AbstractThe application of various methods of data processing of a raw, untreated free induction decay (FID) to improve the quality of noisy and overcrowded spectra is shown. The use of complex interpolation of fragments of a typical31P NMR spectrum of humic substances from forest soil in D2O, combined with two‐stage apodization of the FID, results in better defined signals and a higher accuracy of the integration of signals partially overlapped in the initial spectrum. Convolution difference resolution enhancement was used to enhance the spectral resolution of overlapped orthophosphate ion and orthophosphate monoester signals, while the noise was attenuated by a decreasing exponential.An attempt to detect carbon signals buried in the noise by applying a rapidly decaying exponential (line broadening of 10 or 50 Hz) to a noisy FID, and the use of resolution enhancement, are also described for the13C NMR signals from soil extract