The conversion of forests to cropland, driven primarily by agricultural expansion, can significantly alter ecosystem services and soil multifunctionality. In this study, we examined the effects of forest-to-cropland conversion in two semi-arid areas of Spain on soil chemical properties, microbial activity, and community structure. Sampling sites included perennial crops in soil A and annual crops in soil B, compared to Aleppo pine (Pinus halepensis) forests in both locations (PS and PC). Forest-to-cropland conversion and land use type influenced soil properties, microbial activity, and carbon and nitrogen cycles. We also observed significant differences (P < 0.05) in nutrient content for the two agricultural systems compared to the PS and PC forest soils. The annual crop showed a 61% decrease in total organic carbon, which reduced enzymatic activity compared to the forest soil (PS), where the implementation of perennial crops resulted in up to four times higher levels of nutrients such as phosphorus (P). The multifunctionality of the forest (PS) in soil B showed higher values than those of the cultivated lands, while in soil A, the forest (PS) only showed greater microbial activity. According to our study, the conversion of forests to perennial crops can promote soil management in semi-arid regions. These findings highlight the importance of implementing appropriate soil management strategies after the conversion of forest lands to agricultural use, prioritizing systems that maximize overall ecosystem functioning.