Relationships between the Size of Aggregates,Particulate Organic Matter Content,and Decomposition of Plant Residues in Soil

Eurasian Soil Science - The distribution of total organic matter (Corg), particulate organic matter (CPOM), and potentially mineralizable organic matter (C0) in mega- (10–5 and 5–2 mm),...     

Biochemistry of lignin in soils of periodic excessive moistening (from the Example of Agrogray Soils in Opolie Landscapes of the Russian Plain)

Tissues of Angiospermae (deciduous arborous and herbaceous plants) were found to take part in the formation of humus in the agrogray soils. The proportions of lignic phenol contents between the soils did not change neither upon their plowing, no their drainage. Within the catenas studied, the maximal accumulation of phenol compounds takes place in the soils of the mesodepressions with long-term reduction conditions and in the soils of the microdepressions with spring perched water on two levels. In the Fe-Mn nodules of the agrogray soils, lignin of higher plants was found. Its fractional composition was correlated with the predominant vegetation. With the increasing size of the nodules, the amount of products of lignin oxidation in the nodules decreased due to its mineralization. Drainage caused a deep transformation of lignin in the Fe-Mn nodules, especially in the coarse fractions of concretions. The mineralization of lignin aromatic compounds under aerobic conditions was accompanied by the significant increase in the share of phenol acids.     

Estimation of the Biogenicity and Bioactivity of Gleyed Agrogray Nondrained and Drained Soils

Eurasian Soil Science - A comparison of the biological activity and biogenicity of drained and nondrained gleyed agrogray soils (Luvic Greyzemic Stagnic Phaeozems) of Moscow oblast has been carried...     

Transformation of lignin in surface and buried soils of mountainous landscapes

The content and composition of the lignin phenols in plants and soils of vertical natural zones were studied in the Northern Caucasus region and Northwestern Tien Shan. Three types of lignin transformation were revealed: steppe, forest, and meadow ones. It was shown that the degree of oxidation of the biopolymer during the transformation of organic matter increased when going from the living plant tissues to humic acids in surface and buried soils. The portion of lignin fragments remained unchanged during the biopolymer transformation in the following series: plant tissues-falloff-litter-soil-humic acids-buried humic acids. It was also shown that the biochemical composition of the plants had a decisive effect on the structure of the humic acids in the soils. The quantitative analysis of the lignin phenols and the ¹³C NMR spectroscopy proved that the lignin in higher plants was involved in the formation of specific compounds of soil humus, including aliphatic and aromatic molecular fragments. The first analysis of the lignin content and composition in buried soils of different ages was performed, and an increase in the degree of oxidation of the lignin structures was revealed in the soil chronoseries. It was proposed to use the proportions of lignin phenols in surface and buried soils as diagnostic criteria of the vegetation types in different epochs.     

Ecological evaluation of oil-contaminated soils (Sakhalin) using enchytraeidae

The ecological status of oil-contaminated soils of Sakhalin and their background analogues has been evaluated with the use of soil invertebrates. The survival rates of Enchytraeus albidus in soils with different textures and the contents of organic carbon and nutrients have been compared. The indicative role of soil mesofauna (Enchytraeus albidus) for the ecological evaluation of oil-contaminated soils with due account for their properties has been shown. The permissible residual concentration of oil hydrocarbons in some soils of Sakhalin—acid brown forest soils (Umbrisols), high-moor peat soils (Histosols), acid meadow alluvial soils (Fluvisols), cultivated meadow soddy soils (Anthrosols), and mucky-podzolic surface-gleyed soils (Gleysols)— has been determined from data on the response of Enchytraeus albidus to different levels of the soil contamination with oil hydrocarbons.     

The structure of bacterial communities in natural and anthropogenic brown forest soils of the Botanical Garden on Murav’eva-Amurskogo Peninsula

The microbiological characterization of the brown forest soils in the territory of the Botanical Garden-Institute of the Far East Division of the Russian Academy of Sciences in southern Primor’e is given. The high humus content and weakly acid reaction of these soils were shown to provide the optimal conditions for the development of bacteria. In the brown forest soils differing in the thickness of the humus horizons, all the ecologic-trophic groups of bacteria were present and the bacterial communities were highly diverse. The structure of the bacterial communities was identical in all the organomineral horizons of the soils and varied greatly by the seasons. In the anthropogenically disturbed soils, the share of corynebacteria, which are resistant to stress and capable of the destruction of xenobiotics, decreased.     

Humus of soils of the Altai Mountains

Data on the humus composition and specific features of soils in the Altai Mountains obtained in the long-term studies initiated by R.V. Kovalev are discussed. The average statistical values for the content of the main humus components and their ratios in different soil types were obtained by processing the data on 307 soil pits. The comparison of the soils belonging to the same type and occurring in the northwestern, central, and southeastern regions of the Altai Mountains in terms of the C ha/C fa ratio (one of the integral indices of the humus composition) showed that there were no significant differences between them. The overlapping intervals of the average values of this ratio testified to this fact. For instance, the average C ha/C fa ratios in the mountain tundra soils of the regions mentioned amounted to 0.70 ± 0.03; 0.72 ± 0.02; and 0.69 ± 0.03, respectively, and, in the mountain meadow soils, they amounted to 0.67 ± 0.03; 0.69 ± 0.04; and 0.67 ± 0.03, respectively. The mountain brown forest soils that are components of the soil cover only in the northwestern and central regions also differ insignificantly by this parameter (0.88 ± 0.05 and 0.89 ± 0.03, respectively). In the soils of the Altai Mountains, the dependence between the portion of humic acids and the mean annual air temperature (HA (%) = 29.54 + 1.06T(°C), r = 0.71) and the ratio of the portion of fulvic acids to the mean annual precipitation (FA (%) = 9.70 + 0.029W, r = 0.74) was shown to be similar to those in all the soils of mountainous southern Siberia. These facts enabled us to apply regression equations for a quantitative reconstruction of the paleoclimate components according to the humus composition. Original Russian Text ￠ M.I. Dergacheva, E.I. Kovaleva, N.N. Ryabova, 2007, published in Pochvovedenie, 2007, No. 12, pp. 1416–1421.     

Drill cuttings in the environment: possible ways to improve their properties

Journal of Soils and Sediments - The disposal of drill cuttings (DCs) in landfills is one of the major impacts of oil extraction on the environment. The DC composition is predetermined by the type...