ABSTRACT
An ontology is a formal representation of concepts and relationships among concepts within a particular domain. In this chapter, the domain is models of agricultural and natural resource processes. There are a vast number of concepts in this domain including abstract entities such as energy, mass, organism, and mathematical operators (addition and subtraction) and specific entities such as soil chemicals, plant components, or a particular plant disease. There are many relationships among these concepts (plantwater, pest-host). A formal representation is a data structure that describes a concept or relationship and which is based on a well-defined language. Many different languages have been developed for building ontologies including the Web Ontology Language known as OWL (OWL, 2005), a W3 standard.
