"The greatest victory which the chemist has won in the fight (...) against Nature": Nitrogenous fertilizers in Great Britain and the British Empire, 1910s-1950s.

This paper analyses the rise of synthetic nitrogen in Great Britain and its empire, from the First World War to the aftermath of the Second World War. Rather than focus solely on technological innovations and consumption statistics, it seeks to explain how nitrogen was a central element in the expansion of a form of agricultural governance, which needed simplified, stable, and seemingly universal input/output formulae. In the first half of the twentieth century, nitrogen was thus gradually constructed as a global indicator of development, as it was particularly adapted to scientific and political regimes increasingly relying upon abstraction and quantification. Yet, the history of nitrogenous fertilizers in the interwar years also shows that this cannot be reduced to a simple story of triumphant modernity, as their development and globalization was imperfect, unstable, accompanied by resistance and the resilience or emergence of other models. Rather than assuming an all-powerful "state" project, the paper thus seeks to recover the multiplicity of actors, and attempts to account for the rise of nitrogenous fertilizers; not just as the progressive application of a technological breakthrough, but as a difficult process embedded in technological, financial, and military constraints, corporate strategies, political imperatives, and the changing institutional framework of agricultural research. [ABSTRACT FROM AUTHOR]