Abstract

Soil organic carbon (SOC) stabilization is fundamentally controlled by soil texture and mineralogy, which vary significantly across agroecological zones. This study examines how clay content, mineral composition, and aggregate structure influence carbon stabilization mechanisms in different agroecological environments. We analyzed soil samples from 45 sites across temperate, tropical, and semi-arid zones, measuring SOC content, mineral-associated organic matter (MAOM), particulate organic matter (POM), and aggregate stability. Results showed that clay-rich soils with high smectite content exhibited 2.3-fold higher SOC stabilization rates compared to sandy soils dominated by kaolinite minerals [1, 2]. Fe and Al oxides demonstrated strong correlation (r = 0.78) with long-term carbon storage, particularly in tropical Oxisols [3]. Aggregate-protected carbon accounted for 40-65% of total SOC in temperate zones but only 25-40% in tropical regions due to different mineralogical compositions [4, 5]. Understanding these texture-mineralogy interactions is crucial for developing zone-specific carbon management strategies and improving global carbon cycle predictions [6].