Soil Organic Matter Dynamics Research Articles

Stable and Mobile (Water-Extractable) Forms of Organic Matter in High-Latitude Volcanic Soils Under Various Land Use Scenarios in Southeastern Iceland

High-latitude regions store substantial amounts of soil organic matter (SOM). Icelandic volcanic soils have exceptional capabilities for SOM accumulation, but recent changes in land use can significantly impact it. Water-extractable organic matter (WEOM) represents a labile SOM pool and serves as a reliable index of SOM dynamics. We assessed the stable carbon (C), stable nitrogen (N), and WEOC (water-extractable organic carbon), as well as WETN (water-extractable total nitrogen), concentrations in soils under different land uses—semi-natural habitats (tundra and wetland) and human-managed areas (intensively and extensively grazed pasturelands and formerly and presently fertilized meadows)—in southeastern Iceland. The results suggest that human-managed sites contain more total C and N but less WEOM per unit of total C or N than semi-natural habitats, except for wetlands. Wetlands exhibited the highest WEOM content. Extensive pasturelands and fertilized meadows are becoming more common in local ecosystems, highlighting the direction of changes in Icelandic grasslands management.

Agro-ECosystem Studies Based on Lotka-Volterra Modelling and Fourth Order Longe-Kuta Approach

In this paper, an agroecosystem food web model based on the Lotka-Volterra equation was constructed to simulate the ecosystem transition from forest to farmland in the state of Mato Grosso, Brazil, covering the producers, consumers at all levels, and soil organic matter dynamics equations. The model was solved using the fourth-order Ronger-Kuta method (RK4), optimised and evaluated by defining an objective function containing economic benefits and ecological sustainability and related assessment indicators, and determining the weights of the indicators using AHP and EWM analysis. On this basis, two new species, leaf-cutting ants and red-eyed wasps, were introduced to adjust the dynamic equations of the model and solved again. The results showed that the introduction of the new species enriched the ecosystem structure, improved the soybean yield and enhanced the ecosystem stability, and the objective function values of the new model were better than the original model, which provided valuable references for ecosystem management and sustainability research.

Long‐Term Tillage and Compost Shape Soil Microbes Under Soil Organic Carbon Equilibrium

ABSTRACTSoil microorganisms are crucial in regulating soil organic matter dynamics and nutrient cycling, mediating the effects of agricultural management on soil health. Although the microbial responses to changes in soil organic carbon (SOC) are well‐documented, a knowledge gap remains regarding microbial dynamics when soils reach SOC equilibrium. This study investigated how tillage and fertilizer types (compost and mineral fertilizer) influence microbial properties in a continuous corn system with surface soils at SOC equilibrium. We evaluated a 28‐year experiment comparing conventional tillage (CT) and no‐till (NT), combined with either manure or compost (OF), mineral fertilizer (MF), or no nitrogen addition (CO), measuring soil microbial biomass, extracellular enzyme activity, and soil physicochemical properties to a depth of 90 cm. In the 0–5 cm layer under NT‐OF, SOC concentration had stabilized since 2003 despite annual compost additions, indicating a near‐equilibrium state. Upon reaching this threshold, microbial biomass and β‐glucosidase (bG) activity plateaued, suggesting additional organic carbon inputs no longer enhanced these properties but instead contributed to SOC movement into deeper soil horizons, where increased microbial activity was observed. Long‐term CT‐OF resulted in 30% less SOC and total nitrogen compared to NT‐OF, suggesting tillage disrupted SOC accumulation and enhanced decomposition. Both NT‐MF and NT‐CO had minimal effects on microbial properties and SOC, potentially due to insufficient organic residue returned. Although NT‐OF increased SOC, total nitrogen, available phosphorus, and microbial biomass to 30 cm depth, it also reduced oxidative enzyme activity and arbuscular mycorrhizal fungi abundance, indicating shifts in microbial functional strategies in response to the continuous addition of compost. Our study demonstrated that once surface soils reach SOC equilibrium, additional compost additions no longer increased microbial processes in the surface layer but instead promoted SOC translocation to deeper horizons. This dynamic underscores the need for depth‐conscious management strategies that balance soil microbial activity, SOC storage, and the capacity for SOC stabilization across soil profiles.

Functional traits of ectomycorrhizal trees influence surrounding soil organic matter properties

Abstract Ectomycorrhizal (EM) effects on forest ecosystem carbon (C) and nitrogen (N) cycling are highly variable, which may be due to underappreciated functional differences among EM‐associating trees. We hypothesise that differences in functional traits among EM tree genera will correspond to differences in soil organic matter (SOM) dynamics. We explored how differences among three genera of angiosperm EM trees (Quercus, Carya, and Tilia) in functional traits associated with leaf litter quality, resource use and allocation patterns, and microbiome assembly related to overall soil biogeochemical properties. We found consistent differences among EM tree genera in functional traits. Quercus trees had lower litter quality, lower δ13C in SOM, higher δ15N in leaf tissues, greater oxidative extracellular enzyme activities, and higher EM fungal diversity than Tilia trees, while Carya trees were often intermediary. These functional traits corresponded to overall SOM‐C and N dynamics and soil fungal and bacterial community composition. Our findings suggest that trait variation among EM‐associating tree species should be an important consideration in assessing plant–soil relationships such that EM trees cannot be categorised as a unified functional guild. Read the free Plain Language Summary for this article on the Journal blog.

SOIL CARBON SEQUESTRATION THROUGH COVER CROPS AND REDUCED TILLAGE: A CLIMATE-SMART AGRICULTURAL STRATEGY FOR MITIGATING CLIMATE CHANGE AND IMPROVING SOIL HEALTH

In the face of increasing climate change and declining soil health, innovative agricultural strategies are urgently needed. This review highlights the promising synergy between cover crops and reduced tillage practices as a climate-smart approach to enhance soil carbon sequestration and improve soil quality. By delving into the fundamental mechanisms of soil organic matter dynamics, including microbial mediation and carbon stabilization processes, this paper sets the stage for understanding how these practices work together to sequester carbon in soils. Drawing on robust empirical evidence from long-term field experiments and advanced modeling studies, we illustrated how cover crops, through increased residue inputs and enhanced root biomass, and reduced tillage, by preserving soil structure and moisture, together create conditions that favor significant soil organic carbon accumulation and improved nutrient cycling. Moreover, advanced methodologies such as soil sampling protocols, isotopic labeling, and remote sensing integrated with process-based models are reviewed to quantify these benefits accurately. We also explore the economic and environmental dimensions of adopting these practices through life cycle assessments and cost–benefit analyses, which underscore their potential to deliver substantial non-market benefits. Policy implications, including existing incentive structures and barriers to adoption, are critically discussed, along with strategies to overcome these challenges through targeted extension services and stakeholder engagement. This review highlights the future of sustainable farming, emphasizing precision agriculture, genetic advancements, and interdisciplinary research to refine cover cropping and reduced tillage practices. By adopting these strategies, farmers can improve soil health, store more carbon, and build resilient agricultural systems that support both the environment and long-term food security.

Multivariate Insight into Soil Organic Matter Dynamics in Subarctic Abandoned Farmland by the Chronosequence Approach

Agricultural land abandonment is a widespread phenomenon found in many regions of the world. There are many studies on post-agricultural changes in temperate, arid, semi-arid regions, etc., but studies of such soils in boreal or Arctic conditions are rare. Our study aims to fill the gaps in research on the processes of post-agricultural soil transformation, with a focus on the harsh climatic conditions of the Arctic and Subarctic regions. Parameters of soil organic matter (SOM) are largely reflected in the quality of soil, and this study investigates the dynamics of SOM properties in Subarctic agricultural soils in process of post-agrogenic transformation and long-term fertilization. Using a chronosequence approach (0–25 years of abandonment) and a reference site with over 90 years of fertilization, we performed elemental (CHN-O) analysis, solid-state 13C NMR spectroscopy of SOM, PXRD of soil and parent material, and multivariate statistical analysis to identify the connections between SOM composition and other soil properties. The results revealed transient increases in soil organic carbon (SOC) during early abandonment (5–10 years; 3.75–4.03%), followed by significant declines after 25 years (2.15–2.27%), driven by mineralization in quartz-dominated soils lacking reactive minerals for organo-mineral stabilization. The reference site (the Yamal Agricultural Station) maintained stable SOC (3.58–3.83%) through long-term organic inputs, compensating for poor mineralogical protection. 13C NMR spectroscopy highlighted shifts from labile alkyl-C (40.88% in active fields) to oxidized O-alkyl-C (21.6% in late abandonment) and lignin-derived aryl-C (15.88% at middle abandonment), reflecting microbial processing and humification. Freeze–thaw cycles and quartz dominance mineralogy exacerbated SOM vulnerability, while fertilization sustained alkyl-C (39.61%) and balanced C:N (19–20) ratios. Principal Component Analysis linked SOC loss to declining nutrient retention and showed SOM to be reliant on physical occlusion and biochemical recalcitrance, both vulnerable to Subarctic freeze–thaw cycles that disrupt aggregates. These findings underscore the fragility of SOM in Subarctic agroecosystems, emphasizing the necessity of organic amendments to counteract limitations of poor mineralogical composition and climatic stress.

Dynamics of soil organic matter, bulk density and infiltration rate on mining reclamation land

Post-mining land reclamation is carried out to restore the environmental functions of the land. Monoculture and multiculture planting patterns have different impacts on soil’s physical properties. This study aimed to determine the effects of analyzing soil organic matter, bulk density, and measuring soil infiltration rates in monoculture and multiculture planting patterns. The research used survey methods, data analysis through tabulation, and statistical techniques. The results indicated differences in soil physical properties between the two lands and among the variables. Mahayung land exhibited higher organic matter content (1.08%) compared to Banko land (0.66%). Additionally, the average infiltration rate in Mahayung land (3.02 cm/hour) was higher than in Banko land (2.56 cm/hour), and the bulk density in Mahayung land (1.40 g/cm³) was lower than in Banko land (1.62 g/cm³). Organic matter content influenced the infiltration rate by 70.69%, and affected bulk density by 49.39%. Finally, the different planting patterns affect soil physical properties, and the relationships among variables show significant results.

Investigating the Impact of Salinity on Soil Organic Matter Dynamics Using Molecular Biomarkers and Principal Component Analysis

Soil salinity is a growing threat to agricultural sustainability, particularly in arid and semi-arid regions. Understanding how salinity affects soil organic matter (OM) is critical for improving land management and maintaining soil health. This study addresses these challenges by exploring the molecular-level impact of salinity on OM dynamics. Salinity exerts a depth-dependent influence on lignin and microbial lipid biomarkers, which are used to trace plant inputs and microbial activity, respectively. For lignin biomarkers, in the surface layer (0–20 cm), higher salinity levels are associated with increased Syringyl/Vanillyl (S/V) and Cinnamyl/Vanillyl (C/V) ratios, suggesting enhanced preservation of syringyl (S) and cinnamyl (C) units. In the middle layer (−20 to −60 cm), higher salinity correlates with elevated SVC (total lignin phenols), Acid/aldehyde (Ad/Al) ratios, and other markers of selective lignin degradation. For lipid biomarkers, salinity modulates microbial adaptation and turnover, as seen in variations in i17 (iso-C17), a17 (anteiso-C17), and unsaturation indices such as C16:1/C16, reflecting Gram-positive and Gram-negative bacterial activity. These trends indicate that salinity stress alters microbial lipid profiles, leading to reduced turnover and enhanced preservation in deeper, more anoxic environments. Principal Component Analysis (PCA) revealed depth- and salinity-driven patterns that distinguish between surface microbial transformations and deep-layer molecular preservation. Correlation analysis of Principal Components (PCs) with salinity revealed that higher salinity favored molecular stability in deeper layers, while lower salinity was associated with microbial transformations in surface layers. These findings underscore salinity’s critical role in OM stabilization and turnover, and provide a molecular framework to guide sustainable management of saline soils.

Research advances in the impacts of ectomycorrhizal fungi on the formation and decomposition of soil organic matter in forests.

Ectomycorrhizal (EcM) fungi are one of the important functional groups of soil fungi, playing a crucial role in the formation, stabilization, and decomposition of soil organic matter (SOM). We summarized the main processes and mechanisms by which EcM fungi contribute to SOM formation, stabilization, and decomposition in forests. Plants allocate a portion of photosynthetic products to symbiotic EcM fungi, which participate in SOM formation by importing them into the soil in the form of mycorrhizal exudates or necromass, whose activities promote the formation of soil aggregate structure and SOM stabilization. EcM fungi decompose SOM directly by secreting extracellular enzymes or by driving the Fenton reaction to generate hydroxyl radicals. They also influence SOM decomposition indirectly by enhancing the activity of saprotrophic fungi (priming effect) or inhibiting their activity (Gadgil effect). The precise quantification of EcM fungi's role in SOM formation remains unclear. Most available studies are concentrated in Europe and North America, but the difference in methodologies makes it difficult to integrate data across regions. Future research should adopt standardized techniques and promote cross-regional collaborative studies. Current understanding of EcM fungi's role in SOM decomposition is mainly based on a few laboratory-cultured species. Future studies should include a broader range of EcM fungal species and investigate their roles in natural environments, particularly in different soil types and forest communities. In addition, the interactions between EcM fungi and saprotrophic fungi have significant impacts on SOM dynamics. Future research should explore the responses of EcM fungi to climate, soil and vegetation in depth to better understand their role in soil carbon cycling.

Correction to “BLOSOM: A Plant Growth Facility Optimised for Continuous 13C Labelling and Measurement of Soil Organic Matter Dynamics”

Correction to “<scp>BLOSOM</scp>: A Plant Growth Facility Optimised for Continuous <scp>¹³C</scp> Labelling and Measurement of Soil Organic Matter Dynamics”

A Bibliometric Analysis of Research on the Sources and Formation Processes of Forest Soil Organic Matter Under Climate Change

Forest soil organic matter (SOM) is a critical component of forest ecosystems and plays a vital role in the global carbon (C) cycle. Global climate change profoundly affects forest SOM dynamics, particularly its sources and formation processes, which are crucial initial stages of the forest soil C cycle. Therefore, understanding these processes and the impacts of climate change is essential for developing effective forest management strategies and climate policies. In this study, VOSviewer 1.6.18 was used to conduct a bibliometric analysis of research published from 1975 to 2024, retrieved from the Web of Science (WoS) Core Collection database, focusing on the sources and formation processes of forest SOM under climate change. The analysis covers annual publication trends, author co-occurrence networks, publication distributions by country and region, keyword clustering, and evolving keyword trends, integrating both quantitative results and a literature review to provide an understanding of the research progress in the field. The results highlight continuous growth in research publications, which can be categorized into four stages: initial emergence, sustained exploration, rapid development, and deep expansion. A solid theoretical foundation and good research strength have been established, driven by prominent academic groups led by researchers such as Jari Liski, as well as leading countries, including the United States and China. The research progress is divided into four topics: the sources of forest SOM; the formation processes of forest SOM; the impacts of climate change; and measurement methods and model-based analysis techniques, which mainly elaborate upon plant-, microbial-, and soil fauna-derived aspects. Research hotspots have evolved from basic C and nitrogen (N) cycles to in-depth studies involving microbial mechanisms and multiparameter climate change interactive effects. This study provides an overview of the research progress and hotspots in the field, offering basic knowledge and theoretical support for potential future research and climate change mitigation strategies.

The Kerbernez long-term experiment: A dataset on crop yield and soil organic matter evolution in forage crop rotations and permanent grasslands in a temperate oceanic climate.

Forage crop rotations including grasslands, common in dairy systems, are known to ensure good productivity and limit the decrease of soil organic matter frequently observed in permanent arable land. A dataset was built to compile data from the Kerbernez long-term experiment, conducted in Brittany(France) from 1978 to 2005. This experiment compared the effect of different forage crop rotations fertilized with ammonium nitrate and/or slurry, with or without grassland, on forage production (quantity, quality) and changes in soil physio-chemical characteristics. These forage crop rotations were based on silage maize and cut monospecific grasslands of Italian ryegrass (Lolium multiflorum L.) or perennial ryegrass (Lolium perenne L.). More precisely, the experiment compared silage maize monocultures, rotations with silage maize and Italian ryegrass established for 6 to 18 months, and rotations with silage maize and perennial ryegrass established for three to more than 10 years. They are representative of the forage crop rotations and permanent grasslands that were at the heart of Brittany's forage revolution in the 1970s. The dataset includes information about the climate and soil conditions, the management of crops and grasslands, the evolution of topsoil organic carbon and nitrogen stocks, the inter-annual variations in crop and grassland dry matter yields and nitrogen contents. The dataset also includes characterisation of soil structural stability, particle-size soil organic matter fractions and potential soil carbon and nitrogen mineralisation at the end of the trial. It consists of fourteen csv files. This dataset can be used for a variety of purposes, namely for assessing the ability of mechanistic models to simulate soil organic matter dynamics and associated fluxes, and to estimate the influence of grassland presence and duration in forage crop rotations on such fluxes.

Depth‐Distribution Patterns of Soil Organic Matter in the Tidal Marshes of the Venice Lagoon (Italy): Signatures of Depositional and Environmental Conditions

Abstract Salt marshes are depositional landforms lying at the upper margin of intertidal environments. They provide a diverse range of valuable ecosystem services and yet are exceptionally vulnerable to climate change and human pressure. Salt marshes are intrinsically dynamic environments, shaped by complex feedback between hydrodynamic, morphological, and biological processes. Soil Organic Matter (SOM) has a crucial role within salt marsh environments, as on the one hand, its accumulation contributes to the build‐up of marsh elevation which is necessary for marshes to keep pace with sea‐level rise, and on the other it supports the high carbon sink potential of wetlands. To better understand variations in SOM depth distribution and further comprehend SOM drivers, we analyzed soil organic content in 10 salt marshes of the microtidal Venice Lagoon from 60 sediment cores to the depth of 1 m, relating SOM spatial and vertical patterns to the temporal and spatial variability of depositional sub‐environments recorded in the study deposits. Our results suggest that changes in the depositional environment are of primary importance in determining organic matter depth distribution and caution is needed in SOM prediction at unsampled soil depths. We observed relationships between SOM vertical patterns and factors such as autochthonous and allochthonous organic inputs, sediment properties, relative sea level rise, fluvial inputs and wave action. Our findings emphasize the considerable carbon storage potential of marshes in intertidal environments and provide a conceptual framework for understanding the dynamics of SOM and their drivers, which can inform and enhance coastal management strategies.

Author Correction: A landscape-scale view of soil organic matter dynamics

Author Correction: A landscape-scale view of soil organic matter dynamics

A landscape-scale view of soil organic matter dynamics

A landscape-scale view of soil organic matter dynamics

Soil carbon, organic matter fractions, and soil physical quality under different sugarcane harvesting systems in north-east Brazil

Context Sugarcane cultivation is one of the main agricultural activities in Brazil. Among the production systems, unburnt harvesting has gained prominence and has been replacing the burning system. The use of unburnt harvesting system increases straw retention on soil surface, which influences the quantity and quality of soil organic matter (SOM). Aims We evaluated the effects of burnt and unburnt sugarcane harvesting systems on soil organic carbon (SOC) stocks and SOM dynamics in the north-east region of Brazil. Methods The study was conducted at three sites, each containing one area of burnt sugarcane harvesting system (Bs), two areas of unburnt sugarcane harvesting systems (Us) and one area of native vegetation (NV), totaling 12 collection sites. Key results The results show that the conversion of NV to sugarcane cultivation areas led to SOC loss, which ranged from 7% to 62%, and reduced soil quality due to losses of particulate organic matter (POM) and increased soil bulk density (BD), being corroborated by changes in other indicators, such as soil degree of compactness (SDC), and reduction in the soil structural stability index (SSI). Conclusions Despite the losses when compared to NV, the Us system showed increments in SOC, POM-C, and SSI and reductions in BD and SDC compared to Bs. Implications The findings of this study highlight the importance of understanding the impact of land use change on the properties of SOM.

BLOSOM: A Plant Growth Facility Optimised for Continuous 13C Labelling and Measurement of Soil Organic Matter Dynamics

ABSTRACTChanges in soil carbon (C) stocks are largely driven by rhizosphere processes forming new soil organic matter (SOM) or stimulating SOM decomposition by rhizosphere priming effects (RPEs). Quantifying these changes is challenging and requires high spatial sampling densities or plant–soil experiments with highly distinct C isotopic signatures for plants and soils. Current methods for quantifying new SOM formation and RPEs rely on low labelling intensities, which introduces high levels of uncertainty. Here, we describe the design and operation of an experimental laboratory facility—BLOSOM (Botanical Labelling Observatory for Soil Organic Matter)—optimised for continuous 13C labelling of plants at high labelling intensities (&gt; 500‰) to quantify new SOM formation and RPEs in temperature‐controlled soils from 216 experimental units. Throughout a &gt; 6‐month experimental period, independent control of soil and air temperature was achieved across diurnal cycles averaging at 5.24°C ± 0.05°C and 21.4°C ± 1.2°C, respectively. BLOSOM can maintain stable CO2 concentrations and δ13C isotopic composition within 5% of setpoints (CO2: 440 ppm, δ13C: 515‰) across a &gt; 6‐month period. This high‐precision control on atmospheric enrichment enables the detection of new SOM formation with a total uncertainty of ±39% to ±3% for a theoretical range of 0.5%–10% new SOM formation, respectively. BLOSOM has the potential improve quantification and mechanistic understanding of new SOM formation and RPEs across many different combinations of plants, soils and simulated climatic conditions to mimic a wide range of ecosystems and climate scenarios.

Modern Development of Soil Organic Matter Dynamics Models (Review)

Soils are the largest terrestrial reservoir of organic carbon, and so even small changes in soil carbon stocks can have significant effects on the atmosphere and climate. To select effective strategies to mitigate climate change, predictions of how soils will respond to future changes in climate and land use are needed. Achieving meaningful predictions requires a deep understanding of the highly complex, open, multicomponent soil organic matter system. One of the most effective methods for predicting the dynamics of soil organic matter is mathematical modeling. Process-oriented (physically based) models make it possible to present the basic concepts about the mechanisms that determine the behavior of this system in a mathematically formalized form and conduct a quantitative analysis. The uncertainty of the forecasts depends on the level of development of the theory explaining the dynamics of soil organic matter, the models representing it and their experimental support. This review examines the achievements of the last decade in modeling the role of microorganisms in the stabilization of soil organic matter, the concept of soil saturation with organic carbon, and temperature control, as well as the development of reactive transport models describing the dynamics of organic carbon in the soil profile and the representation of the dynamics of soil organic matter in global climate models. Unsolved problems associated with the high variability in the structure of new generation soil organic matter dynamics models are discussed.

Cropping and soil management systems effects on soil organic matter fractions in diversified agricultural fields in the Cerrado

ABSTRACT Soil organic matter (SOM) dynamics can be significantly influenced by various cultivation practices, particularly under environmental and edaphic conditions that enhance and accelerate the transformations of organic materials such as straw, root biomass, and organic fertilizers. This study aimed to evaluate the impact of different cultivation and soil management systems on SOM fractions in agricultural areas of the Cerrado Goiano region. The research was conducted across three areas with diverse production systems: 1) BV area, including soybean monoculture (SM01), integrated crop-livestock-forest (ICLF01), pasture (PA01), and Cerrado vegetation (NV01); 2) ML area, featured soybean-corn monoculture succession (SMS02), agroforestry (AF02), pasture (PA02), and native Cerrado vegetation (NV02); and 3) IF area, comprised soybean-corn succession (SMS03), integrated livestock-forest (ILF03), pasture (PA03), and native Cerrado vegetation (NV03). Disturbed and undisturbed soil samples were collected from two layers: 0.00-0.05 and 0.05-0.10 m. Samples were analyzed for total organic carbon, carbon storage, and SOM physical (granulometric and densimetric) and chemical (fulvic acid, humic acid, and humin) fractionations of soil organic matter (SOM). Additionally, water-floatable light organic matter (LOM), the carbon management index, and its components were determined. Soil organic matter fractions were similarly influenced by the characteristics of cultivation and management systems. However, there were more pronounced differences between systems in the BV area compared to the ML and IF areas. Among the parameters studied, LOM proved to be the most efficient and effective in distinguishing SOM input across different cultivation and soil management systems, particularly in pasture systems.

Modern development of soil organic matter dynamics models (review)

Soils are the largest terrestrial reservoir of organic carbon, so even small changes in soil carbon stocks can have significant effects on the atmosphere and climate. To select effective strategies to mitigate climate change, predictions of how soils will respond to future changes in climate and land use are needed. Achieving meaningful predictions requires a deep understanding of the highly complex, open, multicomponent soil organic matter system. One of the most effective methods for predicting the dynamics of soil organic matter is mathematical modeling. Process-oriented (physically based) models make it possible to present the basic concepts about the mechanisms that determine the behavior of this system in a mathematically formalized form and conduct a quantitative analysis. The uncertainty of the forecasts depends on the level of development of the theory explaining the dynamics of soil organic matter, the models representing it and their experimental support. This review examines the achievements of the last decade in modeling the role of microorganisms in the stabilization of soil organic matter, the concept of soil saturation with organic carbon, temperature control, as well as the development of reactive transport models describing the dynamics of organic carbon in the soil profile, and the representation of the dynamics of soil organic matter in global climate models. Unsolved problems associated with the high variability in the structure of new generation soil organic matter dynamics models are discussed.