Most of Crews' research focuses on understanding rates of nutrient inputs from biological N fixation, soil weathering and atmospheric deposition into managed and native ecosystems. He is involved in the development of agricultural systems that rely substantially on endogenous resources partly by increasing the synchrony between rates of resource inputs and crop uptake.Crews has developed Prescott Colleges Agroecology Program since 1995. The program is designed to provide students with in-depth theoretical and practical knowledge on topics ranging from global issues of energy availability and climate change to local issues of soil erosion, water-efficient cropping systems and nitrogen fixing rotations. As a central feature of the Agroecology program Crews oversees Prescott College's experimental farm and gardens located in Skull Valley and on the Prescott College campus. He teaches courses in Agroecology, Southwest Natural Systems Agriculture, Introduction to Soil Science, Field Methods in Agroecology, Agroecosystems of the Arid Southwest, Issues of Global Food Production and Land Stewards. B.A. 1985, Environmental Studies/Agroecology, University of California at Santa Cruz. Ph.D. 1993, Cornell University, Ecology and Evolutionary Biology Post-doc, Stanford University