IIT Kharagpur, in collaboration with the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, has made a significant breakthrough in soil analysis through the development of diffuse reflectance spectroscopy (DRS) models.

This pioneering technology offers high-throughput soil testing that promises to revolutionize smallholder farming systems by providing faster, cost-effective, and accurate soil health assessments.

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Conventional soil testing methods, which rely on wet chemistry techniques, are not only time-consuming but also expensive when analyzing large numbers of samples. The DRS approach, developed by the agricultural and food engineering (AgFE) department at IIT Kharagpur, addresses these challenges. DRS allows for the rapid measurement of a soil sample’s spectral reflectance in a non-contact, non-invasive manner. The spectral data can then be transformed into multiple soil parameters using pre-calibrated algorithms, eliminating the need for chemical reagents.

According to Professor B S Das of IIT Kharagpur, years of research show that the DRS technology is highly efficient for estimating eight out of 17 soil parameters with up to 80per cent accuracy. Even more impressive, the DRS method can generate soil test crop response (STCR) ratings with an accuracy range of 43 to 100 per cent, closely matching traditional wet chemistry methods. STCR ratings are critical for determining nutrient management strategies, and the rapid nature of DRS makes it a game-changer in large-scale farming.

“This is a great opportunity because most nutrient management strategies are based on STCR ratings, and these ratings may be safely estimated using the DRS approach in a very rapid manner,” Professor Das said. More than 60 per cent of new soil samples were analyzed with over 70 per cent accuracy, which underscores the potential of DRS technology for application at various spatial and temporal scales.

The collaboration with ICRISAT has been instrumental in advancing this innovative solution. “ICRISAT has been at the forefront of global efforts to advance sensor-based technologies,” said Dr. Jacqueline Hughes, Director General of ICRISAT. “Our work with NIRS-based spectroscopy for soil nutrient analysis, combined with IIT Kharagpur’s DRS models, ensures our commitment to providing rapid and cost-effective solutions for resource-poor agricultural systems.”

This technological advancement comes at a critical time, as the IEEE Standards Association is working to standardize soil spectroscopy as a global soil testing method. The ongoing efforts at IIT Kharagpur, particularly with DRS, contribute directly to this initiative, which aims to make soil testing via spectroscopy a viable and accessible solution for millions of smallholder farmers.

The technology offers a promising future for Indian agriculture, aligning with IIT Kharagpur’s long-standing commitment to developing low-cost solutions for improved agricultural practices. By making rapid soil testing accessible, farmers will be better equipped to manage soil health, ultimately leading to better crop yields and more sustainable farming practices.

This breakthrough marks a significant step forward in the adoption of remote sensing technologies for agriculture, paving the way for more efficient and scalable soil testing methods.