Effets des changements climatiques et des modes de gestion sur la fertilité des sols dans la commune de Banikoara au nord-ouest du Benin

Le present diagnostic realise dans la commune de Banikoara vise a etudier les effets des changements climatiques et des modes de gestion sur la fertilite des sols. A cet effet, les caracteristiques morphologiques et physico-chimiques de 6 unites de sols repetees 3 fois dans 3 differents arrondissements ont ete determinees et comparer a ces memes caracteristiques determinees en 1971. Les resultats d’analyses physicochimiques ont ete soumis a des analyses statistiques. Il ressort de l’etude des 2 series de caracteristiques constituees de ces resultats que les taux de matiere organique des differentes unites pedologiques de la Commune de Banikoara ont varie tres significativement entre 1971 et 2010 (p 0,05). Il en est de meme pour les taux d’azote des differentes unites pedologiques qui ont connu une variation tres significative entre la periode de 1970 et 2013 (p 0.05). It is the same for the different soil nitrogen units that have experienced a very significant variation between the period 1971 and 2010 rates (p<0.01) but did not differ significantly between one unit to another in the same series. The ANOVA results indicate that the levels of exchangeable bases (BE) and cation exchange capacity (CEC) varied significantly (p <0.01) between 1971 and 2010 and according to the soil units (p<0.01). Climate change has thus had a significant negative impact on soil fertility during the 40 years of operation, while the modes of land management did not induce a significant difference between them in terms of organic matter and nitrogen major parameters of the soil fertility. Furthermore, levels of fertility soil units went from average in 1971 to very low in 2010 out of waterlogged soils and waterlogged ferruginous soils on basic rock whose fertility levels have remained low medium and medium respectively. © 2016 International Formulae Group. All rights reserved. Keywords: Climate change, soil fertility, carbon, nitrogen, hydromorphic, ferrugenous