What are the sources of rural unrest? Conventional wisdom suggests that when wage and employment shocks occur, workers have greater incentives to engage in contentious mobilization. Examining the case of Brazil, we show that adoption of new agricultural technology that substitutes for labor and reduces employment - specifically, mechanical tractors - contributes to rural conflict. Using counts of tractors as well as a measure of terrain ruggedness as an instrument for mechanization, we estimate the effects of agricultural mechanization on rural land invasions at the municipal level. We find that the numbers of tractors is robustly, positively correlated with conflict. We also confirm that mechanization's impact is distinct from the effects of other factors associated with rural unrest such as rainfall, landholding inequality, or nearby land reforms. Findings shed light on unanticipated political consequences of the Green Revolution and illuminate a mechanism potentially shaping rural conflict elsewhere.