Computer Modeling of Beef Cattle Grazing Under Changing Climate, Land Use, and Markets

Abstract. The extended drought in the Southern Great Plains and California in recent years has highlighted the need to address vulnerability of farm production systems to climate extremes. In particular, beef cattle production suffered a severe setback as a result of prolonged drought in southwestern U.S. In response to this need, a multidisciplinary and multi-institutional project funded by the United States Department of Agriculture is under way to evaluate alternative mitigation strategies that will enable beef cattle grazing systems to be more resilient under climate change, land use, and global market pressures.As part of this multifaceted effort, an integrated computer modeling and analysis framework has been developed, which will be used to evaluate alternative mitigation and adaptation strategies for beef production systems. This paper provides a synopsis of the main components of the modeling and analysis system, including a module for automatically generating representative farms, an environmental module consisting of Agricultural Policy Environmental eXtender (APEX), a field scale model, and Manure Denitrification/Decomposition (DNDC) model, and an economic module consisting of the Farm-level Economic Model (FEM). Extensive databases that have been developed as well as an interface with a comprehensive life cycle analysis program are also presented.