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.