Agriculture is offering new forms of support to society, as evidenced by rapid development of an agricultural "bio-economy," and increasing emphasis on production of ecological services in farmed landscapes. The advent of these innovations will engage agricultural professionals in critical civic debates about matters that are complex and that will often be controversial, and thus demand new sets of professional capacities that extend significantly beyond technical expertise. Specifically, agriculturalists will need a capacity to facilitating challenges to, and where appropriate, changes in prevailing worldviews--their own as well as those of others. In this article we report on pedagogy that aims to build such capacity, via a semester-length course on critical engagement in sustainable development of agricultural and other managed ecosystems. In the course we aimed to help prepare students to engage as professionals in critical discourse under circumstances where prevailing worldviews about agricultural development vary significantly among different stakeholders. We used experiential learning to encourage students to critically examine individual and collective worldviews and "mental models" relevant to sustainable development challenges. Experiential learning was particularly featured in an extended exercise in "scenario planning," a method of systemic analysis of alternative scenarios of future development in which the students began to function as a critical learning system. In reflective and evaluative essays, students indicated favorable evaluations of their learning experience and provided evidence of increased capacities highly relevant to civic professionalism within the context of the quest for sustainability as agriculture offers new forms of life support to society. (Contains 2 figures.)