New Discovery in Rapid Soil Testing for Smallholder Farms Using Diffuse Reflectance Spectroscopy
Joint IIT Kharagpur/ICRISAT Media Release
A recent study by the Indian Institute of Technology (IIT) Kharagpur, in collaboration with the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, has developed and validated the efficiency of Diffuse Reflectance Spectroscopy (DRS) models for high-throughput soil analysis with impact at scale in smallholder systems.
Decades of research at the Agricultural and Food Engineering (AgFE) Department of IIT Kharagpur show that DRS may be safely used for rapid soil assessment.
Conventional soil testing laboratories use wet chemistry-based soil testing methods that are time-consuming and can become expensive when a large number of samples need to be analyzed. On the other hand, the spectral reflectance of a soil sample can be rapidly measured in a non-contact mode, and the results can be transformed to multiple soil parameters using calibrated spectral algorithms.
Once the DRS algorithms are developed for a region, they may be used to analyze soil samples collected from different fields and at different sampling times. The technology is rapid, noninvasive, and involves no chemical use for estimating multiple soil parameters.
The DRS approach was shown to be effective for estimating 8 out of 17 soil parameters with as high as 80% accuracy. Specifically, the soil test crop response (STCR) ratings estimated through the DRS approach matched the wet chemistry-based STCR ratings to the tune of 43 to 100%.
“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,” said Professor B. S. Das from IIT Kharagpur. "More than 60% of the new samples estimated over 70% accuracy, which indicates a huge opportunity to apply the DRS technique at different spatial and temporal scales. The partnership with ICRISAT has been very productive in developing these innovative methods for rapid soil health assessment."
"ICRISAT has been at the forefront of global efforts to advance sensor-based technologies," emphasized Dr Jacqueline Hughes, Director General of ICRISAT. "Our recent work with NIRS-based spectroscopy for soil nutrient analysis, paired with this pioneering research towards DRS models for soil analysis, ensures our commitment to deliver rapid and cost-effective alternatives to resource-poor agriculture systems.”
As the IEEE Standards Association embarks on standardizing soil spectroscopy as a standard method of soil testing (P4005 - Standards and protocols for soil spectroscopy), the efforts at IIT Kharagpur and ICRISAT signify a step forward in making soil testing through reflectance spectroscopy a reality.
For media inquiries, please contact:
