Fig. 6: Conceptual framework illustrating mechanisms that control SOC sequestration under film mulching practices.
From: Degradable film mulching increases soil carbon sequestration in major Chinese dryland agroecosystems
(1) Film mulching alters crop productivity and biomass allocation to subsequently influence soil C inputs. (2) Pathway for microbial in vivo turnover. (3) Pathway for microbial ex vivo modification. (4) Accumulation of microbial-derived C. (5) Accumulation of plant-derived C. (6) Changes in SOC, POC, and MAOC. (7) Soil C loss in the context of climate change. Processes (1)–(6) (current stage) were derived from the results of multi-site field trials, while process (7) (future stage) was based on the findings from mesocosm experiments. The aridity index data used in the figure were obtained from the Global Aridity Index and Potential Evapotranspiration Database-Version 3 (Global-AI_PET_v3)29. Solid arrows and dotted arrows signify differences in parameters under PM and DM, respectively, compared with NM. Upward-pointing red arrows indicate increases, whereas downward-pointing blue arrows denote decreases. NM conventional tillage without mulching, PM plastic film mulching, DM degradable film mulching, ABG aboveground biomass, BEG belowground biomass, Rs annual C emissions from soil respiration, Rh annual C emissions from heterotrophic respiration, Ra annual C emissions from autotrophic respiration, Hy-C hydrolytic C-acquiring enzymes, Ox-C oxidative C-acquiring enzymes, CUE microbial C use efficiency, SOC soil organic C, POC particulate organic C, MAOC mineral-associated organic C, dSOC SOC storage in farmland minus SOC storage in the previous year. Source data are provided as a Source Data file. Some elements of this figure were created in BioRender. Xu, Y. (2025) https://BioRender.com/z2vc7lf.
