywords

Atterberg consistency limits; clay; liquid limit; pedo-transfer function; plasticity index

Published in

Soil Research
2012, Volume: 50, number: 1, pages: 7-17
Publisher: CSIRO PUBLISHING

SLU Authors

• Keller, Thomas

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    
  • Agroscope

UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1071/SR11174

Permanent link to this page (URI)

https://res.slu.se/id/publ/56401