Comparative physical evaluation of Uhland and Proctor samplers on a sandy savanna soil in the state of Monagas in Venezuela

Abstract

It is common to obtain agricultural soil samples using the Uhland sampler. The critical index of soil compaction is obtained with the Proctor test. The objective of this work was to perform a physical comparison between the Uhland sampler, with free and forced fall of the hammer, and the Proctor apparatus to assess mechanical alterations of the sample. Standard and modified Proctor instruments were used, as well as the Uhland with free and forced hammer fall. A completely randomized statistical design with ten replicates and four treatments was performed along with the analysis of variance, Minimum Significant Differ­ence and polynomial regression. It was concluded that Uhland and Proctor instruments pro­duced similar results. The penetrating energy of the Uhland was higher than the compacting energy of the Proctor. Humidity in the soil had an influence of the apparent dry density. The solidity ratio of the soil and the air porosity were the parameters that best identified the compaction process for the Proctor and Uhland instruments.