Open-Source / Free Software for Applying Digital Soil Mapping Techniques in Soil Survey.

To date, digital soil mapping activities within the United States National Cooperative Soil Survey have predominantly relied upon commercial and custom software applications. As an alternative we propose a combination of two open-source and one free software package, due to their functionality, flexibility, compatibility, and availability. Our selection of software includes Pedon PC Plus, SAGA, and R. Pedon PC Plus is a custom Microsoft access database developed by the USDA-NRCS, designed to store and manipulate soil profile data. SAGA is a geographic information system developed by the SAGA Development Team with modules ranging from geomorphometry, image processing, geostatistics, and various other raster and vector operations. R is an environment for statistical computing and graphics, currently developed by the R Core Development Team. Used in combination these applications offer soil scientists access to a wide range of digital soil mapping techniques. In this poster we demonstrate the integration of these applications using data from an ongoing soil survey in the Mojave Desert of California. We show that using the aforementioned software it is possible to semi-automate the digital soil mapping process to a large degree, therefore making it more accessible to soil scientists. Our generic approach uses geo-referenced soil data queried from Pedon PC Plus, processes ancillary spatial data within SAGA, and quantifies the relationships between the soil and ancillary data using R. Although other digital soil mapping approaches are possible using this group of software, we prefer the approach outlined because it is data driven and we can use it to test our hypotheses of soil genesis.