SOIL TEXTURAL CLASSIFICATION BY A PHOTOSEDIMENTATION METHOD

A photosedimentation technique is used to analyze the size composition of soil samples. The number and size of the particles are determined, respectively, by the Stokes formula and the Beer-Lambert law, measuri ng time-of-flight and laser light attenuation simultaneously and hence evaluating solution turbidity. A simple software procedure has been d eveloped to obtain fractional volume size distribution, taking into ac count the particle's optical properties depending mainly on its size a nd refractive index. Laboratory measurements on calibrated particulate s, showing their reproducibility and validation as well as a classific ation of ground samples, are presented. Size distribution data can the n be utilized to obtain a textural classification of the soil samples for agricultural applications. (C) 1998 Optical Society of America.