An empirical model to simulate sodium absorption in roses growing in a hydroponic system

Modelling nutrient absorption can contribute to the management of hi-tech cultivation systems in greenhouse horticultural production. Nevertheless, previous studies to understand the kinetics of nutrient absorption, rarely take into consideration the accumulation of salt ions in the nutrient solution. In this project we develop and validate an empirical model for sodium uptake concentration in hydroponic rose (Rosa spp. cv. Kardinal) production. Model development and validation was conducted using a series of experiments in both greenhouse and growth chamber conditions. The model framework takes into account plant developmental stage and external sodium concentration. While model calibration data were collected at levels of sodium up to 40 mol m(3) NaCl as root environment salt concentration, model validation was carried out at lower ranges. The proposed model not only shows a high predictive capability, but also provides useful output parameters such as electrical conductivity, which is the main parameter currently monitored for managing nutrient solution in greenhouse Cultivation. Incorporated as part of a larger DSS, our model can be used to improve nutrient Solution management in production regions that do not have economically valid alternatives other than the use of poor quality (saline) irrigation water. (C) 2008 Elsevier B.V. All rights reserved.