Table S2 . Soil C/N ratios, microbial biomass C (MBC), microbial biomass N (MBN), DOC, and NH4+ at days 3, 12, and 45 during the 45-day incubation period. C-only represents addition of C substrates glucose and oxalic acid only; CN6, CN10, and CN80 represent addition of C substrates glucose and oxalic acid as well as the N substrate alanine at different C/N stoichiometries of CN6, CN10, and CN80, respectively. Different letters indicate significant differences among stoichiometric ratios at the end of cumulative CO2 emission (one-way ANOVA and LSD test; P< 0.05 level). Values represent means + standard errors (n = 4).