Copyright © 2017 John Wiley & Sons, Ltd. Monitoring of soil organic carbon (SOC) content, SOC pools, and enzymes involved in SOC degradation and mineralization is needed to elucidate the impact of conversion from forest to agriculture on SOC and properties, and how and which crop system and management practices can contribute to C sequestration, thus climate change mitigation. This study compared the impact of forest conversion to maize (Zea mays L.) and cactus (Opuntia ficus-indica [L.] Mill.) fields with different farming management on SOC content and pools (recalcitrant, labile, and extractable), soil microbial biomass carbon, and enzyme activities involved in the soil C cycle. For this purpose, a site under strong land use changes in Central Mexico with high demographic density was selected. Forest conversion to maize fields decreased the original SOC and the C recalcitrance index (RI). However, land use change from forest to cactus systems maintained SOC content, C RI, and arylesterase activity near the values observed in the original forest. Cactus systems promoted higher soil extractable organic carbon content, related to increases in microbial biomass and β-glucosidase activity. Additionally, cactus cultivation can maintain SOC and a C RI at a similar level to the forest soil, which contributes to sustainability of the agroecosystem and climate change mitigation. Therefore, it could comprise a promising viable option for sustainable crop production systems under temperate subhumid conditions, in turn promoting socioeconomic development and rural growth.