Impacts des aménagements à courbes de niveaux (ACN) végétalisés ou non sur l’amélioration de la charge en eau du sol dans les Cercles de Koutiala et Yorosso, Mali.
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Catherine Dembele. (31/3/2020). Impacts des aménagements à courbes de niveaux (ACN) végétalisés ou non sur l’amélioration de la charge en eau du sol dans les Cercles de Koutiala et Yorosso, Mali.
Abstract
In the Sahelian zones, climate change results in insufficient rainfall, which is poorly distributed
in time and space, and a decline in soil fertility mainly due to erosion and over-exploitation.
This study is based on soil water conservation on plots managed with vegetated or nonvegetated
contour
bunds.
The
objective
of
this
study
is
to
measure
the
improvement
of
the
soil
water
recharge
under the management with vegetated bunds or not in the villages of
Dionkounda, Kiffosso, M'Pessoba and N'golonianasso in the District of Yorosso and Koutiala,
in southern Mali. The soil infiltration measurements were carried out from September to
December 2019 using single ring infiltrometer upstream and downstream along the bunds built
on contour lines created in August 2015 for the M'Pessoba technology park and in August 2016
for the technological park of N’golonianasso and reinforced with 4 types of vegetation; natural
herbaceous vegetation, bursts of strains of Andropogon gayanus a perennial herb and two
woody species Gliricidia sepium and Acacia colei. The infiltration rate and the saturated
hydraulic conductivity were estimated from the data collected and subjected to statistical
analyzes to determine the effects of bunds and type of vegetation on the rate of infiltration of
soil water. The results of the analysis revealed a significant difference in the rate of infiltration
between the types of vegetation established along the earth bunds constructed along the contour
lines. The highest infiltration rate was observed for bunds reinforced with woody species, G.
sepium (299.5 ± 3.6 mm / h), followed by A. colei (232.2 ± 2 mm / h), A. gayanus (189.4 ± 2.5
mm / h) and natural herbaceous vegetation (132 ± 2.3 mm / h). The rate of soil water infiltration
was higher for the downstream areas compared to upstream for the 2 woody species. These
results revealed the positive impact of woody species on improving the soil water rate
infiltration compared to A. gayanus and the natural vegetation consisting essentially of annual
herbaceous species
