The NAL Agricultural Thesaurus (NALT) was originally prepared by staff of the National Agricultural Library to meet the needs of the United States Department of Agriculture (USDA), Agricultural Research Service (ARS). The first edition was published on January 1, 2002, and is only available in digital form. The thesaurus is annually updated.
The thesaurus is primarily used for indexing and for improving retrieval of agricultural information. Currently, the thesaurus is the indexing vocabulary for the National Agricultural Library's bibliographic database of citations to agricultural resources, AGRICOLA. The Food Safety Research Information Office (FSRIO) and Agricultural Network Information Center (AgNIC) also use the NALT as the indexing vocabulary for their information systems. In addition, the NALT is used as an aid for locating information at the Agricultural Research Service, Economic Research Service and AgNIC web sites and databases.
The thesaurus is organized into 17 subject categories, indicated by the "Subject Category" designation. The subject categories are used to browse the Thesaurus in a specific discipline or subject area.
The subject scope of agriculture is broadly defined in the thesaurus, and includes terminology in the supporting biological, physical and social sciences. Biological nomenclature comprises a majority of the terms in the thesaurus and is located in the “Taxonomic Classification of Organisms” Subject Category. Political geography is mainly described at the country level.
For an explanation of the relationships and notes in the thesaurus, consult the "Thesaurus Structure" page.
In January 2007, definitions of terms in the thesaurus were separately published as the Glossary of Agricultural Terms. A search interface and alphabetical browse was developed to facilitate the locating of definitions for over 2,400 terms. As with the thesaurus, files were made available for downloading from the web site.
In May 2007, The National Agricultural Library (NAL) published Spanish language versions of its NAL Agricultural Thesaurus (NALT) and Glossary of Agricultural Terms, which carry the Spanish language names "Tesauro Agrícola" and "Glosario". The NALT and Glossary in Spanish supports increased Spanish language access to agricultural information throughout the United States and the World, accommodating the complexity of the Spanish language from a Western Hemisphere perspective. Translation of the NALT into Spanish was accomplished by NAL with the American Distance Education Consortium (ADEC).
In 2007, the Inter-American Institute for Cooperation on Agriculture (IICA) and the National Agricultural Library expanded their extant collaboration to include the Spanish and English language versions of the thesaurus and glossary. IICA and NAL will cooperatively develop and maintain these terminology tools to support the advancement of agricultural information in the Americas.
In 2010, the thesaurus was made available as Linked Open Data. Linked Open Data translates information into a form both readable and understandable by computers. This translation makes it possible for different information resources, such as Web pages, datasets and research articles, to be interconnected at a level far beyond what we’re used to, creating meaningful relationships that make it easier to locate related content.