Fractional and group composition of organic matter in virgin and reclaimedpeat soils

The fractional and group composition of organic matter in peat soils of lon g-term agricultural experiments at the Polesie, Minsk, Ivantsevich, and Sar ny experimental stations was studied. It is shown that the group compositio n of organic matter in reclaimed peat soils mainly depends on the geobotani c nature of peat and varies slightly during agricultural use. On the contra ry, the fractional composition of humic acids changes considerably. Soils a re enriched with a biochemically stable fraction extracted with sodium pyro phosphate and are depleted of a biochemically less stable fraction addition ally extracted with alkali.