The current centralized configuration of the ammonia industry is vulnerable to fossil fuel price volatility and involves complex supply chains with high transport costs. Decentralized ammonia production using small modular technologies, such as electric Haber–Bosch or electrocatalytic reduction, offers a cost-competitive alternative at the farm scale. This study evaluates the cost-competitiveness of producing low-carbon ammonia from solar agrivoltaic systems or grid electricity within a novel global fertilizer industry. Projected costs for decentralized ammonia production are compared with historical market prices from centralized production. The results show that decentralized production could achieve cost-competitiveness for up to 96% of the global ammonia demand by 2030, depending on transport costs and supply chain disruptions. These findings highlight the potential of decentralized ammonia technologies to revolutionize the fertilizer industry, particularly in regions facing food insecurity. Achieving net-zero emissions by 2050 will require transformations across industries, including the fertilizer sector. Decentralized production can mitigate issues such as high transportation costs and carbon emissions, ensuring a more resilient and equitable distribution of vital agricultural nutrients. The study provides a spatially explicit analysis of the cost-competitiveness of decentralized ammonia production, identifying regions where decentralized production can supply a significant fraction of the global demand.The current centralized configuration of the ammonia industry is vulnerable to fossil fuel price volatility and involves complex supply chains with high transport costs. Decentralized ammonia production using small modular technologies, such as electric Haber–Bosch or electrocatalytic reduction, offers a cost-competitive alternative at the farm scale. This study evaluates the cost-competitiveness of producing low-carbon ammonia from solar agrivoltaic systems or grid electricity within a novel global fertilizer industry. Projected costs for decentralized ammonia production are compared with historical market prices from centralized production. The results show that decentralized production could achieve cost-competitiveness for up to 96% of the global ammonia demand by 2030, depending on transport costs and supply chain disruptions. These findings highlight the potential of decentralized ammonia technologies to revolutionize the fertilizer industry, particularly in regions facing food insecurity. Achieving net-zero emissions by 2050 will require transformations across industries, including the fertilizer sector. Decentralized production can mitigate issues such as high transportation costs and carbon emissions, ensuring a more resilient and equitable distribution of vital agricultural nutrients. The study provides a spatially explicit analysis of the cost-competitiveness of decentralized ammonia production, identifying regions where decentralized production can supply a significant fraction of the global demand.