Organic matter in the peaty-podzolic-gley soils of Yaroslavl Oblast and its changes upon drainage.

Changes in the composition of organic matter in the peat horizon of peaty podzolic-gley soils upon their artificial drainage were studied, and a minor increase in the share of humic acids associated with the transformation of organic matter was found. Drainage decreases the content of carbohydrates in the fractions of humus acids. The humification index of peat is more fitted with the degree of decomposition of peat than the C ha /C total value and can be used for the evaluation of the humus status of peaty soils.