Changes in the Ions

1. The concentration of potassium, phosphate and nitrate declined significantly in the bathing medium within four days.
2. The concentration of sodium and sulphate, however, increased indicating that water was absorbed faster than either of the two ions, or possibly they leach out.
3. The rate of uptake especially of potassium and calcium differed between the two plant species, maize and bean.
4. The ion concentration (particularly of K⁺, NO^-₃ and SO^2-₄) in the root was considerably higher than in the nutrient solution used for the experiment.