SPREADSHEET MACRO TO DETERMINE USDA SOIL TEXTURAL SUBCLASSES

Abstract

Texture is an important soil characteristic that is routinely determined in many soils-related studies. Although many investigators employ spreadsheets to calculate the data needed for texture determinations, a good computer-based method to identify the complete name for the texture has not been reported. In this study, I developed a technique that integrates seamlessly with spreadsheets and determines the names of the USDA soil textural subclasses. The technique uses laboratory particle size analysis data and employs a macro to execute a quantitative key to the textural subclasses. The macro is easy to use because it is incorporated in a spreadsheet file, can be called from a textbox or user defined button, and can be edited by anyone with a basic background in macro languages. The macro was written in Excel for Windows version 4.0 macro language, but opens in more recent versions of Excel for Windows and Mac. The macro has advantages over manual methods because it is much faster and not prone to errors. Advantages over existing computer-based methods are that it returns names for textural subclasses, as opposed to textural classes, requires no installation, and has a flat learning curve.

ACKNOWLEDGMENTS

I thank Bob Greenblatt for helping me getting started on this project and Eileen Creel for manually determining texture classes. This paper benefited greatly from a review by Stephen Thorne.