I. Th.H. Gieling, Ing. E. van Os, Dr. A. de Jager
On a large scale growers are switching over to soilless cultures in greenhouses. Especially the open-drain version of growing on substrates is often applied. The open-drain system has several disadvantages, which can be circumvented by re-catching and re-using the drain water (closed-loop system). A closed-loop system can offer several advantages, such as less pollution of the environment and better quality control facilities.

In a closed-loop system each nutrient is measured and dispensed separately, hence the concentration of each nutrient in the total nutrient solution has to be determined by special sensors. However, the existing measuring methods are not practicable for horticultural use, which stresses the need for a new generation of sensors.

Promising new techniques, which use the ISFET (ion-selective field effect transistor) semiconductor for sensing, are being developed in the Netherlands, the USA and especially in Japan.

Gieling, I. Th.H., van Os, Ing. E. and de Jager, Dr. A. (1988). THE APPLICATION OF CHEMO-SENSORS AND BIO-SENSORS FOR SOILLESS CULTURES. Acta Hortic. 230, 357-362
DOI: 10.17660/ActaHortic.1988.230.47

Acta Horticulturae