Fertigation and Irrigation Triggering
Fertigation and irrigation triggering in Hydria 8++ Touch happens by means of the following:
1. Time triggerings; these can be fixed triggerings on a preset time-of-the-day basis or interval triggerings, i.e. triggerings that happen every one hour within a specific time period (e.g. from 9:00 until 16:00),
2. External triggerings; these are controlled by external sensors (safety limits and time delays apply to this category). External triggerings can be further categorised under simple external triggerings (initiation of the irrigation/fertigation program), and plant-nursery type external triggerings, which are specifically designed for the filling of nutrient solution tanks, where both the initiation and termination of the filling process are controlled by an external sensor (e.g. nutrient level relay),
3. Solar radiation-based triggerings; with the addition of a light meter, we have the option to control the irrigation frequency based on the level of solar radiation in the greenhouse. In other words, irrigation triggering happens based on the integration of solar radiation. Practically, this means that the irrigation of the crop will be more frequent on a sunny day as opposed to a cloudy day. This method of irrigation management may have a flaw; if the system is set (as far as the the desired drainage percentage is concerned) under conditions of low light intensity, then it will irrigate the crop excessively when the light intensity increases. The opposite will happen if the system is set under conditions of high light intensity. This issue is addressed in Hydria 8++ Touch, by employing an additional balance parameter, easily adjustable by the user. As far as the solar-based irrigation management is concerned though, the superiority of Hydria 8++ Touch compared to competitor fertigation systems, is not what has already been mentioned. As we know the desired electrical conductivity (EC) value of the fertigation solution changes depending on the light intensity. We also know that even the desired ratios among different nutrients change depending on the light intensity. Competitor systems suffice to introduce a slight reduction in the EC value, under conditions of high light intensity. In contrast, in Hydria 8++ Touch, this issue is solved in a more complete fashion. The mean light intensity value over a time course chosen by the user (e.g. 15 minutes) is logged. This mean value is stored into the memory of Hydria 8++ Touch and it is constantly recalculated. Hence, whenever there is a command for irrigation triggering either based on the program of solar radiation integration or any external sensor, the fertigation system will check the stored mean light intensity value. If this value is lower than the preset one, then the irrigation will be executed normally. However, if this value is higher than the preset one, then a different -and of course preset by the user- irrigation program will be executed instead, in which all irrigation parameters can be individually controlled. In other words, we can irrigate using a different EC and acidity (pH) value, fertiliser ratio and volume (or time duration). The most important is that all these features can be easily accessed through the user-friendly English menu featured in Hydria 8++ Touch.