In short
An automatic fertigation system injects fertiliser and acid from concentrated tanks into the irrigation water with dosing pumps or injectors, measures electrical conductivity (EC) and pH in line and corrects dosing to hold the values set by the agronomist. If a probe reads out of range, it stops irrigation and sends an alert.
Components
| Component | Role |
|---|---|
| Stock solution tanks | Concentrated fertilisers kept apart so they do not precipitate, and acid to correct pH. |
| Dosing pumps or injectors | Inject each solution in proportion to irrigation flow. |
| Mixer | Makes sure the solution is uniform before measuring. |
| In-line EC and pH probes | Measure the solution reaching the crop. |
| Controller | Adjusts injection from readings and each zone’s recipe. |
| Flow meter and tank levels | Check what is applied and warn before solution runs out. |
Probe maintenance
- Calibrate pH with buffer solutions and EC with a standard solution as often as the manufacturer advises.
- Clean probes and never let them dry out.
- Compare now and then with a handheld meter.
- Replace pH probes at the end of their limited service life.
Essential alarms
- EC or pH out of range for longer than a set time: irrigation stops and an alert is sent.
- Low tank or dosing pump with no flow.
- Gap between expected and measured flow in a zone.
- Lost communication with a probe.
Recording applications
Spanish rules on sustainable nutrition of agricultural soils require fertiliser applications to be recorded in the farm logbook. An automated system stores the date, zone, volume and values of each irrigation, which makes that record easier. Specific requirements and deadlines are set by the Ministry and the regional government, so confirm them with your adviser.