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The specific features in the distribution of organic and mineral nitrogen compounds in marsh and tundra soils of the European Russian Arctic (coastal areas of the Barents and White Seas) were analyzed. Total nitrogen was determined by gas chromatography (CHNS-O elemental analyzer), and inorganic nitrogen, by photometry. The composition of hydrolyzable amino acids was analyzed by liquid chromatography on ion exchange resins. Mineral compounds accounted for an insignificant part of the total soil nitrogen; its major part (to 97% of the total content) was represented by organic substances (Nоrg). The Nоrg varied within a wide range in both marsh (0.3–15.8 g/kg) and tundra soils (5–20 g/kg in the peat horizons and 0.3–2 g/kg in the mineral horizons). The content of N- varied from 5 to 20 mg/kg in marsh soils and from 30 to 200 mg/kg in tundra soils. In marsh soils, the content of nitrate nitrogen was 0.2–4.6 mg/kg in the upper horizons. Marsh soils were characterized by the accumulation of Nоrg either on the surface or in the middle part of the profile in the presence of humus-accumulative horizons buried under recent marine sediments. The accumulation of Nоrg and N- was observed above the permafrost in the peat-gley soil and in the permafrost in the oligotrophic peat soil. The content of hydrolyzable amino acids in the soils of different geneses was 0.6–8 g/kg, which corresponded to 30–60% of the soil organic nitrogen and 2–12% of the soil organic carbon. Distribution patterns of the amino acid nitrogen and organic nitrogen in the soil profiles were similar. The qualitative composition of amino compounds was relatively uniform, and the ratios of most of them were close. The shares of arginine, histidine, phenylalanine, tyrosine, and isoleucine were less than 4% each; of lysine, valine, proline, serine, and threonine, 5 to 7%; and of alanine and leucine, 10–12%. The share of glycine increased downward the profile from 12 to 20%, and the shares of aspartic and glutamic acids decreased from 11 to 6%. In marsh soils, Nоrg, N- , and nitrogen of most amino acids correlated (r = 0.6–0.9) with the clay content and nonsilicate iron forms. The tightest correlations were observed between the dithionite-soluble iron and the nitrogen of threonine and histidine. [ABSTRACT FROM AUTHOR]

Water extracts from soils of the Barents Sea coast (the Khaipudyr Bay) were analyzed for the contents of organic carbon and total nitrogen by the method of high-temperature catalytic oxidation with non-dispersive IR registration; the contents of low-molecular-weight acids, carbohydrates, and alcohols were determined by gas chromatography and gas chromatography–mass-spectrometry. The mass fraction of inorganic carbon was measured potentiometrically, and the content of inorganic nitrogen (N– N– ) was determined by photometry. In marsh soils (Tidalic Fluvisols (Arenic or Loamic, Epiprotosalic)), = 0.1–0.8, = 0.01–0.05 g/kg, = + 0.01, and = 7–21. The content of individual components does not exceed 20 mg/kg, including carbohydrates (50–90%), acids (10–50%), and alcohols (<3%). In peat horizons of tundra soils (Cryic Histosols and Histic Cryosols), = 4–10, ~ 0.2 g/kg, and = 25–56. Litter and peat horizons accumulate both individual humus components and total dissolved organic carbon. The total weight of the identified substances is 200–300 mg/kg, 80–90% of them are carbohydrates, 10–20% are acids, and 0–9% are alcohols. The accumulation of and (N– takes place above the permafrost table. It is argued that the ratios of organic forms of carbon and nitrogen in soil water extracts and the content of low-molecular weight organic compounds in soils can be used as indicators of pedogenic processes in the Far North. [ABSTRACT FROM AUTHOR]