Evaluation of Combined Landscape Restoration Practices on Soil Organic Carbon Stocks in Semiarid Regions of Burkina Faso

Abstract

Forest and landscape restoration (FLR) practices have been reported to improve soil organic carbon stocks (SOCs) and contributing to climate change mitigation. This study aims to evaluate the impact of combined FLR practices, mainly developed in semiarid regions, on SOCs. The SOCs, soil texture, bulk density (ρ), pH, CO 2 emissions, and herbaceous biomass were determined at a 0 -30 cm depth. The experimental design comprised degraded land without FLR practices and three sets of combined FLR practices. These practices included "zaï " + stone bunds + organic manure + assisted natural regeneration (ANR) used to convert degraded land into forest (GF) and cropland (PARL); "zaï" + stone bunds + crop rotation + crop/fallow successions + ANR used to convert degraded land into cropland (OARL) and "zaï " + stone bunds + organic manure used to convert degraded land into cropland (KARL). SOCs were highest (20.02 t C ha −1 ) under OARL compared with the other combinations of FLR practices. SOCs increased by 99% (+0.2 t C ha −1 •yr −1 ), 58% (+0.3 t C ha −1 •yr −1 ) and 13% (+0.2 t C ha −1 •yr −1 ) under GF, OARL and KARL, respectively, and decreased by 15% (−0.1 t C ha −1 •yr −1 ) under PARL. This study provides additional information explaining SOC varia-