Researcher Sanjeewa Jayarathne from the University of Peradeniya conducts research studies on the soil carbon matter of the project.

Research Methodology – Soil

The Walkley-Black (WB) method (Walkley and Black, 1934) determines soil organic carbon (OC) by oxidizing carbon with acidic dichromate (Cr2O72–). This method quantifies the amount of oxidizable organic matter in which OM is oxidized with a known amount of chromate in the presence of sulfuric acid. The oxidation step is followed by titration of excess dichromate with ferrous sulfate. The OC is calculated from the difference between the total dichromate added and the amount of dichromate left unreacted after OC oxidation. The method provides an estimate of soil OM from 

OC determination with assumptions on the fraction of soil OC reacted and the amount of OC in soil OM.

This method was widely considered a standard method for OM after its development, but the advent of thermal decomposition instruments has resulted in its limited use. Also, loss on ignition and thermal decomposition methods are more widely used due to their ability to analyze samples in a more time efficient manner.