The lack of adequate access to effective soil fertility testing in India, and much of the subtropical and tropical world, has led a group of scientists to explore how a smartphone camera might be transformed into a powerful and readily available alternative. Recently published in the Elsevier journal Biosystems Engineering, the research team describes important advances in the area of image-based soil organic matter (SOM) assessment and how it can streamline the process of evaluating soil fertility.
source https://phys.org/news/2021-08-smartphone-cameras-smallholder-farmers-access.html