Adjusting Rock-Eval® cycle is needed to avoid the need for post-hoc corrections to estimate soil organic (SOC) and inorganic (SIC) carbon. PYRO520 is a cycle with a pyrolysis ending at 520°C instead of 650°C to avoid SIC decomposition while preserving the SOC characterization during pyrolysis. This cycle corrects the misallocation of the end-of-pyrolysis signals and thus repeatably and accurately estimates SOC and SIC contents without using corrections, while preserving the SOC characterization.