Factors contributing to the tensile strength and friability of Oxisols

IMHOFF, S.; DA SILVA, AP.; DEXTER, A.

Charlotte (NC)

Congreso; SUSTAINING EARTH AND ITS PEOPLE: TRANSLATING SCIENCE INTO PRACTICE; 2001

ASA

Tensile strength and friability are considered useful indicators of soil structural quality.This study hypothesized that there is a relationship between soil intrinsic properties and tensile strength – friability in Oxisols. This research was conducted on a sugar-cane farm and sampling sites (n=25) were located along an Oxisols catena. The transect crossed three soil types: clayey Rhodic Hapludox, loamy Typic Hapludox, and sandy Typic Hapludox. Each sample comprised thirty five aggregates collected from the top layer. Tensile strength (TS), friability (F), size particle distribution, organic matter, crystalline and poorly crystalline oxides were measured. Multiple regression analysis showed that TS was positively related (R2=0.92) with clay+silt content and organic matter, and that poorly crystalline iron oxides were the constituent of clay+silt fractions that most contributed to TS. Results also indicated that the soils were highly friable, with the crystalline iron forms being positively related with soil friability.