Differences in the regulation of soil carbon quality and stability by topsoil and deep soil under grazing - Jiali Sun; Shichao Tian; Haihua Bai; Ahmed F. El‑Shafie; Mohamed E. Abuarab; Ali Mokhtar; Zifeng Zhao; Xiaomeng Guo; Wei Qin; Fei Li (Agriculture, Ecosystems & Environment, 2026)