Soil organic matter and enzyme activity in tropical sandy soils under integrated and conventional land uses

The preservation of soil fertility is essential for ecosystem sustainability, particularly in tropical regions where agricultural intensification often leads to rapid degradation. This study evaluated the impact of different land‐use systems on soil organic matter (SOM), enzymatic activities, and soybean productivity in tropical sandy soils. Five land‐use systems were analyzed: integrated crop–livestock–forest (ICLF), no‐tillage (NT), conventional tillage (CT), degraded pasture (PA), and native vegetation (NV). Soil samples were collected at multiple depths (0–40 cm), and chemical, biological, and physiological parameters (gas exchange and yield) were assessed. The ICLF, NT, and NV systems exhibited significantly higher soil organic carbon (SOC), total nitrogen, SOM concentrations, and enzymatic activities compared to CT and PA, with improvements largely confined to the surface layer (0–10 cm). In the 0–5 cm layer, ICLF increased SOC by 35% and SOM by 32% compared to CT, whereas NT increased SOC and SOM by 28% and 26%, respectively. β‐Glucosidase activity was 62% higher in ICLF and 55% higher in NT relative to CT. Soybean yield was 3.8‐fold higher under ICLF (3900 kg ha −1 ) and 3.5‐fold higher under NT (3600 kg ha −1 ) compared to CT (1000 kg ha −1 ). Moreover, both yield and physiological performance were consistently enhanced in ICLF and NT. These findings demonstrate that conservation‐based systems can rapidly improve soil health indicators even in sandy tropical soils, supporting sustainable agricultural intensification and aligning with global efforts to promote soil conservation and food security. Remarkably, such improvements were observed within only 2 years of experimentation.