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abstract 558

THE SUDONO-SAHELIAN BOCAGE:

Author(s): A multi-scale ecological alternative to climatic change.
Author(s): S. Valet (1), Ph. Le Coustumer(3), M. Motelica-Heino(2), P.S. Sarr(4)
(1)Consultant. PASSERELLES, 9, rue du Bât d’ Argent, 69001, Lyon France ; valet.serge2@wanadoo.fr ; (2) Université de BordeauxI, av. France.; (3) Unité : UMR6113 Institut des Sciences de la Terre d'Orléans (ISTO), France ; stefan.motelica-heino@univ-orleans.fr.;

Keyword(s): Run-on, run-off, AET, nutriment sequestration, traditional biophysical and innovative techniques.

Article:

Poster:

Session: Poster session 3

AbstractThe problems of the 21st century in the sudano-sahelian zone, besides the food self-sufficiency constantly

postponed to the next decade, are ecological and greatly magnified by the climatic change. Because of the double

failure of the struggle against the degradation of ecosystems and of the green revolution, promoted by agronomists,

new modes of patrimonial management of the environment are required. Though several studies have shown the

fundamental role on the agricultural zones on the hydrological balance (run off, water reserves) and on the carbon

stocks of the soil, cultivated area are poorly represented in global models. The “sustainability” of the interactions

between the production and the environment assumes the integration of the variability of the specific productivity of

media and of the spatial distribution of resources to adapt to environmental fluctuations. To reduce the dependence

of traditional food crops on environmental constrains, the management of media must rely on a large scale of

innovative and traditional biophysical techniques. These techniques are based on the run-off control and the run-on

agroforested management. The run-on is a part of the run-off and is defined as “a natural, complementary and

simultaneous irrigation to the rainfall that has generated it in according to natural (topographical, morphological,

permeability) anthropogenic (soil work) conditions”. Where the run-on infiltrates, organic carbon and nutriments that

enrich the soil deposit. Organic fertilisation practices will complete the fertilisation acquired by the soil, such as BRF,

mulching, animal feces, compost… Recommended techniques have been used separately with some result but their

joint and rational use has been poorly studied. These techniques such as quickhedges (trees and bushes), herbeous

strips, “zaï”, half-moons, earth ridges perpendicular to the slope can be implemented along the slope in combination

that will be function of the morphopedological conditions.
The results of these implementations on the

conservation of the medium and on the soil productivity, at the field and the hillslope scale, could be used to

complete and calibrate predictive models for yield (ORCHIDEE-SARRAH).

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