Effect of organic carbon content on the compactibility and penetration resistance of two soils formed from loess

Abstract

Penetration resistance and bulk density were measured in the laboratory for two soils: grey-brown and brown, both formed from loess with different C org. content which had been compacted using the Proctor test. The compaction was carried out at different moisture contentofthe soils. Values of bulk density and penetration resistance of the soils increased with increased moisture content up to maximal values after which the values decreased with further increments in moisture content. Increased content of C org. caused a decrease of compactibility of the investigated soils and a decrease of their penetration resistance in dependence on their moisture content and bulk density. Maximum values of penetration resistance decreased and the corresponding moisture content increased with increasing C org. content in both soils formed from loess. C org. content in analyzed soils had a great effect on the relation between penetration resistance and soil moisture and its bulk density.