ISHS Acta Horticulturae 481: International Symposium on Growing Media and Hydroponics
PLANT NUTRITION MANAGEMENT: PRESENTATION OF A NUTRIENT DELIVERY SYSTEM CONNECTED TO REAL GROWTH |
| Authors: | P. Chagvardieff, M. Pean, C. Ravel, J.C. Vidal |
| Keywords: | Triticum aestivum, CO assimilation, carbon/nitrogen ratio, AMAC system |
| Abstract:
Nutrient solution recycling must compensate uptake of minerals by plants. A method of nutrient supply using the concept of dose instead of the control of concentration by electrical conductivity (EC) was introduced by Ingestad (1982), in which the amount added during a certain time interval is calculated from the Relative Growth Rate, and the uptake of nutrients (Relative Addition Rate). We propose a new principle where the driving force of the system is the regulation of Carbon/Nitrogen ratio. The carbon assimilated is measured by pulses added to compensate photosynthesis m the closed chambers; a pump is connected to add the amount of nitrogen, and proportionally other ions, to a C/N ratio fixed by the experimenter. Feasibility of the method is shown. Effects on ions uptake and growth are presented, with increased consumption of N, P and K and stimulated growth for the same C/N value as in EC regulation. | |
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