Ahamadou, Bocar, Qiaoyun Huang, Lin Yaping, and Javed Iqbal. “Humic Substances As Indicator of Sustainable Crop Management Practices of Ultisols in Southern China”. Research Highlights in Agricultural Sciences Vol. 6 (December 8, 2022): 94–115. Accessed June 13, 2026. https://stm.bookpi.org/RHAS-V6/article/view/8849.