Fig. 1.

Simulated root systems (3-D architture) from CRootBox of upland rice grown on a P-deficient soil with three P treatments in the topsoil [no P amendment (NoP), a sub-optimal rate (SubP) and a non-limiting rate (PlusP)] and two water regimes (field capacity (FC) and drying periods (DP)]. The colour of the root represents the P uptake rate of the root, while the colour on the discs represents the soil P sink. The transition between topsoil and sub-soil (at 20 cm depth) can be observed by the shift in P uptake rate in SubP and PlusP.