Improved estimation of soil organic carbon stock in subtropical cropland of Southern China based on digital soil mapping and multi-sources data. - Bifeng Hu; Qian Zhu; Modian Xie; Yibo Geng; Yali Wen; Shuhan Peng; Yanru Qiu; Xiya Jin; Pengbo Zhang; Hongyi Li; Zhou Shi (Geo spatial Inf. Sci., 2025)