Why did countries seek new nitrogen-fixation methods before World War I?

Before World War I, countries sought new methods of industrial nitrogen fixation primarily due to the limitations of existing natural supplies and the strategic necessity of nitrogen for military and agricultural purposes.1

By the late 19th century, the demand for nitrogen-based fertilizers to support intensive agriculture had outpaced natural sources, such as farm manure and by-products from the coal-carbonizing industry. While Chile saltpetre (sodium nitrate) served as a vital supplement, it was clear that relying on imports could not meet long-term global demands.12

Crucially, nitrogen compounds were essential for the manufacture of explosives, including gunpowder and modern munitions. Nations realized that in the event of a major war, any country cut off from Chilean supplies would be unable to produce adequate munitions. This vulnerability was a primary motivation for Germany’s development of the Haber-Bosch process, which provided an indigenous, synthetic source of ammonia and secured a critical advantage during World War I.132