Which soil profiles?

In August, we posted a new collection of more than 3,400 soil profiles that are converted/formatted for crop model applications, based on the WISE 1.1 Soil Profile Database. Utilizing this new soil profiles, as described in the post, we anticipate crop modeling studies to expand their coverage areas even to the locations where no soil measurement data was previously available. For the questions of exactly how, here is a quick example application that can help you find the one(s).

Unless there is soil information collected on site exactly for the modeling purpose, your best bet on soils would be to find the closest match from the pool of available soil profiles. Depending on the scope of study, what aspects of the soils make the best/closest match can vary.

Here we set the criteria with four variables: organic carbon content, texture, available soil water content, and soil type (but this could be easily expanded to whichever variables are significant for the specific scope of study at hand). Starting from more than 3,400 soil profiles, you can narrow the list down to the profile that comes closest to fitting the specific conditions of your study site by changing the values of these four variables. Once you've found a reasonable subset of soil profiles, you can export their list, find the particular soil profile from the database file (downloadable here) and use them in your crop model application.

This quick example implies that some information about the soil properties should be available.  We assume that the minimum information available includes soil texture, some measures of fertility, and the water availability. These are also particularly sensitive properties for crop models thus they are used as the basis of the HC27 Generic Soil Profiles.

When this minimum information is not available, global soil databases, such as the Harmonized World Soil Database, can provide rough estimates; however, some properties are highly dependent on the land use and management history so that they change over time. In addition, the more soil profiles become available to us, the better the chances are of finding the closest matches in the pool of soil profiles for particular conditions.

There is a good chance that the team behind this work (the universities of Georgia and Florida) continues their work using the latest version of WISE database (v3.1) to expand the pool to more than 10,000 soil profiles in a near future; we will keep you posted on the progress.

Citation

HarvestChoice, 2010. "Which Soil Profile(s) to Choose?." International Food Policy Research Institute, Washington, DC., and University of Minnesota, St. Paul, MN. Available online at http://harvestchoice.org/node/1440.

Sep 17, 2010