Fulfilling the production objectives of a grassland-based beef system requires a robust management strategy to secure the best practicable use of forage resources with regard to the cattle demand. To address the challenging issue of designing such strategies, this article describes the application of an ontology of agricultural production systems to the generic conceptual model SEDIVER, which supports the representation and dynamic farm-scale simulation of specific grassland-based beef systems.

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... The most salient and novel aspects of SEDIVER concern the explicit modeling of (a) the diversity in plant, grassland, animal and farmland, and (b) management strategies that deal with the planning and coordination of activities whereby the farmer controls the biophysical processes. By using the SEDIVER conceptual framework, part of the subjective and context-specific knowledge used in farm management can be captured and, in this way, enable scientific investigation of management practices. herbage production is very heterogeneous and variable in time and space (Parsons, 1988) . This is partly because of the variation in vegetation types in relation to management intensity and environmental factors, mainly soil conditions and topography, and partly because of weather variability within and between years. The management challenge is thus to make efficient use of grassland production, and to secure the feeding of the herd in accordance with desired, attainable and currently usable herbage production. Of primary importance for farmers is the development of greater flexibility in farm management, enabling them to take advantage