The EPR spectra of plowed Dark Gray Forest soil, plowed Chernozem and virgin and plowed Sod-Podzolic soils contain not only the previously observed signal with a g factor of 2.003 from the paramagnetic centers of humus compounds, but also two other signals with g factors of 2.002 and 2.008, which were observed for the first time, indicating the presence of three different typs of paramagnetic centers in the soils studied. -Journal summary