Characterization of Humic Acids in Mountainous Meadow Soils and Burozems of the Crimea Using 13C-NMR

Kostenko, I. V.; Abakumov, Evgeny

doi:10.1134/s1064229318120062

Cited by 11 publications

(7 citation statements)

References 10 publications

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“…In the studied samples, a relatively high content of aromatic fragments accumulates, and their content is maximally comparable to the forest-steppe zone [42] (46-47% AR), in which an active process of transformation of plant residues and the formation of HAs is underway. A similar content is noted in the mountainous regions of the Crimea [48] with mountain meadow vegetation (43-46% AR). In more northern regions, the content of aromatic structures is significantly lower [27,39,41] than in the studied samples (30-38% AR), this is due to a change in the composition of plants for boreal species (mosses, lichens), which are enriched in lipids (cutins, fatty acids) [29].…”

Section: Stabilization Of Organic Matter In the Soils Of Chernevaya Taigasupporting

confidence: 73%

Elemental and Molecular Composition of Humic Acids Isolated from Soils of Tallgrass Temperate Rainforests (Chernevaya taiga) by 1H-13C HECTCOR NMR Spectroscopy

et al. 2021

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The soils of Chernevaya taiga (tallgrass fir-aspen hemiboreal rainforest) have high fertility in comparison with oligotrophic analogs formed in boreal taiga. We have studied humic acids isolated from the soils of Chernevaya and oligotrophic taiga in the Novosibirsk, Tomsk, Kemerovo and the Altai regions of Russia and for the first time the structural and molecular composition of humic acids was determined using 13C CP/MAS and 1H-13C HETCOR NMR spectroscopy. According to data obtained in this study, up to 48% of aromatic compounds accumulate in the soils of Chernevaya taiga, which is higher than in the oligotrophic taiga and comparable with this rate of steppe Chernozems. In the course of active processes of transformation of organic matter, a significant number of aromatic fragments accumulates in the middle horizons of soil profiles. Using 13C CP/MAS spectroscopy, it was possible to identify the main structural fragments (aliphatic and aromatic) that formed in humic acids of the Chernevaya taiga. The HETCOR experiment made it possible to accurately determine the boundaries of chemical shifts of the main groups of structural fragments of humic acids. Our results demonstrate that the stabilization of organic compounds occurs in the soil of the Chernevaya taiga, which leads to the resistance of organic matter to biodegradation that is not typical for benchmark soils of boreal environments.

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Section: Stabilization Of Organic Matter In the Soils Of Chernevaya Taigasupporting

confidence: 73%

Elemental and Molecular Composition of Humic Acids Isolated from Soils of Tallgrass Temperate Rainforests (Chernevaya taiga) by 1H-13C HECTCOR NMR Spectroscopy

et al. 2021

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“…Starting from the soils of the tundra zone to chernozems, the PBA varies from 40-50 days to 160-170 days. In the dark chestnut soils of Dagestan, these indicators are 190-194 days and, depending on this, the Cg:Cfc ratio is 2.2-2.4 [10][11][12][13].…”

Section: Resultsmentioning

confidence: 99%

“…Humus is a source of energy in the soil, since it absorbs the passing solar energy, as well as the energy released from the soil, as a result of biochemical and redox processes [10]. At the same time, humus is a vital source of plant nutrition and biological value of many nutrients, especially nitrogen and carbon dioxide [10,11]. As a result of humus mineralization, which is a product of dying off, decomposition and humification of organic residues, containing calcium, magnesium, potassium, ammonia in the soil are converted into a new form -into compounds that are more accessible.…”

Section: Introductionmentioning

confidence: 99%

Conditions and factors of humus formation in soils of mountain and foothill

Tashkuziev¹,

Shadieva

2021

E3S Web Conf.

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On the basis of information on the climatic factor, the intensity of humus formation in the soil was estimated. It was revealed that as the transition from the plain to the foothills and low mountains due to changes in atmospheric precipitation and hydrothermal regime, the period of biological activity (PBA) of the soil increases from the plain to the mountains. The balance of annual radiation in the foothill plain is 47 kcal/cm2, in the high-mountain belt - 53 kcal/cm2. As the transition from the plain to the mountainous part of the relief, an increase in soil PBA was revealed and, in accordance with this, the content and reserves of humus, as well as labile humic substances in the humus composition, increase. By the type of humus, light gray soils are humate-fulvate and fulvate; typical, dark gray soils and mountain brown soils, fulvate-humate; light brown meadow-steppe soils, and humate. It also provides information on the energy reserves of humus for the considered soils. The correlations between the indicators of PBA and humus for horizon “A” in the studied soils were calculated.

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“…HAs were precipitated with 1 M HCl. To purify the HAs preparations, they were subjected to dialysis [32,41,42].…”

Section: Laboratory Methodsmentioning

confidence: 99%

Humic Acids Formation during Compositing of Plant Remnants in Presence of Calcium Carbonate and Biochar

Орлова

Abakumov

et al. 2022

Agronomy

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The investigation of the mechanisms organic matter transformation in compost organic fertilizers is an urgent task of modern soil ecology and soil chemistry. The main components of such fertilizers are newly formed, weakly humified labile humic acids (HAs). The objective of the study is to determine the mechanism of converting the newly formed HAs into the forms with increased resistance to microbiological and biochemical influences. Obtained during the plant residues decomposition, HAs were studied in the incubation experiment (0, 30, 90 days). Calcium carbonate and biochar produced by rapid pyrolysis from birch and aspen wood, at 550 ℃, were used as the composting mixture compounds. Decomposed plant residues—fresh aboveground mass of clover (Trifolium pratense L.), rye (Secale cereale L.), as well as dry oat straw (Avena sativa L.L.) were the material used for humification. To obtain Has, 0.1M NaOH and 0.1M Na4P2O7 were used. Then, HAs were separated from fulvic acids (FAs) using a 0.5 M H2SO4. The amount of labile HAs (HAs1) was estimated by their content in 0.1 M NaOH. The amount of stabilized HAs (HAs2) was calculated by the difference between the HAs content in 0.1 M Na4P2O7 and 0.1 M NaOH. Preparation of HAs for elemental composition and NMR analysis was performed according to the International Humic Substances Society’s recommendations. The possibility of converting newly formed HAs into stable forms (calcium humates), whose share in the HAs composition reaches 40–50%, has been shown. However, the mechanism of HAs transformation under the studied reagent’s influence was different. In the presence of calcium carbonate, it is caused by the physicochemical processes of newly formed HAs rearrangement. However, in the presence of biochar, this is due to the humification processes’ intensification and to the increase in the aromatization degree confirmed by the increase in the optical density, as well as by the increase in carbon and oxygen proportion, and by the decrease in hydrogen proportion in HAs molecules. The understanding of HAs formation and transformation mechanisms at the early humification stages can help to optimize the methods of obtaining organic fertilizers.

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Characterization of Humic Acids in Mountainous Meadow Soils and Burozems of the Crimea Using 13C-NMR

Cited by 11 publications

References 10 publications

Elemental and Molecular Composition of Humic Acids Isolated from Soils of Tallgrass Temperate Rainforests (Chernevaya taiga) by 1H-13C HECTCOR NMR Spectroscopy

Elemental and Molecular Composition of Humic Acids Isolated from Soils of Tallgrass Temperate Rainforests (Chernevaya taiga) by 1H-13C HECTCOR NMR Spectroscopy

Conditions and factors of humus formation in soils of mountain and foothill

Humic Acids Formation during Compositing of Plant Remnants in Presence of Calcium Carbonate and Biochar

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