Wetland raised-field agriculture and its contribution to sustainability: Ethnoecology of a present-day African system and questions about pre-Columbian systems in the American tropics

Abstract

One adaptation for farming wetlands is constructing raised fields (RF), i.e., elevated earth structures. Studies of RF agriculture have focused mostly on the vestiges of RF that were cultivated by pre-Columbian populations in the Americas. Ironically, whereas RF agriculture is still practiced nowadays in many parts of the world, including the Congo Basin, these actively farmed RF have received scant attention. Yet, studying how RF function today can shed new light on ongoing debates about pre-Columbian RF agriculture. Also, in a context of climate change and widespread degradation of wetlands, the study of RF agriculture can help us evaluate its potential as part of an environmentally sustainable use of wetlands. We carried out an ethnoecological study of RF agriculture combining qualitative and quantitative methods over a total of eight months' fieldwork in the Congo Basin. We found that RF show great diversity in size and shape and perform several functions. Incorporation of grasses such as green manure, allows RF to produce high yields, and RF agriculture decreases flooding risk. However, it is labor-intensive and is likely always only one component of a multi-activity subsistence system, in which fishing plays a great role, that is both resilient and sustainable.