The technological trajectory of industrial fertilizers (1900–1980): the convergence between the oil industry and agriculture in the United States

Fertilizers are a significant source of greenhouse gas emissions and despite their agronomic benefits, their use is increasing due to population growth. This paper investigates the convergence of the oil industry and agriculture between 1900 and 1980, making fertilizers a focal point for scientific, technological, commercial, and industrial development. This paper uses path dependency and industry convergence literature to examine the reasons for the continued dependence on synthetic nitrogen-based fertilizers. Analyzing patents from the United States, our empirical evidence establishes four key periods of technological and industrial convergence following the Haber-Bosch process (1908-1913): i) First, a period characterized by innovations in the mechanization of agriculture (1920s–40s). ii) Major corporations, especially in the oil, petrochemical, and chemical industries, diversified and expanded after World War II. They shared knowledge across sectors, including chemistry and mechanical engineering. iii) Oil and petrochemical firms expanded by acquiring chemical producers in the 1960s. iv) Breakthroughs in new technologies emerged in biotechnologies and food chemistry after the 1970s. We argue that this trajectory is essential in gaining a precise understanding of the nitrogen fertilizer lock-in, a significant obstacle to the energy transition.