A model to calculate the uptake by a developing root system or root hair system of solutes with concentration variable diffusion coefficients

Summary Two modifications to a method for calculating the uptake of solutes by a developing root system are presented. The method is investigated in the cases which would give rise to the greatest error, and this was found to be less than 10 per cent. The modifications may be of particular interest in studies of the absorption of phosphate and potassium from soils. Paper No. IV: Uptake of solute by multiple root systems in soil. Paper No. IV: Uptake of solute by multiple root systems in soil.