SIMPLE CORRECTION METHOD OF SOIL PENETRATION RESISTANCE FOR SOIL WATER CONTENT

Soil penetration resistance (PR) assessment is a physical assessment of soil to identify compacted soil layers. Its results are influenced by soil moisture. In this study, a method for correcting PR as a function of soil water content is proposed. The proposed method employs the same function that represents the relationship between PR and soil moisture to calculate the correction that should be applied to the data. The method was evaluated in a Quartzipmment and an Oxisol, at reference moistures of 0.05 to 0.25 kg kg(-1) and 0.10 to 0.30 kg kg(-1), respectively. In addition, the efficiency was evaluated based on mean absolute error (MAE), bias, and mean absolute percentage error (MAPE). Following correction, the PR data of both soil classes followed the reference PR values (calculated for reference moisture). The largest errors were -0.474 (bias), 0.360 (MAPE), and 0.505 (MAE) for the Oxisol, and 0.112 (bias), 0.616 (MAPE), and 0.286 (MAE) for the Quartzipmment. Furthermore, the best performance occurred at a reference moisture of 0.25 and 0.10 kg kg(-1) for Oxisol and Quartzipmment, respectively. Moreover, these moistures were close to the suction pressure of 10 kPa for both soils.