A field model experiment on stimulating the activity of native oil microorganisms–decomposers was performed on an oil-polluted area in a high-moor bog under its total flooding in the northern taiga (Western Siberia). For two summer months, the doses of lime and nitrogen, phosphorus, and potassium fertilizers applied have caused a decrease in the oil products (OP) content by 54% relative to their initial amount. The decrease of the OP content in the soil profiles was nonuniform, and at the depth of 30–50 cm it was accompanied by the acidification of peat. The stimulation of the activity of aboriginal microorganisms by applying lime and mineral fertilizers led to the development of migration processes with the participation of oil and products of its transformation. These processes differed from those in the soil without application of lime and fertilizers. An original technology of applying lime and fertilizers providing minimal disturbances the upper 50-cm peat layer is suggested.

The mineralization rate of the 14 C-labeled organic matter (OM) in the humus-accumulative AE horizon of a soddy-podzolic soil was determined in a laboratory experiment. The labeling was performed in a field experiment when microamounts of 14 C-labeled glucose, glycine, and uracil were added to tree waste in sacks embedded in the upper layer of the forest litter. Samples containing 14 C were taken from the AE horizon (above which the sacks with the labeled material were placed) 7 and 20 months after the beginning of the experiment. The soil samples were wetted to a water content corresponding to ∼80% of the total water capacity and placed in hermetic vessels containing vials with a periodically renewed alkali solution. The incubation was performed at room temperature for 3.5 months; the alkali solutions in the vials were replaced and titrated 12 times during this period. Mineralization curves were plotted from the amounts of carbon dioxide absorbed by a 0.3 N NaOH solution, which were calculated for each time interval; its 14 C content was determined by the scintillation method. The experimental treatments also included the determination of the OM mineralization rate in material from the AE horizon pretreated with a heavy liquid or a heavy liquid and a 0.1 N NaOH solution. The differences between the mineralization rates of the labeled organic matter applied to the soil in the form of glucose, glycine, and uracil under the field conditions after the interaction for 7 and 20 months were revealed. The changes in the mineralization rate after the successive extraction of the labile organic matter with a heavy liquid and a 0.1 N NaOH solution were studied. It was shown that the transformation of the labeled low-molecular-weight organic compounds in the soil over 20 months included their strong inclusion into the humus composition, which was confirmed by the similar values of the mineralization constants of the native and 14 C-labeled OM. In addition, the treatments with the heavy liquid or the heavy liquid and the NaOH solution had almost identical effects on the mineralization of the native and 14 C-labeled OM. The mineralization constants of the native and 14 C-labeled OM in the samples taken after 7 months of the field experiment differed significantly.