Sedimentation dynamics of soil particles in sylvopastoral half-moons on restored plateaus in the Ouallam department (Niger)

The present study was conducted on the Tondibiya and Satara plateaus, in the Ouallam department (western Niger). The objective is to study the sedimentation dynamics of soil particles deposited in sylvopastoral half-moons of different years (2014, 2016 and 2018). The assessment of sedimentation was done in selected half-moons following a survey on transects. It involved the determination of the thickness of the sedimented horizon, the measurement of the permeability by the single ring infiltrometer and the granulometric analysis in the laboratory. The results obtained showed that the thickness of the sedimented horizon varies according to age and is 14.15, 17.33 and 19.37 cm in the 3, 5 and 7 year old half-moons respectively. Water infiltration was optimised by sedimentation. It was recorded 70 minutes to be constant in the 7-year half-moon and 40 minutes in the 3-year half-moon. The granulometric analysis of the sedimented particles shows their dominance by sands (77.73%). These different results show that the sylvopastoral half-moon is effective in improving the physical parameters of the soil on degraded ferruginous plateaus.