Sustainable agriculture requires cooperative and coordinated action across multiple sectors and policy domains. However, farmer-stakeholder behaviors and action remain pivotal to sustainable food system management in many rural development contexts. We assess farmer pro-environmental behavioral intention through the development and application of a novel integrated approach combining two dominant psychological theories of behavior change: the Norm Activation Model (NAM) and Theory of Planned Behavior (TPB). We apply this framework to targeted research with potato growers of Kerman Province in southeastern Iran, using survey data (sample n = 381) analyzed through structural equation modeling (SEM). The integrated NAM-TPB model provides insight into both pro-social and self-interested motivations for farmer pro-environmental behavioral intention, with the model explaining 77% of total variance. We found that three variables, Awareness of Consequence (AC), Perceived Behavioral Control (PBC), and Subjective Norms (SN) were the strongest indicators of pro-environmental behavioral intention. We recommend therefore that agricultural extension and state-led farmer education should first emphasize awareness-raising of negative environmental impacts of current farming practices within training programs, and second, improve social learning amongst farmer communities through sustained farmer community engagement, thus “stabilizing” a social norm of environmental protection amongst peer networks of agricultural workers.