The Development of the Legend to the Provisional Soil Map of East Africa as a Case Study in Colonial Soil Science

ABSTRACT The Provisional Soil Map of East Africa (PSMEA), published in 1936, was produced by soil scientists in what were then British East African territories. It was an innovative contribution to soil mapping, summarising available information and communicating its incomplete and patchy distribution to the user. In this paper we examine the emergence of the map legend, using proceedings from two key meetings convened for East African soil chemists in 1932 and 1934, and associated correspondence, notes and publications. We consider the international context of the map's production, focusing on attempts to coordinate the efforts of colonial soil scientists in Britain's African territories, and the emergence of an international agenda to map soils at global scale in the aftermath of the formation of the International Soil Science Society (ISSS) (now International Union of Soil Sciences). We examine evidence for the attitudes to indigenous soil knowledge among colonial scientists at the time, showing how this perspective was marginalised, even though it underpinned research in Zambia. We show how, contrary to common assumptions about colonial science, the network behind the East African map was connected to international deliberations on soil survey and made innovative contributions while critiquing proposals from key international experts. We also show the importance of exchange of ideas between the East African team and Colin G. Trapnell, in Zambia. We then outline the later influence of the East African map, and its connections to D'Hoore's Soil Map of Africa.