Pontificia Universidad Católica de Chile Pontificia Universidad Católica de Chile
Acevedo S.E., Contreras C.P., Ávila C.J., Bonilla C.A. (2021)

Testing the integral suspension pressure method for soil particle size analysis across a range of soil organic matter contents

Revista : International Agrophysics
Volumen : 35
Páginas : 357-363
Tipo de publicación : ISI Ir a publicación


Particle-size distribution is a critical part of soil description, which is commonly measured using pipette and hydrometer methods. However, a recently developed technique, called the integral suspension pressure method, allows for the measurement of continuous particle-size distribution based on Stokes’ law. The objective of this study was to evaluate the appli- cability of the integral suspension pressure method for measuring particle-size distribution, as an alternative to the standard hydrom- eter procedure. The integral suspension pressure method was tested by using a soil dataset with a wide range of organic matter contents (0.22-12.0%). Forty-nine samples were analysed with a hydrom- eter after organic matter removal and the results were compared with those obtained using the integral suspension pressure method. Through comparing the integral suspension pressure and hydrom- eter measurements, root mean square error values of 8.9, 8.1, and 11.9% were observed for sand, silt, and clay, respectively. The clay fraction was underestimated throughout the entire range of meas- urements. Conversely, the silt content was overestimated over the whole range of measurements, especially in samples with more than 36% silt. When compared to the hydrometer method, integral suspension pressure integral suspension pressure exhibited a ten- dency to misclassify the soil texture of clay loam samples but was accurate for sandy loams.