Université d’Abomey-Calavi (UAC), Faculté des Sciences Humaines et Sociales (FASHS), Laboratoire de Biogéographie et d’Expertise Environnementale (LABEE), BP 677 Abomey-Calavi, Benin
The current survay aims to determine chemical parameters’ modifications of soils of Tectona grandis and Acacia auriculiformis trees of Djigbé and Ouèdo classified forests. On effect, chemical parameters (pHeau, pHKCl, organic carbon, total nitrogen, assimilable phosphorus, exchangeable cation K+) of trees soils of teck aged of 3, 7, 22 and 37 old years and Acacia auriculiformis aged of 2 and 6 old years at Ouèdo have been determined. A part from pHeau, and pHKCl, the same parameters have been determined in the litters under those trees and the linked herbal temporally abandoned soils. Statistical analyses have been performed with statistical Analysis Software system Version 9.2 and have been compared by the means of Newman Student Keuls’ test at 5 %. The litters are significantly (p < 0, 05) richer in organic carbon, total nitrogen, assimilable phosphorus and potassium in comparison with soils. The pHeau shows that the soils under trees of teck aged of 3, 7, 22 and 37 old years of Djigbé and Acacia auriculiformis aged of 2 old years are average neutral, but those under Acacia auriculiformis aged 6 old ages at Ouèdo are average acid. This research has helped to show that the soils under these trees have importante activity in mineral for the phosphorus and weak in (C, N and K+).