Fig. 6.Effect
of topsoil depth on enzyme activities in the rhizosphere of maize at the
milk stage (R3), and of soybean at the seed-filling stage (R6) in 2017.
Values with means ± standard error (n=3). Within each panel, values with
a same letter are not significantly different at P >
0.05 among treatments in two crops (2-way ANOVA).
Table S1. The effect of topsoil depth on the concentrations of
N, P and K in root, stem and leaves 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). Values with a same letter are not significantly different between
topsoil depths (P > 0.05).