Carbon Fractions Research Articles

Investigating the complementarity of thermal and physical soil organic carbon fractions

Abstract. Partitioning soil organic carbon (SOC) in fractions with different biogeochemical stability is useful to better understand and predict SOC dynamics and provide information related to soil health. Multiple SOC partition schemes exist, but few of them can be implemented on large sample sets and therefore be considered relevant options for soil monitoring. The well-established particulate organic carbon (POC) vs. mineral-associated organic carbon (MAOC) physical fractionation scheme is one of them. Introduced more recently, Rock-Eval® thermal analysis coupled with the PARTYSOC machine learning model can also fractionate SOC into active (Ca) and stable SOC (Cs). A debate is emerging as to which of these methods should be recommended for soil monitoring. To investigate the complementarity or redundancy of these two fractionation schemes, we compared the quantity and environmental drivers of SOC fractions obtained on an unprecedented dataset from mainland France. About 2000 topsoil samples were recovered all over the country, presenting contrasting land cover and pedoclimatic characteristics, and analysed. We found that the environmental drivers of the fractions were clearly different, the more stable MAOC and Cs fractions being mainly driven by soil characteristics, whereas land cover and climate had a greater influence on more labile POC and Ca fractions. The stable and labile SOC fractions provided by the two methods strongly differed in quantity (MAOC/Cs=1.88 ± 0.46 and POC/Ca=0.36 ± 0.17; n=843) and drivers, suggesting that they correspond to fractions with different biogeochemical stability. We argue that, at this stage, both methods can be seen as complementary and potentially relevant for soil monitoring. As future developments, we recommend comparing how they relate to indicators of soil health such as nutrient availability or soil structural stability and how their measurements can improve the accuracy of SOC dynamics models.

Characteristics of soil organic carbon fractions and influencing factors in different understory mosses in karst urban parks

Characteristics of soil organic carbon fractions and influencing factors in different understory mosses in karst urban parks

Novel long pulse potassium-titanyl-phosphate with substructured pulses – An effective tool in treating post-inflammatory erythema: A report of two cases in darker skin

The utilization of lasers is advancing as the range of applications for laser therapy expands, and new devices have been introduced. Vascular coagulation, pigment ablation, skin regeneration, tissue cutting or ablation, and hair removal are the five primary applications of laser therapy for the treatment of dermatological conditions. We present two cases of female patients with bilateral facial redness, one due to electromedical plasmage and the other from fractional carbon dioxide (CO2) laser, in which the target of their therapy was to improve acne scarring. Facial redness in both cases was successfully treated using a potassium-titanyl-phosphate (KTP) laser with cryogen cooling. The KTP laser has demonstrated efficacy in treating erythema associated with various conditions, including CO2 fractional laser and plasmage therapy. One of the advantages of the KTP laser is that it minimizes post-operative purpura and erythema, making it a favorable option for treating erythema itself.

Edge Influence in a Semi‐Deciduous Tropical Forest: An Investigation of Soil Organic Carbon Fractions

ABSTRACTRecent studies have proven the sensitivity of soil organic carbon (SOC) in responding to variations imposed by tropical forest fragmentation, which may reflect changes in both its quantity and quality. Despite this, studies evaluating soil carbon fractions as an edge effect indicator are still non‐existent. We developed this work asking: How do the oxidizable fractions of soil organic carbon (OFSOC) respond to the edge effect in fragments of semi‐deciduous seasonal forest? Is this response influenced by the size of the forest fragment? The study was conducted in Vitória da Conquista, Bahia, Brazil, in three forest fragments with different sizes. Thus, three sampling sections were defined in each fragment: edge (0–10 m), transition (40–50 m), and interior. Soil samples were collected at a depth of 0–10 cm. The SOC was divided into three fractions (LC—labile carbon, MLC—moderately labile carbon, and LLC—low labile carbon), adopting the chemical method based on oxidation degrees. Reductions in the SOC (28.2%), LC (17.4%), and MLC content (66.7%) were observed at the edge in the small fragment. There was a reduction of SOC (21.3%) and LLC (39.0%) at the edge in the medium fragment, while MLC showed an increase at the edge (70.4%). The OFSOC were able to respond to the changes imposed by the edge effect, with emphasis on the LC and MLC fractions in smaller fragments. The forest fragment size influenced the level of changes caused by the edge effect in OFSOC, showing greater susceptibility in smaller fragments.

Efficacy and safety of sequential treatment with botulinum toxin type A, fractional CO2 laser, and topical growth factor for hypertrophic scar management: a retrospective analysis

Hypertrophic scars arise from aberrant wound healing and can lead to functional and aesthetic impairments. One of the common interventions for treating hypertrophic scars is fractional carbon dioxide (CO2) laser, which employs narrow laser beams to stimulate dermal collagen deposition. Recent studies and reports have suggested that combining laser therapy with other interventions such as botulinum toxin type A (BTX-A) and topical growth factors may enhance treatment outcomes. Here, we examine the efficacy and safety of a sequential combination of BTX-A, fractional CO2 laser, and topical growth factors, referred to as combined therapy, for treating hypertrophic scars compared with only using fractional CO2 laser and topical growth factors, referred to as monotherapy. Our retrospective study includes 128 patients with hypertrophic scars (56 underwent monotherapy and 72 underwent combined therapy), which were followed-up for up to 15 months after the initiation of treatment to collect demographic and clinical data. Our analysis showed that the combined therapy significantly outperformed monotherapy in improving Vancouver scar scale scores (P < 0.05) and in the reduction of scar thickness (P < 0.05), without increasing adverse complications. Repeated treatments further augmented the efficacy of the combined therapy. Subgroup analysis revealed that combined therapy was notably more effective in reducing Vancouver scar scale scores and scar thickness in early-stage scars compared to late-stage (P = 0.023 and P = 0.045, respectively). Our study suggests that including BTX-A treatment before fractional CO2 laser and topical growth factors offers superior efficacy in reducing hypertrophic scars. We encourage early intervention and repeated treatments for optimal treatment outcomes.

The Fungal Community Structure Regulates Elevational Variations in Soil Organic Carbon Fractions in a Wugong Mountain Meadow

Soil organic carbon (SOC) fractions are vital intrinsic indicators of SOC stability, and soil fungi are the key drivers of soil carbon cycling. However, variations in SOC fractions along an elevational gradient in mountain meadows and the role of the fungal community in regulating these variations are largely unknown, especially in subtropical areas. In this study, an elevation gradient experiment (with experimental sites at 1500, 1700, and 1900 m) was set up in a Miscanthus sinensis community in a meadow on Wugong Mountain, Southeast China, to clarify the effects of elevation on soil fungal community composition, microbial residue carbon, and SOC fractions. The results showed that the contribution of soil microbial residue carbon to SOC was only 16.1%, and the contribution of soil fungal residue carbon to SOC (15.3%) was far greater than that of bacterial residue carbon (0.3%). An increase in elevation changed the fungal community structure and diversity, especially in the topsoil (0–20 cm depth) compared with that in the subsoil (20–40 cm depth), but did not affect fungal residue carbon in the two soil layers. When separating SOC into the fractions mineral-associated organic carbon (MAOC) and particulate organic carbon (POC), we found that the contribution of MAOC (66.6%) to SOC was significantly higher than that of POC (20.6%). Although an increased elevation did not affect the SOC concentration, it significantly changed the SOC fractions in the topsoil and subsoil. The soil POC concentration and its contribution to SOC increased with an increasing elevation, whereas soil MAOC showed the opposite response. The elevational variations in SOC fractions and the POC/MAOC ratio were co-regulated by the fungal community structure and total nitrogen. Our results suggested that SOC stabilization in mountain meadows decreases with an increasing elevation and is driven by the fungal community structure, providing scientific guidance for SOC sequestration and stability in mountain meadows in subtropical areas.

Late Glacial and Holocene history of climate, vegetation landscapes and fires in South Taiga of Western Siberia based on radiocarbon dating and multi-proxy palaeoecological research of sediments from Shchuchye Lake

Abstract To investigate long-term relationships between climate, vegetation, landscape geochemistry and fires in the boreal forest zone of Western Siberia, a sediment core of 345 cm was collected from Shchuchye Lake (located in south taiga zone of southeast part of West Siberian plain) and investigated by spore-pollen, radiocarbon, LOI and charcoal analyses. Quantitative palaeoclimate was reconstructed based on pollen data. Investigation revealed 13.2 cal ka history of vegetation, climate, landscapes and fires. In the dry climate of Late Glacial, the landscape was treeless. Continuous permafrost existed in the soil. In the middle of the YD cooling 12.4–12.2 cal ka BP, our data showed warming that caused degradation of permafrost in soils and settlement of spruce in moist places. Later, thawing and accumulation of moisture in a local lowering in relief increased and a lake was formed. With the beginning of the Holocene, the climate sharply changed to warmer and wetter. Intensified surface flow caused accumulation of mineral and carbonate fraction in the lake. Dense birch forests spread on drylands. As a result, the leaching regime initiated the formation of podzols in the soil. At about 10.0 cal ka BP, Scots pine (Pinus sylvestris) quickly spread in the area of investigation. Fires became more frequent and more intense during the dry Late Glacial time, sharply decreasing with increased precipitation in the Early Holocene, and again moderately increasing with spread of pine forests in the mid Holocene. With the transition to Late Holocene (after 6.0 cal ka BP), the intensity of regional background fires and number of local fires decreased.

Improving the method for calculating carbon emissions from waste incineration: confirmed with carbon-14 testing of flue gas

An improved method was developed to calculate direct emissions from seven municipal solid waste incineration plants by adjusting the physical compositions of waste by invoking the proportion of co-incinerated waste and the bottom ash yield. The fossil carbon fractions of the waste components were determined by carbon-14 (14C) testing. Based on the improved method, direct emissions were in the range of 222–610 kg CO2-eq/t waste, corresponding to reductions of 3.4–221 kg CO2-eq/t waste compared with the method without waste composition adjustment. The 14C contents of the flue gas before and after gas cleaning were tested to validate the improved method, and indicated fossil CO2 emissions of 249–446 and 233–405 kg CO2-eq/t waste, respectively. The direct emissions obtained by the improved method were closer to the results of 14C testing, due to more accurate estimations of the actual waste composition. The method was further combined with a life cycle analysis of the waste incineration process, obtaining total carbon emissions in the range from –33.2 to 483 kg CO2-eq/t waste. The findings provide a new means of accurately calculating carbon emissions from waste incineration.Graphical

Estimating the Greenhouse Gas Emission Potential Due to Construction Work on the 225 kV Segou - Bamako High Voltage BI-Ternal Electric Line in Mali in The Context of Climate Change

The aim of this study is to assess the carbon emissions resulting from the construction of the power line linking Bamako to Ségou. It focuses on direct emissions, more specifically those linked to the degradation and desctruction of the vegetation cover in the project right-of-way. To collect the data, surveys were set up on the project right-of-way, through which 3302 trees were inventoried in situ at the three sites. Circumference was measured at 1.30 m from the ground surface. Allometric equations for direct biomass estimation were used as a predictor o f tree diameter. Emission factors were then used to estimate the potential greenhouse gas emissions resulting from tree felling during power line construction. The standard error associated with the carbon fraction in dry biomass was calculated. In the Ségou, Koulikoro and Dioïla project areas, there are a number of plant species that provide local populations with various ecosystem services, including micro-climate regulation through carbon sequestration or absorption of atmospheric CO2. The implementation of the project will undoubtedly result in the felling of these trees. This felling will generate emissions of 22.11 t.eqCO2/ha in Ségou, 16.56 t.eqCO2/ha in Koulikoro and 15.43 t.eqCO2/ha in Dioïla. Across Ségou, Koulikoro and Dioïla, the trees in the project right-of-way represent a reservoir of 34.04 t/ha of above-ground woody biomass. This biomass represents a carbon stock of around 16.58 t.C/ha. This carbon stock will be transformed into a carbon source with emissions of 60.78 t.eqCO2/ha if the trees in the power line right-of-way are systematically felled. Mitigation measures are therefore urgently needed, with compensatory reforestation areas planted with species with high carbon sequestration potential.

Regulation of wheat yield by soil multifunctionality and metagenomic-based microbial degradation potentials under crop rotations

Crop rotation benefits soil fertility and crop yield by providing organic components including cellulose, lignin, chitin, and glucans that are mainly degraded by soil microbial carbohydrate-active enzymes (CAZymes). However, the impacts of crop rotation on soil microbial CAZyme genes are not well understood. Hence, CAZyme genes and families involved in the degradation of differentially originated organic components were investigated using metagenomics among distinct crop rotations. Crop rotation had a more significant effect on soil nitrogen than on carbon fractions with higher content in the complex rotation referring to alfalfa (Medicago sativa L.; 4 year)-potato (Solanum tuberosum L.; 1 year)-winter wheat (3 year; A4PoW3). The composition of soil microbial CAZyme genes related to the degradation of fungi-derived components was more affected by crop rotation compared with the degradation of plant- and bacteria-derived components. The total abundance of CAZyme genes and families was significantly higher in the complex rotation. Notably, CAZyme genes belonging to glycoside hydrolase and glycosyl transferase families had more connections in their network. Moreover, key genes including CE4, GH20, and GH23 assembled toward the middle of the network, and were significantly regulated by dominant soil nitrogen fractions including soil potential nitrogen mineralization and microbial biomass nitrogen. Soil multifunctionality was mostly explained by the composition and total abundance of CAZyme genes, but wheat grain yield was profoundly regulated by fungi-derived components degradation genes under effects of dominant nitrogen fractions. Overall, the findings provide deep insight into the degradation potentials of soil microbial CAZyme genes for developing sustainable crop rotational agroecosystems.

Determinants of rhizospheric organic carbon fractions and accumulation in four different vegetations of coastal saline-alkali soils

Rhizosphere processes are key pathways through which plants influence the carbon cycling of diverse ecosystems and are closely associated with vegetation types. However, the environmental responses of rhizospheric soil organic carbon (SOC) mediated by the interaction between rhizospheric effect and vegetation type remain uncertain, severely limiting our assessment of the carbon sequestration potential of different coastal vegetation. Here, we identified the core factors driving changes in various soil carbon fractions in the rhizosphere of four coastal vegetation types by testing the contents of the reactive, dissolved, particulate, mineral-associated, heavy and light fractions of SOC and their relationships with physicochemical properties and enzyme activities. It was found that the rhizosphere effect significantly influenced SOC, with rhizospheric SOC contents varying significantly among vegetation types, ranging from 2.12 to 9.04 g/kg. Besides, rhizospheric soil pH was found to contribute significantly to SOC fractions (except for light organic carbon) and exert significant inhibitory effects on SOC, reactive organic carbon, mineral-associated organic carbon and heavy organic carbon. Despite the different responses of various SOC fractions to physicochemical properties and enzyme activities, soil available phosphorus and alkaline phosphatase activity emerged as core environmental factors influencing rhizospheric SOC accumulation across different coastal vegetation types. This study presents a promising framework for understanding the determinants of SOC fractions in rhizospheric soil, and their accumulation in the vegetation of coastal saline-alkali soils. In addition to alkalinity, phosphorus acquisition capacity can be a key predictor of coastal SOC fractions and their accumulation.

Impacts of shifting from single-species pine forests to distinct agroforestry models on soil fertility, exchangeable cations, and microbial functions

The transition from monoculture to mixed-species agroforestry systems affects soil organic matter and microbial activity. However, the specific dynamics of these changes, particularly within medicinal plant-based agroforestry, remain underexplored. This study investigates the impact of monoculture Pine (Pinus massoniana) forests and four agroforestry models: (M1) Pinus massoniana and Alpina oxyphylla, (M2) Pinus massoniana and Ficus simplicissima, (M3) Pinus massoniana and Amomum villosum, and (M4) Pinus massoniana and Curcuma longa on soil properties and microbial activity in rhizosphere and non-rhizosphere environments. Our results showed significantly higher pH (4.80) and total nitrogen (N) content (1.77 g kg−1) in the rhizosphere of model (M4) compared to (CK). Total organic carbon (TOC) and carbon fractions (POC, DOC, and MBC) also differed significantly across monoculture and agroforestry models, with highest TOC concentrations (31.70 g kg⁻1) in rhizosphere of CK. Exchangeable cations, including Ca2⁺, and Mg2⁺ were significantly higher in the rhizosphere of agroforestry models compared to CK, particularly in M4, where Ca2⁺ was recorded at 12.03 cmol kg−1 with the highest percent base saturation (PBS) at 90.17%. Enzymes leucine aminopeptidase and polyphenol oxidase varied significantly, with higher activity in the rhizosphere of agroforestry models and greater activity in non-rhizosphere of monoculture. Soil microbial respiration (MRes) revealed substantial differences, with an average 17% decrease in rhizosphere soil for models M2 and M4 and a 20.83% reduction in non-rhizosphere soil for model M1 compared to CK. Generalized Linear Model (GLM) demonstrated a significant positive correlation between TOC and MRes (R2 = 0.885, p < 0.01), indicating that higher TOC levels are linked with increased MRes. In conclusion, model M4 most effectively enhanced soil fertility and nutrient availability followed by the other agroforestry models tested. This suggests that integrating medicinal plants into agroforestry systems is a viable strategy for improving ecosystem functioning compared to monoculture practices.

Impact of organic carbon composition on bacterial taxa assembly upon phosphorus addition in organic and mineral soil layers of a Robinia pseudoaccacia plantation

Increasing phosphorus (P) inputs significantly affect the nutrient cycle of terrestrial ecosystems. The community structure and assembly processes of soil bacteria, which are the primary participants in nutrient cycling within terrestrial ecosystems, are affected by P inputs. However, the assembly processes and driving mechanisms of soil bacterial communities in artificial forest ecosystems in response to P inputs remain unclear. Therefore, in this study, we conducted in situ experimental P additions (0, 0.5, 1, 2, and 4 g P m-2 year-1) to artificial Robinia pseudoacacia forests on the Loess Plateau. We investigated the effects of P addition on the soil organic carbon (SOC) composition, bacterial community characteristics (total, abundant, and rare taxa), and assembly processes in the organic horizon (OH) and mineral horizon (MH) layers of the soil. The results showed that P addition significantly changed soil physicochemical factors, such as available P (AP), SOC content, and SOC composition in terms of the labile (LC) and recalcitrant carbon (RC) fractions. The proportion of the LC fraction increased in OH and decreased in MH, whereas the RC fraction showed the opposite trends. P addition increased the proportion of eutrophic bacteria in OH, whereas it decreased the proportion of oligotrophic bacteria. In contrast to those in OH, the changes in eutrophic and oligotrophic bacteria in MH exhibited the opposite trend. With increasing P levels, the diversity of the bacterial communities in the OH did not change significantly. In the MH, total and rare taxa diversity increased, while the diversity of abundant taxa decreased. During P addition, the total and rare taxa bacterial communities showed stochastic assembly, whereas the assembly of abundant taxa shifted from stochastic to deterministic processes in the OH and from deterministic to stochastic processes in the MH. The structural equation model revealed that during P addition, the assembly of total and rare bacterial communities in the OH and MH was regulated by AP and the LC fraction, respectively. Meanwhile, the assembly of abundant taxa in OH and MH was influenced by the LC fraction and RC fraction, respectively. Our findings highlight the critical role of SOC composition across different bacterial taxa, with abundant bacterial taxa exhibiting heightened sensitivity to environmental filtration and the availability of SOC resources. Our study provides new insights into the community assembly and driving mechanisms of soil bacteria in artificial forest soils during P addition.

A case of resistant granuloma faciale successfully treated with ablative fractional carbon dioxide laser

ABSTRACT Granuloma faciale is a benign and rare skin disease, which usually presents as well-defined red-purple asymptomatic plaques or nodules on the face but can also present extra-facially. It poses a significant therapeutic challenge, with varying degrees of success reported by a range of medical and surgical treatments. We describe a 41-year-old lady with biopsy-confirmed facial granuloma faciale, affecting her nose, cheeks, upper lip, and forehead, who had failed a variety of medical treatments, UVB phototherapy, and pulsed dye laser. She was successfully treated with ablative fractional CO2 laser, with a sustained response, without recurrence or complications maintained for 1 year.

Analytical justification of the thermochemical interaction between blast reagents and carbon-containing products under the influence of magnetic fields

Purpose. To justify and develop a model that describes the effect of magnetic treatment of blast reagents and carbon-containing products on the gasification process for predicting the intensification of gas formation. Methodology. The study involves theoretical modeling based on experimental data to investigate the influence of magnetic fields on the underground coal gasification process and co-gasification of coal and carbon-containing products. The Arrhenius equation was used to estimate the rate constants of gasification reactions in the temperature range of 800–1,000 °C. The effect of the magnetic field was incorporated by adjusting the activation energy (Ea). The results of analytical and experimental studies were processed using methods of computer and mathematical modeling. Findings. The results show that the application of magnetic fields significantly intensifies the gasification process of carbon containing products. Increasing the reactivity of the blast reagents, particularly water and oxygen, leads to a higher overall yield of combustible gases. The use of magnetic fields in the gasification process substantially increases the reaction rate (k) due to the reduction in activation energy (Ea), improving the overall efficiency of gasification. Originality. For the first time, an analytical model has been developed to describe the effect of magnetic treatment of blast reagents and carbon-containing products on the gasification process in the temperature range of 800–1,000 °C. The obtained reaction rates follow an exponential trend. The established and correlation-validated pattern shows the relationship between changes in the approximation coefficient (F ) and the change in the carbon fraction (C, %) during the magnetic treatment of blast components within the specified temperature range. Practical value. The results of this study can be applied to enhance the efficiency of industrial gasification processes, particularly underground coal gasification and co-gasification of coal and carbon-containing productss.

Knowledge Structure and Trends of Vitiligo From 2002 to 2023: A Bibliometric Analysis

Introduction: Vitiligo is a common acquired depigmenting dermatosis resulting from a loss of epidermal melanocytes. The academic attention to vitiligo has gradually increased over the past two decades. Objective: We aimed to explore the current research structure and trends of vitiligo. Methods: Publications about vitiligo from the Web of Science Core Collection (WoSCC) database were searched. VOSviewer, CiteSpace, GraphPad Prism 8, ArcGIS, and Charticulator were implemented for data description and visual analysis. Results: A total of 3,037 publications authored by 10,993 individuals from 2,753 institutions across 88 countries/regions were collected. These publications were published in 616 journals and cited a total of 39,433 references. China was the most productive country. Cairo University and Ezzedine Khaled were the most prolific institution and author, respectively. Additionally, the British Journal of Dermatology stood out as the journal with the highest number of publications. According to the analysis of keywords and references, “quality of life,” “depression,” and “validation” were hotspots in terms of clinical characteristics, while “prevalence”, “comorbidity,” “association,” and “immunotherapy” gained more research interest with respect to epidemiology and genetics. The frontiers of pathogenesis focused on “unfolded protein response,” “migration,” “biomarkers,” and “CXCL10.” As far as treatment is concerned, there was increasing attention to “janus kinase inhibitor,” “fractional carbon dioxide laser,” “platelet-rich plasma,” and “5-fluorouracil.” Conclusion: The bibliometric analysis elucidates the foundational knowledge structure on research forces and unveiled the hotspots and frontiers, aiding researchers in gaining a deeper comprehension of the future development trends in the field of vitiligo.

Triple combination of fractional carbon dioxide laser, 308-nm excimer lamp, and platelet-rich plasma in refractory vitiligo: A randomized split-body comparative study

Objectives: Vitiligo significantly impacts patients’ quality of life. Current evidence indicates that combination therapy results in faster improvement, enhancing patient adherence to treatment and leading to higher satisfaction among patients. In this study, we compare the efficacy of combined fractional carbon dioxide (FCO2) laser and excimer lamp with platelet-rich plasma (PRP) or topical tacrolimus in patients with refractory vitiligo. Material and Methods: This is a prospective, single-blind, randomized split-body clinical trial involving 41 patients with resistant focal patches of vitiligo vulgaris. Each patient had two similar lesions randomly assigned to receive either a combination of FCO2 laser, excimer lamp, and intradermal PRP injections or a combination of FCO2 laser, excimer lamp, and topical 0.1% tacrolimus (applied twice daily for 12 weeks). The FCO2 laser and PRP treatments were administered in three monthly sessions, and the excimer lamp was used twice a week over 12 weeks. The efficacy of treatment was assessed based on the physician’s assessment and patient’s satisfaction Results: Despite significant improvement in both treatment groups during the course of treatment, the PRP group showed significantly superior efficacy (more than 50% improvement) compared to the tacrolimus group (56.1% and 26.8%, respectively). Furthermore, the PRP group exhibited greater improvement in resistant acral areas compared to the tacrolimus group (51.2% and 19.5%, respectively). Conclusion: The combination of FCO2, an excimer lamp, and PRP demonstrates superior efficacy, particularly in resistant acral areas. As a result, this combination can be recommended in difficult-to-treat areas in patients with vitiligo.

Conservation agriculture enhances crop productivity and soil carbon fractions in Indo-Gangetic Plains of India

This study evaluates the impact of conservation agriculture (CA) on soil carbon sequestration and crop productivity in the Indo-Gangetic Plains, focusing on short-term effects over 3 and 5 years. Conducted at two distinct sites, Karnal and Samastipur, the research compares zero tillage, permanent raised beds, and conventional tillage systems across diverse cropping patterns. Initial findings after 3 years showed no significant differences in carbon and nitrogen stocks at Karnal, while Samastipur’s maize-mustard-mungbean rotation on permanent raised beds showed increased carbon stocks. Notably, after 5 years, significant differences in soil carbon stocks emerged at both sites, with improved organic matter input indicated by coarse particulate organic matter (cPOM) formation. The study confirms the potential of POXC and POC as early indicators for carbon sequestration in CA systems, highlighting the role of CA practices in enhancing soil health and crop productivity sustainably.

On the use of isotopic differences of carbon fractions of biomass in plants to study transport flows and source-sink relations under different light conditions

It is shown that the differences in the isotopic composition of carbon in the water-soluble and water-insoluble fractions of plant leaf biomass, as well as phloem, are evolutionarily determined. They associated with metabolic reactions during assimilation and photorespiration and do not depend on the illumination mode and on the spectral ranges of headlights used in illumination. The above isotopic shifts are the cause of isotopic differences in assimilatory and photorespiratory carbon stocks that feed various metabolic processes. Due to the strict temporal and spatial organization of metabolism, carbon fluxes from the funds retain isotopic differences without complete mixing. The differences in the isotopic composition of carbon of the water-soluble fraction of biomass and carbon of phloem juice from carbon of the water-insoluble fraction are small (1–3%), but they are quite stable and easily fixed. The carbon of the water-soluble fraction is very close in isotopic composition to the carbon of the phloem and is noticeably enriched with the isotope 13C relative to the water-insoluble fraction, which makes it possible to use it as a marker in the study of assimilate transport in plants, especially during budding and fruiting. It is shown that the reason for the enrichment of autotrophic organs and tissues with isotope 12C relative to carbon of heterotrophic parts of the plant is the predominant participation in their formation of an isotopically light assimilation fund, whereas an isotopically heavy photorespiratory fund takes part in the formation of heterotrophic organs. It is shown that the manifestation of the formation of two isotopically different funds is the discovered relationship of the carbon isotope composition of leaves with their age.

Soil organic carbon, carbon fractions, and microbial community under various organic amendments

The impact of various organic amendments on soil organic carbon (SOC) have rarely been reported. To address this, a laboratory experiment was designed to scrutinize the effects of different amendments on soil carbon fractions, microbial communities, and the underlying interactive mechanisms. The experiment encompassed a no-amendment control (CK), as well as treatments with corn straw (CS), tobacco stalks (TS), and peanut shell biochar (PB). Over a 70-day incubation, the SOC in plots amended with CS, TS, and PB displayed significant boosts of 13.9%, 17.5%, and 44.8%, respectively, compared to the CK. For soil carbon fractions, amendments with PB, TS, and CS led to a dramatic rise in particulate organic carbon (POC) of 27.4%, 20.2%, and 105.7%, respectively, in contrast to the CK plots. Mantel analysis and structural Equation Modeling uncovered strong interrelationships among the cbbL, cbbM, Bacteroidota, TOC, and POC. Organic amendments enhance soil carbon fractions, modulating the microbial community by increasing Bacteroidetes abundance and suppressing Acidobacteria richness, thereby influencing the abundance of key carbon cycle genes such as cbbL and cbbM. These results suggest that the addition of peanut shell biochar significantly boosted TOC and key carbon fractions, enhancing carbon content and soil fertility.