Intercropping—the practice of growing mixtures of crops in a single field, in contrast with the “pure stands” typical of industrial agriculture—has long been central to the discipline of agroecology. As the first generation of agroecologists saw it, research on intercropping was a recent phenomenon, dating from the 1970s and 1980s. While the evidence confirms a rapid increase in such work from the 1970s, however, what nearly all agroecologists then overlooked was the existence of two older traditions. In Europe and North America agronomists had been working on intercropping since the 1890s, while during the interwar period and into the 1950s the practice attracted considerable attention from colonial agricultural officers. Although this earlier work was in the public domain and readily accessible during the 1970s, few agroecologists took much notice.
Part of the reason for this historical amnesia may have been the common perception in the natural sciences that published work older than five or ten years is either mistaken, superseded, or irrelevant. Similarly, in arguing for alternatives to industrial agriculture from the 1970s, agroecologists may have felt it preferable to portray intercropping as a new and promising technique rather than as one which long predated “scientific agriculture.” More generally, however, it is likely that the decline and rebirth of intercropping-research is part of a more general twentieth-century phenomenon, whereby a wide variety of alternative cultivation practices were marginalized after 1945, only to re-emerge after the 1970s as the social and environmental consequences of industrial agriculture came under attack.