Figure 5.
Effect of changing values of model inputs for the external efficiency of active (εa) and mature (εm) roots on P uptake and total dry matter. Bars represent measured values and black circles are simulation outputs of the three-step base model (εa = 0.14 and εm = 0.025 μg P cm-2). Squares represent model predictions under the assumption that the contribution of mature roots to P uptake is small (εm = 0.001 μg P cm-2), triangles show predictions if mature roots contribute much (εm = 0.05 μg P cm-2).