Effects of Land Restoration Technologies on Soil Physicochemical Properties Across Five Sahelian Countries: Evidence from Multivariate Analyses

Land degradation is a major constraint on agricultural productivity and livelihoods in the Sahel, where erosion, declining soil fertility, and climate variability threaten the sustainability of production systems. This study assesses the effects of land reclamation projects on soil quality at 50 resilience sites supported by the World Food Program in Burkina Faso, Mali, Niger, Senegal, and Chad. Soil samples were collected from treated and control plots at depths of 0–20 and 20–40 cm and then analyzed for their key physicochemical properties, organic matter, and organic carbon. Forty-three sites also provided usable agronomic, agroecological, and socio-organizational data. The results show a significant improvement in soil fertility in the managed plots, with increases in organic matter from 24.2% to 77%, total nitrogen from 15.7% to 52.9%, available phosphorus from 36.5% to 176%, and exchangeable potassium from 39% to 47%. The pH generally increases by 0.40 to 0.52 units, while bulk density decreases by 2.0 to 8.4%. The magnitude of the responses varies depending on soil texture and pedoclimatic conditions. These results confirm the role of water and soil conservation/soil defense and restoration structures as a lever for restoring the quality and fertility of Sahelian soils.