Publications des agents du Cirad


Sustainable soil management: Agro-ecology in Laos and Madagascar

Séguy L., Loyer D., Richard J.F., Millet E.. 2008. In : Ed. T. Goddard, M. Zoebisch, Y. Gan, W. Ellis, A. Watson, S. Sombatpanit. No-till farming systems. Bangkok : WASWC, p. 207-222. (World Association of Soil and Water Conservation Special Publication, 3).

The International Agricultural Research Center for Development (Centre de Coopération Internationale en Recherche Agronomique pour le Développement - CIRAD) has, for the last 15 years, initiated no-till systems in several tropical and subtropical countries, often with the support of the French Cooperation Agency (Agence Française de Développement - AFD). In particular, these systems have shown to be of interest in poor countries confronted with soil degradation problems. This paper presents the cases of Madagascar and Laos, where Direct Mulch based Cropping systems have been developed in poor and non-mechanized agriculture, and show a triple benefit (environmental, social and economical). In Madagascar, though the time for the technical development (experiment, research) of the cropping systems is now over in many parts of the Great Island, it is still questionable whether it will be possible to reach a wide-scale implementation. The 'engine' of the extension of this innovation can be: i) the awareness and support by the political Malagasy decision-makers; ii) the peasant farmer demand for these simpler, cheaper, but hazardous cropping systems; and iii) the will of the Malagasy authorities to maintain a comparative advantage of the national rice production compared to imports, providing farmers a positive incentive to adopt the innovation. In Laos, agriculture is generally not very intensive (because of scarce labor and the relative abundance of arable land) except in the areas close to Thailand where mechanization appears since inputs are more readily available. Nevertheless, the agricultural development causes a slow degradation of the natural resources, which is emphasized in areas with a higher population density. Since early 2003, a National Agro-Ecology Program (PRONAE) has promoted agro-ecological techniques on a limited number of areas where their development is particularly promising: southern Sayabury Province and Xieng Khoung Province. They provide a coherent alternate solution to slash-and-bum agriculture in the uplands, allowing for diversification and, as manpower is scarce, providing labor saving solutions. In more agricultural intensive areas, agro-ecology reduces the cropping costs and allows a faster éstablishment of crops resulting in higher yields. These two examples show that agro-ecology or "direct seeding on mulch based cropping system" presents radical changes for both the mindset as well as for the traditional ways of doing things. It is not only a system of soil conservation techniques, but also another system of production in harmony with nature. but still needing social change and widespread acceptance. (Résumé d'auteur)

Mots-clés : agroécologie; conservation des sols; mulch; brachiaria; oryza sativa; non-travail du sol; couverture végétale; semis direct; pratique culturale; république démocratique populaire lao; madagascar

Thématique : Façons culturales; Systèmes et modes de culture

Chapitre d'ouvrage