The peats of the Jambi region of Sumatra have been cultivated for many years by the villagers, after minor draining works. Their humification process was investigated using a chronosequence: T0 (control soil), 3 years, 6 years and 9 years of cultivation. The extraction of the humic substances at different pH reveals that the pH 12 extractant gives rise to false conclusions concerning the polymerized nature of the humic acids extracted. Elemental and molecular analyses confirmed their aliphatic nature, and hence their neoformed character.