TITLE:
Influence of Re-Greening on the Infiltrability of Soils in South-Central Niger
AUTHORS:
Adamou Mahaman Moustapha, Issoufou Baggnian, Nazoumou Yahaya, Toudou Adam
KEYWORDS:
Infiltrability, Specific Index of Regeneration, Importance Value Index, Superficial Zones
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.19,
December
30,
2014
ABSTRACT: In the
Sahel, the climate and the agricultural practices are the main factors used to
observe regreening process. But the extension of the latter not being uniform
in the farming fields, we can suppose that there are other factors that
contribute to the re-greening of certain zones and not others. The
infiltrability of soils is considered as an important factor for these changes
in the last decades. The influence of re-greening on the infiltrability of
soils in the southern strip of Niger was studied through a comparison of zones
according to the type of sandy soils (Jigawa/Rerey),
siltyclay (Guiéza), silty-sandy (Hako) and clay-silty-sandy (Laka). The evaluated parameters are the
texture, the infiltrability and the ecological characteristics (specific index of
regeneration “SIR” and the Importance Value Index “IVI”). The main conclusions
were: the soils of Niger South-Central are characterized by a sandy texture for
more than 80%. The soils which are very sandy (“Jigawa”, “Rerey” and “Guieza”) are more permeable and have
more trees contrary to the soil Hako and Laka. Their encrusting has the
tendency to reduce the vegetation cover on the soil. The infiltration
measurements indicated that the rate of initial and stationary infiltration
diminishes while going down towards the South. In fact, it has been recorded a
rate of 123 mm/min of initial infiltration and 87 mm/min stationary in Dan Saga
on the sandy soils against 76 mm/min and 65 mm/min in Daré respectively for the initial and stationary rate. Therefore,
the infiltration seems to influence the density, the SIR and the IVI of the
trees from the North towards the South. Some additional work is necessary in
order to determine the contribution of Farmer Managed Natural Regeneration
(FMNR) in the improvement of the quality of soils and the movement of water in
the superficial zones of the soil.