ISHS Acta Horticulturae 507: III International Workshop on Models for Plant Growth and Control of the Shoot and Root Environments in Greenhouses
OPTIMISATION OF WATER AND NUTRIENT DOSING BY MODELLING AND USING FEEDBACK CONTROL MEASURES |
| Authors: | H.-P. Liebig, F. Lippert |
| Keywords: | Fertigation, Cucumber, Tomato, Sweet Pepper, Control system |
| Abstract:
To increase water and fertiliser use efficiency and to reduce negative impacts on the environment a control system for summer season crops in unheated glasshouses growing in soil was developed. Based on SUCROS (Simple and Universal CROp growth Simulator) biomass production was modelled by adaptations for cucumber. For tomato and sweet pepper biomass production was modelled using growth curves so far. Feedback signals of the soil water status are simply to be obtained but proper on-line measurements for the nutritional status are not available and time series of soil analysis are necessary. In contrast to soil status plant status parameters are lacking in most control systems. The objective of the research was to develop and to validate the control system. One special objective was to examine the suitablity of stem length as feedback signal for the control system in a series of experiments with cucumber, tomato and sweet pepper. The correlation between biomass production estimation by models and stem length can be used to adjust the growth model and the relation between the uptake of N, Ca, Mg, K, P and stem length can be used to estimate the fertiliser demand per cm length growth. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
