Résumé:
Soil organic carbon (SCO) sequestration contributes in a promising way to the mitigation of climate change by reducing greenhouse gas emissions because the soil acts as a natural carbon reservoir. The main objective of this study was to investigate the effect of arboriculture, particularly citrus and olive growing, on soil organic carbon stocks under semi-arid conditions of the agricultural workshop of Mazagran at Mostaganem. To do this, we measured the quantity of carbon using the soil of the same study area according to several soil depth levels such as: (0-15cm, 15-30cm, 30-50cm, 50-100cm). The SOCS varies significantly (p ˂ 0.05) between the different land use modes, the highest value under olive cultivation (32.63 Mg C ha-1) is recorded at the level of the stratum going from 50 to 100 cm and the highest value under citrus cultivation (24.29 Mg C ha-1) is recorded at the surface stratum ranging from 0 to 15 cm. The lowest stock is recorded at ground level under citrus cultivation in the 3rd stratum ranging from 30 to 50 cm, with 6.33 Mg C ha-1. The variation in the distribution of OC according to land use and depth could be explained on the one hand by the difference in plant inputs which differ in quantity and quality between species, and on the other hand by the difference distribution and depth of roots which control the storage and stabilisation of OC, therefore land use influences the stock of SOC at the surface and at depth.