Now, a Budget Sensor to Check Soil Moisture in Karnataka

IISc joins hands with IIT to make a device that runs on solar energy and promises to make life easier for farmers.

MALLESWARAM: Researchers at the Indian Institute of Science have come up with a low cost sensor that can accurately determine water content in soil.

They have collaborated with the Indian Institute of Technology, Mumbai, on this project.

Soil moisture plays a critical role in maintaining the overall balance of the earth. It influences rainfall and drought, and determines the movement of nutrients to plant roots.

Almost half of India’s workforce depends on agriculture and allied activities like forestry and fishery. They account for 13.7 per cent of India’s GDP, and have made India one of the largest exporters of farm products.

Since farm output is directly linked to moisture in the soil, an easy-to-use sensor would serve as an essential tool for farmers, scientists say.

The most popular way of finding soil moisture is to measure its ability to store heat. The current sensors, based on “heat pulse,” face two challenges: they are expensive and consume a lot of power.

The IISc-IIT research team has developed a sensor that is cheap and requires little power to run. Powered by a solar cell array, the sensor can work for three days non-stop. “This was achieved with proper materials selection, geometry of the heater probe, and signal conditioning and amplification, and of course through a lot of hard work by my students Nikhil Jorapur and Adhithi Raman,” says Prof G K Anathasuresh, professor of mechanical engineering, Indian Institute of Science.

The electronic integration and interfacing was done by a partnering team from IIT-Bombay, led by Prof Maryam Bhagini.

The researchers calibrated the sensor against white clay, whose properties are well known, and tested it on red soil, commonly found in south India. The sensor can test different kinds of soil and accurately measure moisture up to 30 per cent, which is above the saturation limit for most soils.

The sensor is currently undergoing field trials. It promises to be more affordable to our poor farmers by introducing ‘smart farming’.