There is the Glossary of Soil Science Terms, which was published by the Soil Science Society of America. They have been printing glossaries on soil terms since 1956, but the most recent copy came out in 2008 and is available on Amazon.
http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=Glossary+of+Soil+Science+Terms