Fig. 5.

Typical plots obtained from simulation for the saturated case (1A–E). and the partially saturated case (2A–E). The five images in each case correspond to $\theta =0.2{\theta }_{max}=\pi /5,$ and $h=0.2h_{max}=0.36mm$ for (A) $r=0.2r_{max}=0.352mm\text{,}$ (B) $r=0.4r_{max}=0.704mm,$ (C) $r=0.6r_{max}=1.056mm\text{,}$ (D) $r=0.8r_{max}=1.408mm\text{,}$ and (E) $r=1.0r_{max}=1.76mm\text{.}$ The streamlines show the effective diffusion paths, with red corresponding to high nutrient concentration and blue corresponding to lower nutrient concentration. (This figure is available in colour at JXB online.)