Management of grazing systems: from decision and biophysical models to principles for action

Changes in forage systems taking into account new environmental issues often lead to a reappraisal of the agricultural practices by farmers. These changes also raise new issues about the relevancy of traditional practices of grassland management. We therefore propose an analytical scheme to describe a production plan compatible with land resources (sown or native grasslands). To that end, we present a conceptual model that can be used to design a set of grazing management practices suited to a diversity of specifications. It involves of a combination of defoliation and fertilizer practices allowing different targets to be achieved in terms of herbage yield, composition, and grassland biodiversity. Finally, we suggest several management principles underlying these changes in forage systems. These management principles allow to take decisions on a monthly to yearly basis, to assess the conformity between farm resources and farmers’ objectives, and to coordinate different combinations of herd and land at different periods of the year.