Physical and Chemical Properties of Soil in the Sahelian Region: Case Study in Nioro du Rip, Senegal
Landing Biaye *
Department of Geology, Faculty of Science and Technology, Cheikh Anta Diop University, Dakar, Senegal.
Fary Diome
Institute of Earth Sciences, Faculty of Science and Technology, B. P. 5396, Dakar-Fann Senegal.
Seybatou Diop
Institute of Earth Sciences, Faculty of Science and Technology, B. P. 5396, Dakar-Fann Senegal.
Modou Mbaye
Institute of Earth Sciences, Faculty of Science and Technology, B. P. 5396, Dakar-Fann Senegal and Department of Physics, Faculty of Science and Technology, Cheikh Anta Diop University, Dakar, Senegal.
Djibril Tine
Institute of Earth Sciences, Faculty of Science and Technology, B. P. 5396, Dakar-Fann Senegal.
Dome Tine
Institute of Earth Sciences, Faculty of Science and Technology, B. P. 5396, Dakar-Fann Senegal.
Ndeye Penda Dione Diene
Head of the Analysis Laboratories (GLA) group of the Mining Exploration and Promotion Directorate, Senegal.
Gayane Faye
Institute of Earth Sciences, Faculty of Science and Technology, B. P. 5396, Dakar-Fann Senegal.
*Author to whom correspondence should be addressed.
Abstract
The locality of Nioro du Rip is facing intense erosion, loss of agricultural land, soil pollution and soil degradation. Today, there is limited information about the soil physical and chemical properties in the locality. In this work, we describe the main essential factors or mechanism that control the evolution of the soil in the study area.
The physical and chemical properties of soils encountered along a NE-SW transect in are analyzed in this paper. The statistical analysis results revealed low structural stability of soils in general, due to their low organic matter content and exchangeable bases and their predominantly silty texture. A net trend towards acidification, which is more pronounced in the lower-bottom and terrace soils, provides information on the conditions that are increasingly unfavorable to agricultural development.
The multivariate principal component analysis (PCA) identified the preponderance of two factors among the four primarily involved in soil geochemical composition. These include a mineralization process (expressed through the first principal component (PC1), which causes soils to be rich in elements (Ca2+, K+,C, N, MO) controlling their structure and fertility level; The PC2 axis expresses the spatial differentiation phenomenon of the soil granulometric composition: soils forming cluster poles according to their textural affinity in the projection of the plane formed by these two components , with on one side the sandy-dominated soils of the shallows and terraces and on the other the clay-dominated soils of the plateau and the slope. A clear reversal of textural polarity in the studied topo sequence that must be blamed on the strong water erosion in this area.
Keywords: Soil, physical and chemical, erosion, principal component analysis assessment.