Some phosphorus detection methods, such as inductively coupled plasma spectrometry (ICP) and spectral radiance, are implemented with the goal of improving the reading accuracy. As per the World Congress of Soil Scientists, the advantages of these specific light-based measurement methods are their evaluation quickness, simultaneous measurements of the nutrients of plant, and their nature of non-destructive testing. Although all these methods contain experimental-based evidence, unanimous method’s approval has not yet been achieved.