Sustainable farming systems have been solutions to off-farm environmental damage and on-farm damage to agricultural resources caused by contemporary farming methods. But sustainable systems based on crop rotation generally require a lengthy transition period during which key elements of soils (organic matter, fertility, water-holding capacity) are built up. During such transition periods, farm income may be lower under sustainable systems than conventional ones. This project investigates the economics of such transition period, focusing on crop-rotation-based systems. The researchers will use the methods of resource economics to specify models of sustainable technologies, focusing particularly on the implications of biological processes as has been done for pest control and fertility. They will then investigate such transition periods empirically, using farming systems trials data from the Rodale Institute Research Center's ongoing 12-year studies. They will compare a conventional system with crop-rotation-based systems both with and without animals. Parametric and nonparametric approaches to technology estimation will be explored.