Root impacts on litter C and N transformations did not depend on fertilization
Root ingrowth core treatments and fertilization treatments both altered the fate of litter C and N in SOM, but the root effect did not depend on fertilization. All p-values for ingrowth core treatment x fertilization treatment interactions are above 0.05 (SI Table 2) and root biomass did not vary across fertilization treatment (SI Fig. 4a). As such, subsequent data shown for each factor are aggregated over the other factor.