| Abstract: | A system is described for growing plants in flowing solutionin which the concentration (activity) of some nutrient ionsis continuously monitored and held almost constant by meansof ion-selective electrodes which control the operation of nutrientpumps. By recording the concentration of a given ion in theflowing nutrient solution and the amount of that ion which isdelivered by the nutrient pumps, it is possible to follow nutrientuptake over long and short periods. A brief account is givenof the operation of the system using a nitrate ion-selectiveelectrode to examine aspects of  uptake by perennial ryegrass (Lolium perenne L.). |
