Definition
Fertigation combines irrigation and fertilization. Soluble fertilizer is carried with the irrigation water to the crop root zone, so water and nutrients arrive together and only as needed. It uses methods such as drip irrigation and sprinkler irrigation, and it watches EC, pH, and soil moisture. The aim is to save water and fertilizer while raising quality and efficiency. It is one of the core techniques of precision agriculture.
System Composition of Fertigation
A fertigation system includes the water source and filtration, mixing and injection (a Venturi, a proportional pump, or a fertilizer tank), the pipe network (drip tape or pipe and sprinkler heads), and control and monitoring (sensors, a controller, and a cloud platform). EC, the electrical conductivity that reflects solution strength, and pH are measured continuously, and the system can change the injection ratio so the irrigation solution matches what the crop needs.
Application of the Internet of Things in Fertigation
IoT moves fertigation from fixed time and fixed dose toward decisions based on need. Soil moisture, temperature and humidity, EC, pH, and other sensors collect field data. Together with remote sensing and weather data, machine learning or a rules engine produces an irrigation decision. The controller opens and closes valves and pumps and sets the injection ratio. The data goes to a cloud platform for remote monitoring, history, and traceability records. SimtoLink can supply the sensors, gateway, and API for a fertigation system.
Application Scenarios and Implementation Recommendations
Fertigation is used in greenhouse vegetables, orchards, field crops, and flowers. A project has to judge source-water quality and filtration, the crop's fertilizer demand through the season, the irrigation already in place, and power and communications. A sound start is EC and pH monitoring with manual or semi-automatic control, then artificial intelligence decisions after enough data has accumulated. Where organic certification or green certification applies, the fertilizer itself has to be allowed, and residues have to be controlled.
Solution strength and arrival at the root zone
Fertigation sends soluble fertilizer into irrigation water at a target concentration, then the irrigation system carries it to the root zone. Three things have to hold at once. The mix ratio is correct. Conductivity and acidity after mixing fall in the target range. Water and nutrients actually reach the roots, rather than stopping in the pipe or only wetting the surface. A dosing pump, a Venturi, or a fertilizer tank sets the injection ratio. It does not by itself guarantee the concentration at the roots. If filtration and irrigation uniformity are not enough, the recipe at the head is right and the field is still uneven.
Fertilizer has to dissolve fully. Water quality and the filter have to stop undissolved particles. The irrigation schedule has to match the crop's stage. Target concentration should be controlled on the irrigation solution, not on the stock tank, and the crop and growth stage should be stated. The sample point sits after mixing is uniform. Pressure in each irrigation zone has to be stable. Otherwise the same recipe delivers different volumes, and nutrients differ with them. Production that places extra limits on fertilizer type should exclude those materials when the recipe is written, not explain them after a residue result comes back.
Dosing by time is a common error. After pressure or flow changes, the same ten seconds of injection changes the fertilizer amount, and root-zone concentration shifts with it. Fertilizer that enters the network before it has dissolved raises conductivity for a short time, then precipitates and blocks emitters. Measuring conductivity once in the fertilizer tank, and treating that as the whole field having reached the target, is the same mistake. Adjusting acidity and conductivity separately makes them pull on each other. Adding acid raises conductivity, and the system compensates back and forth. Using the daytime target concentration at night, when the crop takes up nutrients differently, lets salt accumulate in the root zone.
Data at the head also cannot replace data at the root zone. A passing result at the head only means the ratio has started. A blocked end, a leaking branch, and salt already in the soil all change conditions around the roots. Take one sample after mixing and one in a typical zone, and compare them with the inline instrument. Check them together with uniformity of drip irrigation and temperature compensation of EC value. Otherwise the controller shows a closed loop, and the field did not receive the same concentration.
After a zone valve closes, fertilizer solution left in the pipe is pushed out first the next time the valve opens. If the next zone is a different crop, that residual carries the previous recipe into the new zone. Before switching, flush the residual with clear water, and record how long the flush takes. Without that step, the recipe at the head has already changed, and the end is still receiving the previous concentration.
When the stock tank level is too low, the injector draws air, and the conductivity reading jumps. If the controller treats those jumps as the true concentration and adjusts, it over-applies fertilizer once the level recovers, and salt in the root zone rises with it.
The volume of the clear-water flush should also count in this cycle's irrigation quota. Otherwise the fertilizer concentration is right, the total water is counted twice, and the root zone receives more water than planned.