This paper describes a multi-agent system (MAS) model, Desktop MAS, designed for New Zealand‟s pastoral industries. Desktop MAS models the strategic decisions and behaviours of individual farmers in response to changes in their operating environment. Farmer responses determine production, economic and environmental outcomes. Each farmer has a profit-maximising or cost-minimising objective that governs their decision-making, and a social network with whom they interact. Information transfer between farmers occurs through this social network. We consider a simple scenario analysis that investigates the impact of emissions prices on industry mix and farming intensity. We then investigate the importance of farmer behaviours and interaction. We find that farmer social networks and objectives impact particularly on farming intensity decisions within land-use industries. Land-use change between industries becomes more sensitive to farmer attitudes as the profitability differential between land-uses narrows.