Changes in the Physico-Chemical Properties of Degraded Soils in Response to the ReviTec Approach Applied at Gawel (Far-North Cameroon)

A heavily degraded hardé area in the community of Gawel (Extreme Nord) was rehabilitated with a ReviTec approach. To evaluate the efficiency of introduced plants for rehabilitation, the site was monitored with the BioSoilPlot experiment over two years during the dry and rainy seasons (January 2018/2019, June 2018/2019, respectively). ReviTec was applied to accelerate ecological succession and improve the establishment of vegetation on these degradation-prone sites (Gawel 1 and Gawel 2). Growth volume, height and percentage cover of the herbaceous plants and soil physical and chemical parameters were assessed. Growth volume increased in both sites between 2018 and 2019 with Pennisetum pedicellatum exhibiting the highest values (Gawel 1: 3.41 dm3/m2 and 3.50 dm3/m2; Gawel 2: 3.47 dm3/m2 and 3.62 dm3/m2). Bunds were suitable for herbaceous growth, Sesbania sesban having the highest growth height (Gawel 1: 1.91 cm and 1.95 cm; Gawel 2: 1.95 cm and 1.97 cm) and Pennisetum pedicellatum the best percentage cover (Gawel 1: 53% and 58.33%; Gawel 2: 40.67% and 56.67%). Soil changed from sandy and strongly acid to clay-loam and slightly acid at Gawel 1, and from sandy and strongly acid to clay-loam and alkaline at Gawel 2. Soil water content and soil nutrient had increased within the ReviTec site compared to the outside with the application of compost-biochar-mycorrhiza treatment as the most promising over the two years of monitoring. Such results suggest that ReviTec approach can be used in sustainable restoration of soil hardé.