Determination of Some Soil Properties on Penetration Resistance and Consistency Limits

Abstract

Atterberg limits and penetration resistance are the factors that affect the mechanical behavior of soil. In this study, it was investigated the direct and indirect effect of some soil properties such as particle size distribution, moisture and organic matter content, aggregation rate, aggregate stability, and clay activity index on penetration resistance, liquid limit, plastic limit, and plasticity index and revealing the change of all studied properties along with the soil layers. A pasture was selected as the study area and 20 sample points were determined randomly. Penetration resistance (PR) was measured with a penetrologger at these points and soil samples were taken from three different soil layers (0-25, 25-50, and 50-75 cm). The analyses were carried out to determine the soil properties in the laboratory. One-way variance analysis (ANOVA) was used to determine the variation of the soil properties along with the sample layers, and the path analysis was used to determine the direct-indirect effects of the properties affecting the penetration resistance, liquid limit, plastic limit, and plasticity index. The path analysis results showed that clay content directly affected the penetration resistance with the highest coefficient, and organic matter content affected the aggregation rate. The clay content had the highest direct effect, and the organic matter content had the highest indirect effect on the penetration resistance. The highest direct effect coefficient was obtained from organic matter in the plastic limit and liquid limit, while the aggregation rate was in the plasticity index.