Can Soil Sensors Tell Farmers When to Irrigate? How Smart Irrigation Works

Farmers often irrigate fields according to a fixed schedule. But soil does not always need the same amount of water every day. New sensor-based systems can measure soil moisture and help farmers decide when irrigation is actually needed. This can reduce unnecessary watering and improve the use of limited groundwater.

How Do Soil Sensors Work?

A soil-moisture sensor is placed inside the field at a suitable depth. It measures the amount of moisture around the plant roots and sends the information to a device or mobile application. Farmers can then use the data to decide when irrigation should begin.

ICAR has developed an IoT-enabled soil monitoring system at its Research Complex for the Eastern Region in Patna. The system was designed to address problems including erratic rainfall, falling groundwater levels, rising irrigation energy costs and inefficient water application.

Some systems can send information remotely. This means farmers do not always need to visit the field simply to check soil moisture. The technology can be particularly useful where fields are scattered or irrigation decisions are difficult to make from visual observation alone.

Water is becoming a bigger concern for many farmers. In 2026, uneven monsoon rainfall has affected several parts of India. A weak September could also leave less moisture in the soil before farmers begin preparing for rabi crops.

When farmers irrigate without checking soil conditions, they may apply water even when enough moisture remains around the roots. This can waste water and increase electricity or diesel costs. In areas with limited groundwater, repeated unnecessary irrigation can also increase pressure on available resources.

Sensor-based irrigation offers a different approach. Instead of asking, “When did I last irrigate?” the farmer can ask, “Does the soil need water now?”

How Much Water Can It Save?

The savings depend on the crop, soil, irrigation method and local conditions. ICAR lists an IoT-enabled soil-moisture sensing system for irrigation scheduling that can save around 10–15% water compared with traditional irrigation scheduling.

Research on banana cultivation has also tested IoT moisture sensors for automated irrigation. The study reported a 25–30% reduction in water use and a 15–20% reduction in nutrient application without reducing yield under the tested conditions.

These figures should not be treated as guaranteed savings for every farm. Soil type, crop stage and irrigation system can change the results. Farmers should test the technology under local conditions before investing heavily.

Not necessarily. Farmers can start with a basic soil-moisture indicator rather than installing a fully automated irrigation network. ICAR also lists a simple electronic soil-moisture indicator designed to help farmers schedule irrigation.

A more advanced system can connect sensors with pumps, valves and mobile applications. Such systems can automatically start or stop irrigation when moisture reaches a defined level. But they require higher investment, reliable electricity or solar power and technical support.

For small farms, a shared system may make more sense. An FPO, cooperative or Custom Hiring Centre could purchase equipment and offer soil-monitoring or irrigation services to several farmers.

Technology works best when farmers understand what the data means. A sensor reading alone does not explain every crop problem. Farmers still need to consider rainfall forecasts, crop growth stage, soil type and irrigation method.

The sensor should therefore support decisions rather than replace them. Farmers can combine soil-moisture information with local weather advisories and field observations. This gives a better picture of whether irrigation is needed.

Farmers should also place sensors correctly. A sensor installed too close to the surface may not represent moisture available to deeper roots. The installation depth should match the crop’s root zone and the purpose of monitoring.

What Should Farmers Check Before Buying?

Before purchasing a soil-monitoring system, farmers should ask about sensor accuracy, battery life, connectivity, installation depth, maintenance and replacement costs. They should also check whether local technicians can repair the equipment.

Farmers should calculate the expected benefit before investing. If the system saves only a small amount of water but costs more than the resulting savings, it may not make financial sense.

For larger farms, horticulture and water-stressed areas, the economics may be stronger. Small farmers can consider sharing the equipment through an FPO or hiring a service instead of purchasing the complete system.

ICAR is already working on precision agriculture using sensors, drones, satellites, AI and other digital tools. Its national precision agriculture programme includes sensor-based irrigation, soil monitoring and digital decision-support systems for Indian farming conditions.

As rainfall becomes less predictable and irrigation costs rise, that answer can help farmers avoid unnecessary watering, protect groundwater and use energy more carefully. The technology is most useful when it is affordable, locally supported and combined with good farming decisions.