Soil organic carbon (SOC) underpins agricultural sustainability and the terrestrial carbon cycle, yet its vertical distribution and stabilization across soil depth remain poorly constrained at large spatial scales. Here, we present a nationwide, depth‐resolved dataset of SOC and mineral‐associated organic carbon (MAOC)—the more persistent SOC fraction—from 365 dryland cropland sites across China, sampled to 2 m depth. Contrary...

Soil mineral‐associated organic carbon (MAOC) constitutes over 50% of total soil organic carbon (SOC) and serves as a key determinant of its long‐term stabilization. Although soil pH is recognized as a “master variable” in biogeochemical cycles, it remains unclear how soil pH influences MAOC and SOC at large spatial scales. To address this knowledge gap, we conducted a continental‐scale survey in China and synthesized global o...