Microbial necromass decomposition and stabilization in soilBai

Evidence is emerging that microbial production and residues (necromass) contribute greatly to stable soil organic matter (SOM), which calls for the necessity of separating the microbial necromass from other SOM pools in models. However, the understanding on how microbial necromass stabilizes in soil, especially the mineral protection mechanisms, is still lacking. We conducted a serial of incubation experiments to explore how microbial necromass C and N mineralized. We found microbial necromass N could stabilize in soil more than 20 years. The fungal necromass N could decompose slowly than bacterial and actinobacterial N. We also found temperature could greatly influence on microbial necromass decomposition and production processes. Finally, we found the mineral composition is one of most important factor in regulating necromass retention in soil. Our studies provide more knowledge on how microbial-derived residues contribute to soil organic matter formation.