ISHS Acta Horticulturae 562: III International Symposium on Sensors in Horticulture
FEEDBACK CONTROL OF WATER SUPPLY IN AN NFT GROWING SYSTEM |
| Authors: | TH.H. Gieling, H.J.J. Janssen, H.C. de Vree, P. Loef |
| Keywords: | constant drain return, tipping bucket flow sensor |
| Abstract:
The paper explores a concept of irrigation control, where the supply of nutrient solution is controlled without the use of predictive uptake models but rather by the use of a direct feedback of a drain flow measurement. This concept proves to be a viable approach. Results are presented, showing the compensation of changes in water up-take due to variations in global radiation, with a very tight control of the drain flow, keeping it constant over long periods of time. A tipping-bucket type flow sensor and its use in controlled water supply to a to-mato crop is described. A calibration procedure for the tipping-bucket instrument is presented. | |
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