Programme Poster session 3
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 ; email@example.com ; (2) Université de BordeauxI, av. France.; (3) Unité :
UMR6113 Institut des Sciences de la Terre d'Orléans (ISTO), France ; firstname.lastname@example.org.;
Keyword(s): Run-on, run-off, AET, nutriment
sequestration, traditional biophysical and innovative techniques.
Session: Poster session 3
The 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).