University of Sussex

Department Member, Anthropology

About

My research in Nicaragua (5 months), Brazil (22 months) and Liberia (9 months) has involved long-term ethnographic and quantitative fieldwork, living with subsistence farmers, combining the study of local environmental knowledge and practices with research in human geography, human ecology, social anthropology, historical ecology, agroecology and archaeology. I have been combining these fields to examine the relationship between people, agrobiodiversity and anthropogenic dark earths (ADE), initially in Brazilian Amazonia (doctoral research, awarded 2009) and now in West Africa (on-going post-doctoral research).

Current interest and research around biochar lies in the appreciation of Amazonian terra preta: the highly fertile, carbon-enriched “anthropogenic dark earths” that formed through the settlement and everyday practices of pre-Columbian populations up to 2000 years ago. Research on the farmers that cultivate ADE in the Amazon today is important because annual fields on ADE can support a wider range of crops at high yield, with shorter fallows, while agroforestry systems can likewise support a greater diversity of tree species, when compared to background soils. Study of these cropping systems can shed light on pre-Columbian agriculture, at the same time as it can point to future sustainable forms of land-use. My doctoral research overturned an existing consensus that the Amazonian staple, bitter manioc, is not suited to cultivation in ADE. I demonstrated, to the contrary, that local people have adapted bitter manioc landraces and farming systems to ADE soils. I also showed how homegardens on ADE support greater agrobiodiversity than those on background soils. A comparative study of ADE in blackwater and whitewater regions showed how divergent historical ecologies have shaped current land-use on these soils.

It is now suggested that the kind of carbon enrichment found in ADE (and perhaps able to be replicated in part through modern biochar technologies) could be transferred elsewhere - in particular to Africa. This perspective overlooks the possibility that smallholder farmers in Africa already produce and use ADE as part of their existing repertoire of “indigenous” knowledge and land use (see profile photos in my papers). My post-doctoral research in West Africa (currently being written up) will demonstrate that this is the case – even though it has, to date, gone unnoticed by soil and agricultural scientists and those researching and developing biochar systems.