Challenging established narratives on soil erosion and shifting cultivation in Laos

Authors


Guillaume Lestrelin is at the Institut de Recherche pour le Développement (IRD), UMR 220 GRED, Vientiane, Lao People's Democratic Republic. E-mail: g.lestrelin@gmail.com

Olga Vigiak is at the Rutherglen Research Institute, Department of Primary Industries, Victoria, Australia. E-mail: Olga.Vigiak@dpi.vic.gov.au

Aurélie Pelletreau is at the Lao Institute for Renewable Energy, Vientiane, Lao People's Democratic Republic. E-mail: aurely_lao@yahoo.fr

Bounmy Keohavong is at Souphanouvong University, Faculty of Agriculture, Luang Prabang, Lao People's Democratic Republic. E-mail: keohavong_knu@yahoo.com

Christian Valentin is at the Institut de Recherche pour le Développement (IRD), UMR BIOEMCO, Bondy, France. E-mail: Christian.Valentin@ird.fr

Abstract

The official environmental discourse in Laos describes a “chain of degradation” stretching from upland shifting cultivation, increased runoff and soil erosion to the siltation of wetlands and reservoirs. This perspective has had wide-ranging impacts on rural development policy which, in the uplands, has long favoured forest conservation over agriculture. Integrating soil erosion and water sediment data with local perceptions of land degradation in an upland village of northern Laos, this study tests the validity of the official environmental discourse. Biophysical measurements made in a small agricultural catchment indicate a significant correlation between the spatial extent of cultivation and soil erosion rates. However, sediment yields recorded at the outlet of the catchment highlight relatively low levels of off-site sediment exportation. Furthermore, farmers' perceptions suggest that local land degradation issues and crop yield declines could be less related to soil erosion than to agricultural land shortage, increased weed competition, and fertility losses resulting from the intensification of shifting cultivation. The study concludes that a better understanding and management of land degradation issues can be achieved by developing more inclusive and scientifically-informed approaches to environmental perceptions and narratives.

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