Peat Organic Matter Research Articles

Water Table Fluctuation in Peatlands Facilitates Fungal Proliferation, Impedes Sphagnum Growth and Accelerates Decomposition

Northern peatlands are substantial carbon sinks because organic matter in peat is highly stable due to the low rate of decomposition. Waterlogged anaerobic conditions induce accumulation of Sphagnum-derived phenolic compounds that inhibit peat organic matter decomposition, a mechanism referred to as the “enzymic latch”. Recent studies have predicted that the water table in northern peatlands may become unstable. We observed that such unstable water table levels can impede the development of Sphagnum mosses. In this study, we determined the effects of low and high frequency water table fluctuation regimes on Sphagnum growth and peat organic matter decomposition, by conducting a year-long mesocosm experiment. In addition, we conducted a molecular analysis to examine changes in abundance of fungal community which may play a key role in the decomposition of organic matter in peatlands. We found that rapid water table fluctuation inhibited the growth of Sphagnum due to fungal infection but stimulated decomposition of organic matter that may dramatically destabilize peatland carbon storage. Increased pH, induced by the fluctuation, may contribute to the enhanced activity of hydrolases in peat. We demonstrated that the water table fluctuation in peatlands impeded Sphagnum growth and accelerates decomposition due to fungal proliferation. Thus, we suggested that understanding the microbial community in the northern peatlands is essential for elucidating the possible changes in carbon cycle of peatland under the changing world.

Особливості плантаційного лісорозведення на осушуваних торфовищах Лісостепу України та його вплив на ґрунт

Goal. To determine the most adapted wood breeds for plantation afforestation of different function in the conditions of drained peatlands of the Forest-Steppe. To study the peculiarities of growth and development of newly created forest crops in specific conditions of organogenic soils. To determine the influence of afforestation on the change of water-physical properties of drained organogenic soils. Methods. General scientific (hypotheses, inductions and deductions, analogies, generalizations) and special (field, laboratory, mathematical, statistical, computational) — for research and their generalization. Results. The best indicators of productivity in these conditions were shown by tree and bush willows, black poplar, sticky alder, and hybrids of Euro-American poplars. The optimal length of unrooted cuttings for the creation of energy plantations was 25 cm. For afforestation of black alder on drained organogenic soils, it is advisable to create forest crops with seedlings 1.0–1.2 m high according to the scheme 3.0×1.0 m, which ensures survival at the level of 98%. Over the last 52 years, the density of peat in the upper layer (0–30 cm) in the forest stand has not changed (the difference is 3%), while in the lower layers it has increased by 18–20%, but the soil density remains low (average 0.250 g/cm3) and high total moisture content (345%). The decrease in soil mineralization in forest stands compared to hayfields indicates a slowdown in the decomposition of peat organic matter under the forest, which is important for the preservation of peatlands. After the cycle of plantation afforestation, re-agricultural use of lands with improved water-physical properties of the soil is possible. Conclusions. The creation of forest plantations on drained organogenic soils is quite possible and expedient. With the use of different species composition and changes in planting density, you can create plantations of tree crops for different purposes. The highest indicators of productivity in these conditions had tree and bush willows, black poplar, alder sticky and hybrids of Euro-American poplars.

Soil amelioration using steel slag in drained peatland under oil palm plantation increases CO2 emission

Increasing the productivity of tropical peatland can be achieved by soil ameliorations using steel slag and lateritic soil. However, the effect of such ameliorants on the peat decomposition is not well understood. This study was aimed to evaluate the influence of soil ameliorants of steel slag and lateritic soil to peat decomposition as reflected by CO2 emission. A year study was conducted in smallholder oil palm plantation in Jambi Province, Indonesia to monitor CO2 emission from treatments plots of control (T1), steel slag 600 kg ha−1 (T2), lateritic soil 600 kg ha−1 (T3) and a combination of T2 and T3 (T4), which each treatment had 5 replications. CO2 emission was measured every three months by a closed chamber method. Results showed that CO2 emission were followed the order of T4>T2>T1≥T3. CO2 emission from T4 (49 ± 20 t ha−1 year−1) was 20% higher than T1 (40 ± 23 t ha−1 year−1), while T2 (44 ± 17 t ha−1 year−1) was 9% higher than T1. CO2 emission from T3 (40 ± 14 t ha−1 year−1) was similar to T1. This study showed that steel slag accelerates peat organic matter decomposition which is indicated by higher CO2 emission of steel slag treatments compare to other treatments.

Divergent effect of silicon on greenhouse gas production from reduced and oxidized peat organic matter

Peatlands store about 30% of the global soil carbon (C) stock. The decomposition of peat C in these systems depends on environmental parameters – such as water table levels and corresponding availability of electron acceptors for microbial respiration. Due to the latter, potential peat decomposition depends also on whether the material is initially oxidized or reduced prior to decomposition experiments.Recent studies revealed the importance of silicon (Si) for peat decomposition. High amounts of biogenic Si were found in peatlands, in particular in minerotrophic fens, and the importance of Si for graminoids and decomposability of respective litter has been widely discussed. Furthermore, the availability of Si was reported to influence the binding of phosphorus (P) to iron (Fe) and thereby the conditions under which decomposition proceeds. Yet the influence of Si on greenhouse gas production in peat under different initial redox conditions is largely unknown. Therefore, we intended to test the effect of Si on greenhouse gas production under different initial electron acceptor availabilities for microbial respiration, such as the availability of ferric Fe.We conducted two incubation experiments with initially oxidized and reduced peat organic matter (OM). We hypothesized that Si can mobilize P from Fe minerals, which increases microbial activity, and leads to higher production rates of carbon dioxide (CO2) and methane (CH4). Using the two different materials, we studied how initial redox conditions would modify effects of Si. As the predominant form of Fe as either ferric Fe-(oxy)hydroxides or as ferrous Fe minerals (sulfides, carbonates) is important for interaction with Si, we further hypothesized that Si effects should be stronger in initially oxidized peat in presence of ferric Fe, compared to initially reduced peat with ferrous Fe only.For incubation experiments using formerly oxidized material the Si addition increased P concentrations in the pore water, and more CO2 was produced. The onset of methanogenesis was much stronger with than without addition of Si, indicating a more rapid depletion of electron acceptors by faster rates of respiration. We explain this by more P being available stimulating microbial activity, and also by a direct effect of Si on microbial activity and methanogenesis. The incubation of formerly reduced OM did not show any effects of Si on respiration processes, presumably due to the absence of ferric Fe phases.In conclusion, there was a clear difference in the effect of Si addition on decomposition of formerly oxidized compared to long term reduced OM, with only oxidized peat OM or peat with ferric Fe phases present showing clear Si effects. Consequently, redox conditions and availability of ferric Fe are a main control for Si effects on OM decomposition and nutrient availability. Little effects of Si can be expected under permanently reducing conditions and in absence of ferric Fe phases.

Peat Storage Losses Investigation

The paper investigates the effect of self-heating, wetting and freezing of different milled peat types on field storage losses. It has been found that the loss of organic matter in peat due to self-heating depends on peat decay degree, type of product obtained, heating temperature (storage duration), preventive measures taken and the technological scheme of peat extraction. When such preventive measures as moving stacks, internal sealing and compaction of peat are taken, a decrease in self-heating and spontaneous combustion losses is observed. In two-stage harvesting, these losses are lower because of peat compaction in stacking operations. It has been established that there is a dependence of peat losses on its wetting and freezing, storage duration, and the total amount of precipitation accumulated over a certain period. With an increase in peat decay degree, the maximum wetting and freezing losses are several times lower than self-heating losses. These losses are 20% higher for upland peat than for lowland peat.

Economic Assessment of Low Humidity Peat Production Practice

The article presents a milled peat production practice based on deep bed drying up to a harvesting moisture content of 35%. The task of the developed technology is to minimize and stabilize the harvesting humidity in the field drying of peat, thereby reducing the time and thermal impact on the peat organic matter during a forced finish drying. The applied method of peat extraction provides for variable milling depth and differentiation of cycle harvesting to increase the number of cycles and the harvester seasonal output. An economic feasibility study has been carried out by the method of determining the operating costs per ton of a marketable product for each technological operation. It consists in a comparative assessment of two technological processes: the production practice based on intensification of milled peat drying up to a harvesting moisture content of 35% and the conventional harvesting of milled peat with moisture content of 45%. The developed technology of milled peat extraction makes it possible to ensure the required quality parameters in terms of humidity (≤ 35%) and to preserve natural bituminous components. Based on the economic assessment results, it has been found that there is a slight increase in operating costs per ton of a marketable product in comparison with the conventional practice.

Separation of Components in the Group Analysis of the Organic Matter of Peat: A Review

Methods and conditions for the separation of different groups of organic matter in the group analysis of peat, which have been developed and improved in different countries over more than 100 years, are analyzed. Data on the influence of the type of extractant, temperature, pH, extraction time, and other factors on the yield and properties of different groups of organic matter from peat are presented. It is shown that the separation of some organic matter components can significantly change the yield, molecular structure, and properties of other components. The degrees of changes in components with the use of different group analysis methods are different. To eliminate these disadvantages, it is necessary to search for instrumental techniques for the quantitative measurement of the concentrations of the main components in the organic matter of peat instead of extraction methods.

Influence of Drainage on Peat Organic Matter: Implications for Development, Stability, and Transformation.

The agricultural use of peatlands, the stabilization of the substrate for building or road construction or for increasing the capacity of soil to support heavy machinery for industrial activities (peat and petroleum extraction), harvesting to provide peat for energy, and the growing media and initiation of chemical processes must be preceded by drainage. As a consequence of drainage, peat underwent an irreversible conversion into moorsh (secondary transformation of the peat). The object of the study was to investigate comparatively the organic matter composition and molecular structure of humic acids (HAs) in the raised bog, fen, and peat-moorsh soils developed in various compositions of botanical cover, peat-forming species, and oxic and anoxic conditions as a result of the oscillation of ground water during drainage as well as to evaluate the vulnerability of soil organic matter (SOM) to decomposition. Drainage was shown to be the principal factor causing the various chemical compositions and physicochemical properties of HAs. Large and significant differences in chemical composition of peat and the properties of HAs were found to be related to the degree of decomposition. The HAs from drained peatlands were less chemically mature. In contrast, the HAs from fen and raised bog were found to be more mature than that of the corresponding drained peatlands. The above findings showed the distinguishable structure of HAs within the soil profile created by the plant residue biodegradation and formed in both oxic and anoxic conditions. The analytical methods of thermal analysis together with the optical densities and paramagnetic behaviour are suitable and effective tools for studying structure–property relationships characterizing the origin and formation process of HAs in various environmental conditions.

Agrogenic evolution of organic matter in peat soils of Western Siberia

The influence of the groundwater level (GW), vegetable crop rotation and mineral fertilizers on the change in the composition of organic matter of medium-thick peat soil was determined. The study was conducted on lysimeters with an adjustable level (0.5; 1.0; 1.5 and 1–2.0 m) of groundwater occurrence; in a vegetable-feed crop rotation spread in time and space; under perennial grasses without prior cultivation of annual crops. It was established that in the arable layer (0.2 m) of peat soil, the bitumen content at GW level of 0.5 m was lower by 1.65% than at a depth of 1.0 m, and by 4.34% than at a depth of 1.5 m. The maximum amount of water-soluble substances (5.68%) and substances hydrolyzable by 2% HCl (34.25%) was established at GW level of 0.5 m. It was 1.2 and 3.4–3.8% higher than at groundwater level of 1–1.5 m, respectively. With GW level of 1.5 m, the amount of humic acids decreased by 4.5% compared to their occurrence at a depth of 0.5 m. The amount of fulvic acids in the arable layer depends on the GW level (r = 0.79). The content of substances hardly hydrolyzable by 80% H2SO4 in the arable layer decreased from 2.82 to 2.31% with an increase in groundwater depth from 0.5 to 1.5 m. It was observed that the amount of lignin decreased with an increase in groundwater depth from 0.5 (6.66%) to 1.5 m (5.30%). Five- year cultivation of crops in the vegetable-feed crop rotation did not lead to significant changes in the composition of the organic matter of peat. Grassing of peat soils with perennial grasses without sowing pre-crops ensures preservation of peat organic matter and prevents its substantial transformation. Mineral fertilizers reduce the rate of accumulation of hardly-hydrolyzable and non-hydrolyzable forms due to more severe oxidative-hydrolytic conditions in the soil and because of an increase in the amount of fresh plant material as a result of crop and root residues.

Environmental monitoring of low-level radioactive waste disposal in electrochemical plant facilities in Zelenogorsk, Russia

The concentrations of radionuclides, especially anions, in water can substantially exceed local background levels in the vicinity of former and currently operating uranium enrichment plants. In this study, we present new data on environmental monitoring near the uranium sludge collector of an electrochemical plant (ECP) in Krasnoyarsk Krai, Russia. We first tracked the complex biogeochemical processes that can affect the fate and transport of U in highly nitrate-polluted ground- and surface water. We described the main mechanisms of U immobilization: (a) biogenic and abiogenic reduction (microbial nitrate reduction caused dramatically Eh decrease), (b) sorption by organic matter in peat and by microbial biofilms on a sandy rock surface, and (c) precipitation with biogenic and abiogenic phases. The intensity of the biogenic and abiogenic factors depended on the dynamics of changes in the oxidation-reduction potential (ORP)-pH conditions as well as organic- and inorganic anion concentrations with distance from the source of pollution. Anammox bacteria were found in areas with high nitrate pollution, and we believe that they played a key role in lithotrophic nitrogen consumption and primary organic production. These data can form the basis for complex groundwater remediations close to U sludge repositories and can be implemented beyond the ECP site itself.

GreenhousePeat: a model linking CO<sub>2</sub> emissions from subsiding peatlands to changing groundwater levels

Abstract. Oxidation of organic matter in peat above the phreatic groundwater table causes subsidence and carbon dioxide (CO2) emissions. Because 25 % of the Netherlands has shallow peat layers in its subsurface, it is essential for Dutch policy makers and stakeholders to have reliable information on present day and near future CO2 emissions under changes in groundwater levels. Furthermore, it is important to reduce greenhouse gas emissions in view of international agreements. We are developing GreenhousePeat: a nationwide model that synthesizes information on peat organic carbon content, land subsidence, and CO2 emission monitoring to model present-day and future CO2 emissions from subsiding peatlands. Here, we discuss the approach and input data of GreenhousePeat. GreenhousePeat is based on a UNFCCC approved model to predict CO2 emissions, albeit based on new input data: 3-D organic matter maps, nationwide subsidence rates, and ranges in oxidation fraction. We validate model outcomes with previously documented CO2 emissions measured at four different locations. We found that for one site the upper bound of the model reproduces the measured CO2 emissions. The modelled emissions at two sites have a relative deviation of approximately 73 % to 29 % from the measured emissions. Whereas one site is a net CO2 sink, although low emissions were modelled. Finally, we conclude on the suitability of the model for CO2 emission forecasting and suggest improvements by incorporating groundwater level information and land use type.

Surface and subsurface material selections influence the early outcomes of boreal upland forest restoration

Soil is an essential component supporting the growth and maintenance of forests, providing anchorage, water, and nutrients for a diversity of plants. In Canada's boreal forest, surface soils differ widely in their chemical and physical conditions, ranging from coarse to fine textured mineral soils in the uplands to organic soils in the lowlands. Industrial disturbances in the boreal region require the selective salvage of surface and sub-soils from low- and upland areas during open pit mine operations, which can be used to reconstruct different soil profiles by arranging the materials in variable layers and thicknesses. The type of materials and their configuration in the reconstructed soil profile can have a profound effect on early forest establishment in reclaimed areas. We compared the growth of trembling aspen (Populus tremuloides Michx.), jack pine (Pinus banksiana Lamb.), and white spruce (Picea glauca Moench.) on sites that had different reconstructed soils caps using varying surface soil materials (salvaged lowland peat and upland forest floor material (FFM)), placement depths (10 or 30 cm for peat, 10 or 20 cm for FFM), and subsoil material types determined by salvage depth (Bm, BC, and C). Early seedling establishment and growth and soil and climatic parameters were monitored over a five-year period. Generally, seedling growth was greatest on FFM and appeared to be related to phosphorous availability, while peat as a surface soil reduced growth, likely due to delayed soil warming in the spring and cooler soil conditions that potentially limited resource availability. However, the greater water holding capacity of the organic matter in peat also provided a benefit for seedling growth that was apparent during water limiting climatic conditions. The underlying subsoil material also influenced growth, particularly later in establishment when roots occupied the deeper subsoils. Aspen growth was greatest when the subsoil was shallow salvaged and represented a weathered subsoil (Bm) compared to the more deeply salvaged, less weathered subsoils BC and C. Aspen and pine seedlings, with their larger roots systems, may have benefited from small increases in the silt fraction of the subsoils, likely due to the greater water holding capacity of these otherwise coarse textured sandy soils. Spruce regeneration responded marginally to soil treatments because of its overall slow growth-strategy and tolerance to resource limitations. Our results indicate that different soil capping strategies affect the performance of forest regeneration during post-mining site reconstruction, and boreal forest species may vary in responses according to their ecological life strategies.

Characterisation of humic acids in fen peat

Fens store significant amounts of organic matter and thus are of high importance from the perspective of the organic carbon biogeochemical cycle. Fen peat comprises moderately to highly decomposed higher plant remains with relatively high mineral matter content. Humic acids form the major part of fen peat organic matter; they are also the most refractory and recalcitrant natural substances to degradation, and thus they contain essential information regarding mire and peat development over large periods of time as well as the organic carbon biogeochemical cycle. Moreover, humic substances in fen peat are a prospective resource for applications in agriculture and other sectors. The aim of this study was to comparatively study properties of humic acids isolated from fen peat of varied botanical compositions and origins and to compare the impact of the precursor biological material on properties of the humification process and the resulting humic acids. The formation of humic acids of varied origins shows similarities; however, at the same time, differences can be found in the further development of humic acids, depending on the environment in which they are present.

CO2 fluxes from drained tropical peatland used for oil palm plantation in relation to peat characteristics and crop age after planting

Large expansion of oil palm plantation on peatland has changed its important role for carbon sink into a carbon source. Conversion of peat swamp forest with high carbon density into a monoculture of oil palm has released the significant amount of carbon into atmosphere either carbon previously stored in forest biomass or carbon stored in peat organic matter. Drainage canal to artificially lower groundwater level as a prerequisite of oil palm cultivation provides the favorable condition for soil microbes activities in decomposing peat organic matter resulted in CO2 flux increase. The fluctuation of groundwater level and variation of environmental factors near the peat surface may regulate the rate of CO2 released from the soil. We aimed to measure CO2 fluxes from two sites of oil palm plantation with different peat characteristics and analyzed the correlation with groundwater level, soil temperature, air temperature, gravimetric water content, peat pH, oxidative reductive potential, and crop age. The measurement has been conducted from September 2016 to April 2017 in West Kalimantan, Indonesia by using portable infrared gas analyzer EGM 4. In addition to soil sampling at the same time as the gas measurement, we collected soil samples for some peat characteristics analysis consist of bulk density, particle density, porosity, soil organic matter, ash content, carbon, and nitrogen content prior to CO2 flux measurement. Our result shows that the difference of peat chemical characteristics between two sites has resulted in different CO2 flux. Oil palm ages seemed to affect CO2 flux by regulating microclimatic condition around crop canopy. Another finding is the insignificant relationship between CO2 fluxes and groundwater level unless the groundwater level reached more than 50 cm from the peat surface. It implies that maintaining groundwater level-up to 50 cm resulting in similar CO2 flux.

Organic matter composition and paleoclimatic changes in tropical mountain peatlands currently under grasslands and forest clusters

Tropical peatlands are important ecosystems for Planet Earth, as they store large amounts of carbon and water. A better understanding of the impact of vegetation type and altitude in content, composition, and rate of accumulation of organic matter is key for assessing the current role of such environments. This study evaluated fibric and soluble fractions as well as the lignocellulosic and the isotopic compositions of the peat organic matter from four tropical mountain peatlands located at different altitudes of the Serra do Espinhaço Meridional, state of Minas Gerais, Brazil. The peatlands are currently under grasslands and forest clusters. Samples of peat under both vegetation types were collected and analyzed for organic matter fractions, cellulose, and lignin (van Soest method), as well as carbon and nitrogen isotopes. Different depths were chosen for radiocarbon dating of selected samples. The organic matter of peatlands currently under grasslands and forest clusters presented differences in soluble fractions, lignocellulosic composition, and δ13C values. Multivariate analyses allowed grouping the peatlands by altitude and vegetation type. The chronological succession of grassland and forest clusters in tropical mountain peatlands was influenced by altitude and was related to paleoclimatic changes.

Antimonite Complexation with Thiol and Carboxyl/Phenol Groups of Peat Organic Matter.

Peatlands and other wetlands with abundant natural organic matter (NOM) are important sinks for antimony (Sb). While formation of Sb(III) sulfide phases or Sb(III) binding to NOM are discussed to decrease Sb mobility, the exact binding mechanisms remain elusive. Here, we reacted increasing sulfide concentrations with purified model peat at pH 6, forming reduced organic sulfur species, and subsequently equilibrated the reaction products with 50 μM of antimonite under anoxic conditions. Sulfur solid-phase speciation and the local binding environment of Sb were analyzed using X-ray absorption spectroscopy. We found that 85% of antimonite was sorbed by untreated peat. Sulfide-reacted peat increased sorption to 98%. Shell-by-shell fitting of Sb K-edge X-ray absorption fine structure spectra revealed Sb in untreated peat bound to carboxyl or phenol groups with average Sb-carbon distances of ∼2.90 Å. With increasing content of reduced organic sulfur, Sb was progressively coordinated to S atoms at distances of ∼2.45 Å and Sb-carbon distances of ∼3.33 Å, suggesting increasing Sb-thiol binding. Iterative target factor analysis allowed exclusion of reduced inorganic Sb-sulfur phases with similar Sb-sulfur distances. In conclusion, even when free sulfide concentrations are too low for formation of Sb-sulfur precipitates, peat NOM can sequester Sb in anoxic, sulfur-enriched environments.

NITROGEN REGIME OF PEAT SOIL IN NORTHERN PART OF TRANS-URALS ZONE

The paper highlights the results of many-year (1982-1992, 2011-2014 гг.) research on the concentration of mineral nitrogen in the arable medium peat soil layer of the forest-steppe of Trans Urals zone. The research was carried out on the experimental-reclamation system Reshetnikovo located in the central part of the Tarman bog on the second lacustrine-alluvial basin of the Tura River in Tyumen region. The soils on the experimental plot have a slightly acidic reaction (5.2 - 5.9), relatively low hydrolytic acidity (28.1 - 40.8 mg-eqv/100 g of soil), relatively low degree of base saturation (61.7 - 75.5%), high gross nitrogen concentration (3.1 - 3.9%), low concentration of phosphorus (0.09 - 0.14%) and potassium (0.02 - 0.05%). The researchers found out that mineralization of peat is slow and almost always fails to provide sufficient and continuous supply of nitrogen, despite its large gross reserves. Due to insufficient number of mobile nitrogen compounds from peat organic matter during the growing season it is necessary to apply nitrogen fertilizers. When peat soils contain low concentrations of phosphorus (0.7 - 3.7 mg/100 g of soil), the highest number of nitrate nitrogen is accumulated in the arable layer under perennial grasses due to its low consumption for the yield. Re-reclaimed peat soil is characterized by negative nitrogen concentration. As perennial grasses require nitrogen, it is fulfilled by means of fertilizers on 41.4 - 72%. The authors observed a tendency of reducing nitrate reserves under perennial grasses even if nitrogen fertilizers are applied. This indicates a decrease in the mineralization rate of peat organic matter. The ammonium nitrogen concentration increases. Discontinuance of nitrogen fertilizers use reduces the nitrate nitrogen concentration on 30-49% in the first year and on 46.7-59.1% by the end of the fourth year of after-effect. The amount of ammonium nitrogen increases in 1.6-3.7 times in 4 years.

CHARACTERISTICS OF HORNY ALTAI PEATS AND THEIR BIOLOGICAL ACTIVITY IN PLANT TISSUE CULTURE

The search for new raw materials of biologically active substances of natural origin is an urgent task for the modern period. Peat in this respect is a relatively cheap and almost unlimited raw material base. Peat of swamps can be used widely in agriculture for receipt of biologically active substances are of great interest in the territory of the Gorny Altai. The purpose of this work is to study the composition of organic matter of peats of the Gorny Altai, to choose peat raw materials for biologically active production and to study their biological activity. The object of the study was 46 swamps of the Gorny Altai. The following analyses were carried out in peats: botanical composition, degree of decomposition, ash content, group composition of peat organic matter. The composition of humic acids (ha) was analyzed by IR spectroscopy. For determine of the biological activity of humic acids was used plant tissue cultured . The results of the research allowed to distinguish peats by the content of HA: buckbean peat (47.0% of HA), wood peat (50.0% of HA), fern peat (55.0% of HA), grass peat (30.0–45.0% of HA), sedge peat (5.6–58.0% of HA), grass-buckbean peat (43.0–56.5% of HA) and to outline the raw material base for the production of BAS – peatland Turochak. According to the optimal characteristics of HAs, a sample was taken from a depth of 325-375 cm, HA was isolated. The biological activity In humic acid was determined with the use of plant tissue culture. High biological activity are proven of the preparations of HA from the peatland Turochak, which resulted in the acceleration of microclonal propagation of plants in vitro.

Diagenesis of Organic Matter in Peat: Rock–Eval Pyrolysis Data

Rock–Eval pyrolysis data were obtained on a collection of peat samples at various diagenesis stages (from depths of 0–350 cm) from the Gurskoe deposit, lower Amur area, and on producers of organic matter (OM). The pyrograms of the peat OM are superpositions of three peaks: (1) a low-temperature one, with temperatures of hydrocarbon release lower than 300°C, (2) an intermediate-temperature peak, with hydrocarbons released at 300–400°C, and (3) a high-temperature one, corresponding to hydrocarbon release at temperatures above 400°C. The peaks correspond to the lipid, labile, and kerogen OM components, respectively. The diagenetic transformation of OM is associated with a gradual decrease in the contents of the lipid and labile components and an increase in the content of the kerogen component. The process is the most intense in the upper part of the vertical section.

Online supercritical fluid extraction mass spectrometry (SFE-LC-FTMS) for sensitive characterization of soil organic matter.

We report a novel technical approach for subcritical fluid extraction (SFE) for organic matter characterization in complex matrices such as soil. The custom platform combines on-line SFE with micro-solid phase extraction, nano liquid chromatography (LC), electrospray ionization and Fourier transform mass spectrometry (SFE-LC-FTMS). We demonstrated the utility of SFE-LC-FTMS, including results from both Orbitrap and FTICR MS, for analysis of complex mixtures of organic compounds in a solid matrix by characterizing soil organic matter in peat, a high-carbon soil. For example, in a single experiment, >6000 molecular formulas can be assigned based upon FTICR MS data from 1-50 μL of soil samples (roughly 1-50 mg of soil, dependent on soil density), nearly twice that typically obtained from direct infusion liquid solvent extraction (LSE) from an order of magnitude larger volume of the same soil. The detected species consisted predominately of lipid-like, lignin-like and protein-like compounds, based on their O/C and H/C ratios, with predominantly CHO and CHONP molecular compositions. These results clearly demonstrate that SFE has the potential to effectively extract a variety of molecular species and could become an important member of a suite of extraction methods for studying SOM and other natural organic matter. This is especially true when comprehensive coverage, minimal sample volumes, and high sensitivity are required, or when the presence of organic solvent residue in residual soil is problematic. The SFE based extraction protocol could potentially enable spatially resolved characterization of organic matter in soil with a resolution of ∼1 mm3 to facilitate studies probing the spatial heterogeneity of soil.