Fig. S1. Effect of topsoil depth on N, P and K uptake in root
of maize at the jointing (V7) and milk (R3) stages, and of soybean at
the initial flowering (R1) and seed-filling (R6) stages in 2017. Values
with means ± standard error (n=3). Within a growth stage of each panel,
values with a same letter are not significantly different (P> 0.05).