This paper examines how historical rice-farming traditions shape modern innovation outcomes in China. Using county-level data and a spatial regression discontinuity design centered on the Qinling–Huaihe Line—the geographic boundary separating traditional rice and wheat farming regions—we investigate whether deep-rooted cultural legacies constrain the quality of innovation, as measured by invention patent success rates. The results show that regions with a rice-farming legacy exhibit significantly lower innovation success, despite no observable effect on the number of enterprises. This pattern suggests that collectivist cultural traits, shaped by historical agricultural systems, continue to suppress risk-taking and originality, which are essential for high-quality innovation, even within modern institutional environments. Our findings contribute to the literature on cultural economics by demonstrating that the impact of historical norms varies across types of economic activity. While modern institutions may support general entrepreneurship, they appear insufficient to overcome deeper cultural constraints on innovation effectiveness. These insights highlight the need for targeted strategies, such as incentive structures and cultural interventions, to foster breakthrough innovation in culturally risk-averse contexts.