ISHS Acta Horticulturae 304: I International Workshop on Sensors in Horticulture
SENSORS IN RECIRCULATING NUTRIENT SOLUTION SYSTEMS |
| Author: | B. Vestergard |
| Abstract:
In order to avoid serious pathogen problems in hydroponic plant growing systems 3 methods for supplying nutrient solution to a system are commonly used.
As 1 and 2 soon will be illegal to use because of the strong environmental pollution which is the results of these systems, only 3 remains open to commercial growers. A special variation of 3 is the SPF system (SPF = specific pathogen free) and it is the sensors from such a system that will be presented here. A DFT (DFT = deep flow technique) and a NFT (NFT = nutrient flow technique) system with a 100% recirculating nutrient solution were build and tested under actual growing conditions in order to see how pathogens would develop in the root zone. The system provided for the removal of all root exudates measured as TOC (TOC = total organic carbon) and further demonstrated a sterilizing/oxidizing system using a combination of ozone, UV and hydrogenperoxide. A BAC filter (BAC = bacteriological activated carbon) was added and a number of electrodes were tested for reliability and stability. All electrode measurements were checked in a laboratory in order to verify their accuracy. | |
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