Smart irrigation
Smart irrigation: what it is, how it works and how to get started
A smart irrigation system decides when and how much to water from soil, weather and crop data instead of a fixed schedule. The components it needs, how it makes decisions and how to roll it out safely.
In short
- Smart irrigation replaces the fixed schedule with decisions based on data: soil moisture, weather, crop status and the condition of the irrigation system.
- It has four parts: sensors, connectivity, a platform that interprets the data and actuators (valves and pumps).
- The core logic is to keep the soil between field capacity and the refill point: never watering too early, never letting the crop struggle.
- The safe way to start is to measure and alert first, and automate valves once you trust the data.
What is smart irrigation?#
Smart irrigation is a system that decides when and how much to water from data measured in the field, instead of following a fixed schedule or gut feeling. A timer waters on Tuesday at 6 a.m. even if it rained on Monday; a smart system checks the soil and the weather, and waters only if the crop needs it.
It matters because water is agriculture's most contested input: according to FAO AQUASTAT data, agriculture accounts for about 70% of the freshwater withdrawn worldwide. Every unnecessary irrigation is water, pumping energy and leached fertilizer; every late one is lost yield.
Components of a smart irrigation system#
Every system, from a greenhouse to hundreds of hectares, shares four parts:
Sensors. They measure what matters for the decision: soil moisture, line pressure and flow, and weather. Pressure is what catches faults: a leak or a clogged emitter.
Connectivity. It carries the data from the field to the cloud. LoRaWAN is the usual choice in open fields thanks to its long range and low power; Wi-Fi and cellular work where there is coverage.
Platform. It stores the data, compares it with thresholds per zone and crop, and turns readings into decisions and alerts growers understand.
Actuators. Solenoid valves and pump controllers that run the irrigation — manually, on a schedule or automatically.
Types of smart irrigation: weather, soil and satellite#
| Approach | How it decides | Strength | Limit |
|---|---|---|---|
| Weather-based (ET) | Estimates crop water use from evapotranspiration and subtracts rainfall | Nothing to install in the soil | Estimates rather than measures; blind to differences within the field |
| Soil moisture-based | Irrigates at the refill point and stops near field capacity | Measures what the roots actually have | Each sensor is one point; placement matters |
| Satellite-assisted | Flags stressed zones across the field with indices like NDMI | Covers the whole field, no installation | Images every few days, subject to clouds |
The strongest systems combine all three: weather anticipates demand, soil confirms when to irrigate and satellite shows where to look. We cover it in depth in NDMI vs NDVI.
How it decides when and how much to irrigate#
The foundation is the soil water balance. After a heavy irrigation the soil drains the excess and settles at field capacity: the most water it can hold. As the crop uses water, moisture drops. The goal is to irrigate before it reaches the refill point, the level below which the plant starts working harder to extract water.
Both thresholds depend on the soil (sand holds far less than clay) and on the crop and its growth stage. That is why copying values from the internet doesn't work: they are calibrated on each field by watching how the sensor responds to irrigation.
How to implement smart irrigation step by step#
Split the field into uniform zones. Same soil, same crop and same irrigation block. Each zone needs its own measurement.
Measure before you automate. Install moisture and pressure sensors and record a few weeks of baseline under your current practice.
Set thresholds per zone. Field capacity and refill point from what you observed, not from a generic table.
Start with alerts. Let the system tell you when to irrigate and when something fails. You decide and compare with the result.
Automate once you trust the data. Connect valves zone by zone, with safety limits and a review whenever the crop changes stage.
Design for failure: if a sensor stops reporting or the connection drops, the valve must fall back to a safe state and the system must alert you. Unsupervised automatic irrigation can cost more than the schedule it replaces.
Common mistakes when automating irrigation#
- One sensor for the whole field. A single point can't represent different soils or blocks.
- Copied thresholds. Values depend on soil and crop; calibrate them on your field.
- Measuring the soil but not the system. Without pressure or flow, a leak looks like a water shortage and the system irrigates more.
- Automating without reliable connectivity. Make sure the data always arrives first.
That is how Bloomiot Workspace works: it joins soil moisture, line pressure and satellite data, sends alerts in plain language and works with your own LoRaWAN or MQTT sensors. See how it catches faults in leak detection or how to connect your devices in the documentation.
Frequently asked questions
What is a smart irrigation system?
It is a system that decides when and how much to irrigate from field data such as soil moisture, weather and crop status, instead of a fixed schedule. It combines sensors, connectivity, a platform that interprets the data and valves that run the irrigation.
How much water does smart irrigation save?
It depends on how you irrigate today. Savings come from not irrigating when the soil already has water and from catching leaks early. The right way to know is to record a baseline under your current practice and compare it after implementing the system.
Do I need internet across the whole field?
No. With LoRaWAN, sensors talk by radio to a gateway that can be several kilometers away depending on terrain. Only the gateway needs an internet uplink, over Wi-Fi, cellular or cable.
Can I use the sensors I already have?
Often yes, if they speak a standard protocol such as LoRaWAN or MQTT. Bloomiot Workspace is designed to work with third-party hardware, without forcing you to replace what you already installed.
Sources
- Smart irrigation
- IoT
- LoRaWAN
- Soil moisture
- Automation
About the author
Elio Fagúndez
Founder of Bloomiot. Mechatronics engineer specializing in hardware development, embedded systems and IoT; he designed the platform that turns satellite and field data into irrigation decisions.