Across the three rain simulation durations, the area of the dye-stained maize densely-rooted zone increased by 23–32% in FR and more substantially by 76–133% in FMFR, compared to that in FP (Table 3). The dye-stained region matched the maize densely-rooted zone in the FMFR, but this matching was less in the RF and the least in the FP treatment (Fig. 4). This corresponded to an increase in percentage of stained maize densely-rooted zone in the entire stained region in the soil section under FR or FMFR by 24–30% or 76–130%, relative to that under FP (Table 3). The increasing rainfall simulation duration also significantly increased the area of the stained densely-rooted zone in either FP or RF or FMRF treatment; however, the match of simulated rainwater distribution for densely-rooted zone in soil was positively affected by the increasing rainfall duration only in the FMRF treatment (Table 3).