A simulation framework for the design of grassland-based beef-cattle farms G. Martin a, b, * , R. Martin-Clouaire b , J.-P. Rellier b , M. Duru a a INRA, UMR 1248 AGIR, F-31326 Castanet Tolosan, France b INRA, UR 875 UBIA, F-31326 Castanet Tolosan, France article info Article history: Received 21 December 2009 Received in revised form 29 September 2010 Accepted 4 October 2010 Available online xxx Keywords: Farm model Flexibility Functional diversity Grassland Management strategy abstract Grassland-based beef-cattle farms are dynamic systems that are difficult to manage, particularly because of their sensitivity to uncontrollable environmental factors such as weather. The design of farms and management strategies capable of coping with a wide range of conditions is thus a challenging issue. The SEDIVER discrete-event simulation framework presented in this article has been developed to support the construction of dynamic simulation models of grassland-based beef-cattle farms for evaluation and empirical design purposes. The originality of the models built with SEDIVER lies in the explicit repre- sentation of: (i) management strategies as the planning and coordination of activities in time and space through which the farmer controls the biophysical processes occurring within the system and (ii) the diversity in plant, animals, grassland and farmland, and the management opportunities and difficulties that this might induce. An application example illustrates the kind of simulation-based investigations enabled by SEDIVER. A grassland-based beef-cattle farm in France is examined for two contrasted management strategies: the first one corresponding to the actual practice and the second one paying increased attention to and exploiting plant and grassland diversity. The simulation results showed that the second one could roughly double fodder yields and thus ensure farm self-sufficiency for fodder. Thanks to the capacity of a SEDIVER-based model to take practical production considerations into account, it is possible to increase the realism of farm simulations and the credibility and relevance of the farming systems which can thus be designed. Ó 2010 Elsevier Ltd. All rights reserved. Software availability Software name: SEDIVER (version 3.6) Contact address: Jean-Pierre Rellier, rellier@toulouse.inra.fr Year first available: 2009 Hardware and Operating System: SEDIVER runs on Linux and Microsoft Windows platforms. The DIESE library pre- compiled for Linux or for Windows respectively must be installed on the selected platform. On Microsoft Windows platforms, the distribution free Linux-like environment Cygwin must first be installed (see http://www.cygwin. com for current availability). Software required: A Java runtime environment to inspect/develop the SEDIVER framework and generate the corresponding Cþþ source code, a standard Cþþ compiler to generate the executable simulator from the source code and the DIESE library. Programming language: The functional parts of the SEDIVER framework are written in Cþþ. The input files contain specifications written in a specific language documented in the DIESE package. Interpreters for this language are included in the DIESE library. Availability: The material can be downloaded from http://carlit. toulouse.inra.fr/diese/. It comprises the DIESE package (libraries and documentation) which can be downloaded from the ‘Télécharger’ page, and the SEDIVER framework and a set of input/output files which can be downloaded from the ‘Applications’ page. 1. Introduction In less-favourable areas, beef-cattle production involves the management of a wide diversity of semi-natural grasslands. Herbage production is highly variable in space and time (Pleasants et al., 1995) due to between-field differences in vegetation types, soil conditions and topography and also to weather variability within and between years. Similarly, beef-cattle feeding require- ments change over time and between beef-cattle classes (INRA, 2007). Farmers need to be able to take decisions for planned * Corresponding author at: INRA, UMR 1248 AGIR, F-31326 Castanet Tolosan, France. Tel.: þ33 5 61 28 54 75; fax: þ33 5 6173 55 37. E-mail address: guillaume.martin@toulouse.inra.fr (G. Martin). Contents lists available at ScienceDirect Environmental Modelling & Software journal homepage: www.elsevier.com/locate/envsoft 1364-8152/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.envsoft.2010.10.002 Environmental Modelling & Software xxx (2010) 1e15 Please cite this article in press as: Martin, G., et al., A simulation framework for the design of grassland-based beef-cattle farms, Environmental Modelling & Software (2010), doi:10.1016/j.envsoft.2010.10.002