Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food (review)

The core of Enriching the Earth comprises an account of the discovery of ammonia synthesis by Fritz Haber and its subsequent commercialization by Carl Bosch and his coworkers at BASF. Preceding this is a detailed consideration of the place of nitrogen in agriculture, its acquisition from traditional sources in what Vaclav Smil terms “preindustrial agricultures,” and an account of efforts during the nineteenth century to secure new sources of the nutrient—for example, guano. There follow chapters on the diffusion of ammonia synthesis and its technical development since World War I, the varieties and applications of synthetic fertilizers, the extent of dependence on nitrogenous fertilizers in different agricultural regimes, and the consequences of human interference in the nitrogen cycle. The final substantive chapter reflects on the implications for human populations of the ability to manage the nitrogen cycle, reprising the argument introduced at the outset that the transformation of world food production made possible by the industrial synthesis of ammonia deserves to be regarded as the most important technical invention of the twentieth century. A brief epilogue outlines the careers of Haber and Bosch after 1918. Although the book is presented as interdisciplinary, this is meant in the sense that it includes the perspectives of various disciplines within its covers rather than integrating these within individual sections. This ensures, as Smil readily admits, that many readers will pick and choose which sections to consult. Historians of technology will probably head first for the central chapters on the work of Haber and Bosch. These draw on existing accounts in both English and German, including two substantial recent German biographies of Haber, as well as archival material held by BASF. The approach is primarily narrative, and there is little attempt to engage with the existing literature or to present new conclusions. The enlistment of ammonia production capacity in the German war machine is covered briefly, mainly as a technical triumph. The earlier sections on securing sources of nitrogen in traditional agricultures and the nineteenth-century search for additional supplies from both natural and synthetic sources may also be of interest, since they bring together material from a disparate range of sources. Those with an interest T E C H N O L O G Y A N D C U L T U R E