Indigenous views of soil erosion at Fandou Béri, southwestern Niger
Introduction
An assault on the West African Sahel by drought, desiccation and degradation is said to be creating one of the most seriously degraded of environments Gritzner, 1988, Mainguet and Chemin, 1991, Warren and Khogali, 1992, Warren et al., 2001a. Land degradation is said to include nutrient mining (Breman et al., 2001) and soil erosion, in which respect the Sahel has been claimed as a global “hot spot” (Crosson, 1997).
The scientific data on soil erosion in the Sahel, good as they are in global context, are not yet sufficient to verify these claims (Warren et al., 2001a). Scientific data alone are insufficient to judge the severity of the problem, as it relates to the requirements and techniques of indigenous agriculture. Mazzucato and Niemeijer, 2000, Mazzucato and Niemeijer, 2001 are also sceptical about the evidence for soil degradation in the Sahel. They find little evidence for worsening degradation in regional crop production data, or in their detailed fieldwork in specific locations in Burkina Faso.
There are at least four ways to evaluate the role of erosion in Sahelian agriculture at the village scale. The first is to analyse erosion rates themselves and their effects on yield, using a wide range of measurement and modelling techniques (such as the EPIC model), but these have proved difficult to apply to smallholder agriculture (Michels et al., 1998). Second, resource economics, as deployed by de Graaf (1996) and Kunze (2000), assesses the monetary value of erosion to a household or individual, and/or the “willingness-to-pay” for soil conservation. This methodology, we believe, has been inconclusive because of the difficulty of reducing values to money, and making inferences from aggregate survey data in communities where there is a great variety of knowledge and practice Osbahr and Allan, 2002, Warren et al., 2001a. Third, is the finer-grained, multi-disciplinary analysis of household behaviour in relation to erosion, combining surveys with scientific measurements. We have explored this route in an earlier paper (Warren et al., 2001a), where we showed some data to support the case that it was the fields of households that had more livelihood options that suffered more erosion because these farmers relied less on fertile soils for their livelihood. A fourth approach is the ethnographic analysis of farmers' own views, assessing their technical and practical knowledge of erosion through local taxonomies and value systems. Elements of this ethnopedological approach appear frequently in this special issue of Geoderma.
The best understanding, of course, comes from cross-fertilisation between all these approaches and the adoption of multiple research techniques, particularly from comparisons of local taxonomies with appropriate science. In this respect, the francophone Sahel has proved a fertile ground. In Burkina Faso, several studies have successfully combined economic, ethnographic, and scientific data to produce a rounded picture of how erosion is perceived and combated, but also how it affects livelihood systems. These include Reenberg (1994), Reenberg et al. (1998), Batterbury (1998), Gray (1999) and Mazzucato and Niemeijer (2000). In Niger, they include Baidu-Forson and Ibro (1996), Lamers et al. (1995), Rinaudo (1996), Sterk and Haigis (1998), Bielders et al. (2001), and Hassane et al. (2000). Brouwers (1993), and Enyoung et al. (1999) have worked on these issues elsewhere in West Africa.
We are, indeed combining some of these approaches at our field site, in Fandou Béri. Our objective in this paper, accordingly, is to compare the opinions of agronomists and farmers, using a combination of survey and ethnographic research, combined with scientific measurement of erosion itself.
Section snippets
Site and methods
The research reported here focuses Fandou Béri, in southwestern Niger, which is the same village as that is described by Osbahr and Allan (2002, in this Geoderma Special Issue). Osbahr and Allan provide details of the location and most of the methods used in the research reported here. In brief, a set of nested interdisciplinary studies included studies of soil erosion Chappell, 1995, Chappell et al., 1998, Warren et al., 2001a, Warren et al., 2001b, ethnographic work on social and
Measurements
The results of the measurements of erosion are shown in Table 1. Most of the erosion is by wind, as reflected by the higher rates on sandy (tassi) soils, which underlie most of the cultivated land (the local soil terms and the distribution of soil types are explained in Osbahr and Allan, 2002, this issue). The alarming signs of water erosion in the gullies and sediment fans on the margins of the low plateaux in fact affect only small areas of cultivated land. Studies of short-term rates of wind
Discussion
The opinions among the farmers of Fandou Béri about the long-term effects of erosion on agricultural productivity are in contrast with the prevailing international discourse about the Sahel Higgins et al., 1982, Mainguet, 1998, Mainguet and Chemin, 1991, Ramaswamy and Sanders, 1992, World Bank, 1996. These opinions are derived from many sources, one of which is the literature of agronomy, although there is a plurality of view among agronomists on this issue. The concern for erosion in the
Conclusion
At Fandou Béri, as in much of the Sahel, soil erosion must be seen, as the farmers see it, in the context of much more pressing agricultural problems such as poor soils, unreliable rainfall and uncertain political and economic environments. Household strategies accommodate themselves to these circumstances by retaining great flexibility, both in terms of agricultural practice, and through resort to other sources of income. Strategies are attuned to the vastly variable circumstances of
Acknowledgments
We thank the Economic and Social Research Council (UK) who funded most of the research reported here through the Global Environmental Change programme (L320253247, L320223003), and research student grants and the Natural Environment Research Council (UK) for a research studentship to Adrian Chappell. Henny Osbahr was funded by a research grant from the ESRC (R0042973459). We also thank Joe Tabor, the editors of this special issue, the people of Fandou Béri, and our research assistants Nik
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