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New Discovery in Rapid Soil Testing for Smallholder Farms Using Diffuse Reflectance Spectroscopy

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.

Locations of soil samples collected from selected districts of the Bundelkhand region during 2018 (open circles) and 2021 (plus sign).
Locations of soil samples collected from selected districts of the Bundelkhand region during 2018 (open circles) and 2021 (plus sign).

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.

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This work aligns with SDG 17.
This work aligns with SDG 17. ​ ​

For media inquiries, please contact:

Parkavi Kumar
Parkavi Kumar Senior Communications Specialist – Asia

 

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About The International Crops Research Institute for the Semi-Arid Tropics

The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) is a pioneering International Organization committed to developing and improving dryland farming and agri-food systems to address the challenges of hunger, malnutrition, poverty, and environmental degradation affecting the 2.1 billion people residing in the drylands of Asia, Sub-Saharan Africa, and beyond.

ICRISAT was established under a Memorandum of Agreement between the Government of India and the CGIAR on the 28 March 1972. In accordance with the Headquarters Agreement, the Government of India has extended the status of a specified “International Organisation” to ICRISAT under section 3 of the United Nations (Privileges and Immunities) Act, 1947 of the Republic of India through Extraordinary Gazette Notification No. UI/222(66)/71, dated 28 October 1972, issued by the Ministry of External Affairs, Government of India.

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The International Crops Research Institute for the Semi-Arid Tropics
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