Use of organic substrates for increasing soil organic matter quality and carbon sequestration of tropical degraded soil: a 3-year mesocosms experiment

Background: Exogenous organic matter may be valuable amendments for degraded tropical soil in Northern Vietnam. Their effect on carbon storage and composition need to be evaluated.Method: The study investigates soil from mesocosms cultivated with maize and amended with four different kinds of amendments: only mineral fertilizers (control), buffalo manure, compost or vermicompost as well as biochar.Results: All organic amendments showed a positive effect on soil carbon storage and significantly influenced soil organic matter quality. The presence of biochar increased lignin-derived compounds abundance as well as both plant and microbial sugar content of soil amended with vermicompost but had no effect in the case of control soil.Conclusion: Synergistic effects between plants and different organic amendments influence carbon storage and soil organic matter composition.