Carbon Content Research Articles

Experimental Study on the Ignition Behavior of Wildland Fuels Ignited by Heated Stainless-Steel Particles

ABSTRACT Hot metal particles from activities like machining, grinding, and welding are significant ignition sources for wildland fuels. Thus, this study examines the effects of stainless-steel particle geometries and wildland fuel beds on wildfire ignition behavior. To this purpose, experiments have been conducted to investigate the impact of particle type, composition, diameter, number, and wildland fuel bed species on ignition behavior. Three common California wildland grass fuel species were studied: Bromus (Bromus diandrus), Tall Wheatgrass (Thinopyrum ponticum), and Avena Wildoats (Avena fatua). Various stainless-steel grades were tested as ignition particles. The findings from this study support prior research and indicate that increasing the quantity and diameter of ignition particles reduces ignition temperature and affects the type of ignition (flaming, smoldering, or none). Moreover, results from this study showed that decreasing the carbon content in stainless steel may lower the temperature required to reach wildland fuel ignition. In addition, wildland fuel species influenced ignition type and temperature. For instance, Bromus fuels had the lowest flaming ignition temperature at 320°C whereas Tall Wheatgrass and Avena ignited at 400°C and 380°C, respectively. Flaming ignition was primarily observed in Bromus fuels, while Avena and Tall Wheatgrass primarily supported smoldering ignition. This work asserts that species-specific fuel morphology, chemical, and thermal properties affect the flammability of grassy fuels when these are ignited by metal particles and observes that in addition to particle geometry, the chemical properties of ignition particles, such as carbon content, may also lay a key role in shapping ignition behavior.

Unravelling the thermodynamic properties of soil ecosystems in mature beech forests

Thermodynamics is a vast area of knowledge with a debatable role in explaining the evolution of ecosystems. In the case of soil ecosystems, this role is still unclear due to difficulties in determining the thermodynamic functions that are involved in the survival and evolution of soils as living systems. The existing knowledge is largely based on theoretical approaches and has never been applied to soils using thermodynamic functions that have been experimentally determined. In this study, we present a method for the complete experimental thermodynamic characterization of soil organic matter. This method quantifies all the thermodynamic functions for combustion and formation reactions which are involved in the thermodynamic principles governing the evolution of the universe. We applied them to track the progress of soil organic matter with soil depth in mature beech forests. Our results show that soil organic matter evolves to a higher degree of reduction as it is mineralized, yielding products with lower carbon but higher energy content than the original organic matter used as reference. These products have higher entropy than the original one, demonstrating how the soil ecosystem evolves with depth, in accordance with the second law of thermodynamics. The results were sensitive to soil organic matter transformation in forests under different management, indicating potential applicability in elucidating the energy strategies for evolution and survival of soil systems as well as in settling their evolutionary states.

Improvement of microbial alkalinity resistance in self-healing cementitious materials by means of gradient domestication

The harsh environment of high alkalinity inhibits the effective induction of calcium carbonate precipitation by microorganisms within concrete. In this study, a gradient domestication method was employed to enhance the alkali tolerance of Sporosarcina pasteurii, and various activity parameters (OD600, conductivity, urease activity, and calcium carbonate content) were assessed in an alkaline cultivation setting. Subsequently, a comprehensive evaluation was conducted to compare the impact of domesticated microorganisms on the mechanical properties, impermeability, and self-healing capacity of concrete. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were employed to characterize the morphology and composition of mineralization products. The results demonstrate that gradient domestication techniques effectively enhance the activity of microorganisms in highly alkaline environments and confirmed that enhanced alkalinity tolerance possesses the potential for multigenerational retention. In comparison to the undomesticated microbial samples at 28 d, concrete incorporating domesticated microorganisms exhibited a 16.59 % increase in compressive strength, a 37.74 % reduction in sorption, and a 23.08 % decrease in permeability. Additionally, the maximum closed crack width measured 0.57 mm, exceeding the 0.44 mm observed in the non-domesticated bacterial group. This study offers a promising strategy for improving the efficiency of microbial-induced calcium carbonate precipitation in concrete.

Long-term Application of Agricultural Amendments Regulate Hydroxyl Radicals Production during Oxygenation of Paddy Soils.

Hydroxyl radicals (•OH) play a significant role in contaminant transformation and element cycling during redox fluctuations in paddy soil. However, these important processes might be affected by widely used agricultural amendments, such as urea, pig manure, and biochar, which have rarely been explored, especially regarding their impact on soil aggregates and associated biogeochemical processes. Herein, based on five years of fertilization experiments in the field, we found that agricultural amendments, especially coapplication of fertilizers and biochar, significantly increased soil organic carbon contents and the abundances of iron (Fe)-reducing bacteria. They also substantially altered the fraction of soil aggregates, which consequently enhanced the electron-donating capacity and the formation of active Fe(II) species (i.e., 0.5 M HCl-Fe(II)) in soil aggregates (0-2 mm), especially in small aggregates (0-3 μm). The highest contents of active Fe(II) species in small aggregates were mainly responsible for the highest •OH production (increased by 1.7-2.4-fold) and naphthalene attenuation in paddy soil with coapplication of fertilizers and biochar. Overall, this study offers new insights into the effects of agricultural amendments on regulating •OH formation in paddy soil and proposes feasible strategies for soil remediation in agricultural fields, especially in soils with frequent occurrences of redox fluctuations.

Level of thermal maturity estimation in unconventional reservoirs using interval inversion and simulating annealing method

AbstractThis study presents a novel geophysical approach for estimating the level of thermal maturity (LOM) in unconventional hydrocarbon reservoirs using well log data. LOM is a crucial parameter for assessing the hydrocarbon generation potential of source rocks, but it traditionally relies on laboratory measurements of core samples, which can be time-consuming and costly. The proposed method combines two techniques: interval inversion for estimating total organic carbon (TOC) content from well logs and simulated annealing (SA) optimization for deriving LOM from the estimated TOC. The interval inversion method enables accurate TOC estimation by jointly interpreting multiple well logs over depth intervals, overcoming limitations of conventional point-by-point inversion. Using the estimated TOC, the SA algorithm optimizes an energy function related to Passey's empirical TOC-LOM relationship, iteratively finding the optimal LOM value that best fits the well log data. This approach provides a continuous in situ LOM profile along the borehole without requiring core measurements. The effectiveness of the method is demonstrated through case studies on datasets from the North Sea (Norway), the Pannonian Basin (Hungary), and the Kingak Formation (Alaska). The LOM estimates show good agreement with reported maturity levels and allow reliable reservoir characterization. Statistical analysis confirms the robustness and accuracy of the results. By reducing dependence on core data, this integrated inversion-optimization workflow streamlines the reservoir prospecting phase, enhancing operational efficiency. The method holds promising applications across diverse geological settings for cost-effective evaluation of unconventional hydrocarbon plays.

The impact of insect herbivory on biogeochemical cycling in broadleaved forests varies with temperature

Herbivorous insects alter biogeochemical cycling within forests, but the magnitude of these impacts, their global variation, and drivers of this variation remain poorly understood. To address this knowledge gap and help improve biogeochemical models, we established a global network of 74 plots within 40 mature, undisturbed broadleaved forests. We analyzed freshly senesced and green leaves for carbon, nitrogen, phosphorus and silica concentrations, foliar production and herbivory, and stand-level nutrient fluxes. We show more nutrient release by insect herbivores at non-outbreak levels in tropical forests than temperate and boreal forests, that these fluxes increase strongly with mean annual temperature, and that they exceed atmospheric deposition inputs in some localities. Thus, background levels of insect herbivory are sufficiently large to both alter ecosystem element cycling and influence terrestrial carbon cycling. Further, climate can affect interactions between natural populations of plants and herbivores with important consequences for global biogeochemical cycles across broadleaved forests.

A systematic benchmarking framework for future assessments of soil health: An example from Denmark

Based on current evidence and established critical thresholds for soil degradation indicators, it is concerning that over 60–70% of European soils are unhealthy due to unsustainable management and the impact of climate change. Despite European and national efforts to improve soil health, significant gaps remain. The proposal for a Soil Monitoring and Resilience Law, to be implemented by the European Union, seeks to establish a framework for soil monitoring and promote sustainable management practices to achieve healthy soils by 2050. This requires extensive data collection and soil monitoring systems to accurately estimate soil health across Europe, considering the diversity of soil types, climates, and land uses. To establish a framework for soil monitoring, we must understand the site-specific status of soil and the ranges of soil health indicators across specific pedoclimatic regions. In our study, we evaluated the soil status in agricultural areas in Denmark using soil health indicators and a site-specific benchmarking approach. We compiled nationally representative datasets, combining point and model-informed data of soil parameters such as organic carbon content, bulk density, pH, electrical conductivity, clay-to-soil organiccarbon ratio, water erosion, and nitrogen leaching. By categorizing Danish agricultural soils into monitoring units based on textural classes, landscape elements, and wetland types, we calculated benchmarks for these indicators, considering different cropping systems. Our approach provided detailed point-based results and a spatially explicit overview of the status of soil health indicators in Denmark. We identified areas where soil deviates from the benchmarks of different indicators. Such deviations might indicate soil functions operating outside the normal range, posing potential threats to soil health. This proposed framework could support the establishment of a baseline for assessing the directionality of future changes in soil health. Moreover, it is adaptable for implementation by other countries to support assessments of soil health.

MSA-Net: A Precise and Robust Model for Predicting the Carbon Content on an As-Received Basis of Coal.

The carbon content as received (Car) of coal is essential for the emission factor method in IPCC methodology. The traditional carbon measurement mechanism relies on detection equipment, resulting in significant detection costs. To reduce detection costs and provide precise predictions of Cars even in the absence of measurements, this paper proposes a neural network combining MLP with an attention mechanism (MSA-Net). In this model, the Attention Module is proposed to extract important and potential features. The Skip-Connections are utilized for feature reuse. The Huber loss is used to reduce the error between predicted Car values and actual values. The experimental results show that when the input includes eight measured parameters, the MAPE of MSA-Net is only 0.83%, which is better than the state-of-the-art Gaussian Process Regression (GPR) method. MSA-Net exhibits better predictive performance compared to MLP, RNN, LSTM, and Transformer. Moreover, this article provides two measurement solutions for thermal power enterprises to reduce detection costs.

The Effect of Wood Species on Fine Particle and Gaseous Emissions from a Modern Wood Stove

Residential wood combustion (RWC) is a significant source of gaseous and particulate emissions causing adverse health and environmental effects. Several factors affect emissions, but the effects of the fuel wood species on emissions are currently not well understood. In this study, the Nordic wood species (named BirchA, BirchB, Spruce, SpruceDry, Pine and Alder) were combusted in a modern stove, and the emissions were studied. The lowest emissions were obtained from the combustion of BirchA and the highest from Spruce and Alder. The fine particle mass (PM2.5) was mainly composed of elemental carbon (50–70% of PM2.5), which is typical in modern appliances. The lowest PAH concentrations were measured from BirchA (total PAH 107 µg/m3) and Pine (250 µg/m3). In the ignition batch, the PAH concentration was about 4-fold (416 µg/m3). The PAHs did not correlate with other organic compounds, and thus, volatile organic compounds (VOCs) or organic carbon (OC) concentrations cannot be used as an indicator of PAH emissions. Two birch species from different origins with a similar chemical composition but different density produced partially different emission profiles. This study indicates that emission differences may be due more to the physical properties of the wood and the combustion conditions than to the wood species themselves.

Optimization of fertilizer use efficiency, soil quality and oil palm (Elaeis guineensis Jacq.) growth with biochar under drip irrigation conditions irrigation conditions

Biochar (BC) is an eco-friendly product characterized with high content of carbon and usually obtained by heating biomass without oxygen. Utilizing BC as organic material to amend the problematic soils and improve plant growth and yield has been proved previously. This study investigated the effect of vetiver grass biochar (VGB) on fertilizer use efficiency, soil quality, and oil palm growth performance. A net house experiment was conducted at the Farm Unit, UiTM Sarawak Branch, between August 2022 and March 2023. A factorial randomized complete block design (RCBD) with five treatments and four replications was devised. Treatments applied were: T0) absolute control; T1) 100% NPK fertilizer; T2) 100% vetiver grass biochar; T3) 50% vetiver grass biochar + 50% NPK fertilizer; and T4) 25% vetiver grass biochar + 75% NPK fertilizer. The BC application significantly improved the fertilizer use efficiency through reducing the rate of fertilizer applied. It also significantly enhanced most soil-measured chemical properties and soil nutrients. The growth performance of oil palm plant was significantly enhanced by BC application in terms of plant height, hump diameter, leaf number, chlorophyll content, and plant biomass. The BC application demonstrated its usefulness in managing soil and cultivating oil palm plant sustainably by reducing the rate of fertilizer applied and improve the fertilizer use efficiency. Based on the output, we suggest that treatment T3 (50% vetiver grass biochar + 50% NPK) can be used to improve the growth performance of oil palm.

Effect of Different Levels of NPK, Biochar and Azotobacter on Physico-chemical Properties of Soil on Cowpea (Vigna unguiculata)

In light of this, the following goals are present in the experiment "Effect of Different Levels of NPK and Biochar, Azotobacter on Physico-chemical Properties of Soil and Yield Attributes of Cowpea to calculate the impact of various NPK, Biochar, and Azotobacter dosages on the physical-chemical characteristics of soil. An excavated soil sample from the experimental site revealed that the land topography ranged from nearly level to sloped by 1% to 6%, with soil area falling into the Inceptisol order. The soil texture was sandy loam, with sand percentages of 62.65%, silt percentages of 21.09, and clay percentages of 16.26. The pH of soil was 6.89, and its electrical conductivity (EC) was non-saline (0.42 ds m-1). Organic carbon content was low to medium, available nitrogen was low to medium (280.78 kg ha-1), available phosphorus was 17.34 kg ha-1, and available potassium was 168.16 kg ha-1. Two factors with three levels of @NPK 0, 50, and 100% ha-1, three levels of @Biochar 0, 50, and 100% ha-1, and a randomized block design were used in the statistical analysis. During field testing, nine different treatments were used; the best outcomes were significant. The results indicate that the physical and chemical parameters of the soil, including the cumulative mean values for bulk density (1.39 and 1.41 mg m-3), particle density (2.46 and 2.47 mg m-3), and soil pH (6.89 and 6.91), attained their maximum in T1 (Absolute control) at depths of 0-15 cm and 15-30 cm, respectively. Additionally, the percentage pore space was found to be 48.22% and 47.39%, and the water holding capacity was found to be 44.14% and 45.34%), electrical conductivity (EC) was measured at 0.49 ds m-1 and 0.52 ds m-1, the percentage of organic carbon was determined to be 0.40%), and the available nitrogen was found to be (299.78 kg ha-1 and 295.76 kg ha-1, available phosphorus was (23.78 kg ha-1 and 21.98 kg ha-1), and the available potassium was (179.25 kg ha-1 and 176.56 kg ha-1).

Recycling Agricultural Waste to Enhance Sustainable Greenhouse Agriculture: Analyzing the Cost-Effectiveness and Agronomic Benefits of Bokashi and Biochar Byproducts as Soil Amendments in Citrus Nursery Production

Applying bokashi (Bok) at 10% volume/volume (v/v), biochar (BC) at 10% v/v, and their combination (Bok_BC) as soil amendments significantly enhances citrus nursery production, improving plant growth and soil health, alongside offering notable economic benefits. Our greenhouse experiment evaluated these treatments across two fertilizer doses, at half (700 μS/cm) and full (1400 μS/cm) electrical conductivity (EC) levels, compared to a control mix, demonstrating improved nutrient availability, water retention, growth rates, and potential for carbon sequestration. Based on the results of this experiment, a cost–benefit analysis was performed; the BC treatment yielded substantial savings, particularly in large nurseries where BC at 700 μS/cm electrical conductivity (EC) saved USD 1356.38 per day and the same treatment at 1400 μS/cm EC saved USD 1857.53. These savings stem from increased nutrient contents (N, P, and K) and improved water retention, reducing irrigation; shortened growth cycles due to enhanced growth rates were observed, indirectly suggesting reduced electricity costs for greenhouse operations. Additionally, the increased carbon content within the soil points toward long-term benefits from carbon sequestration, further contributing to the sustainability and economic viability of these practices. These findings highlight the economic advantage of incorporating Bok and BC into soil mixes, providing a cost-effective strategy for enhancing greenhouse agriculture sustainability.

Aspergillus niger as an efficient biological agent for separator sludge remediation: two-level factorial design for optimal fermentation.

The booming palm oil industry is in line with the growing population worldwide and surge in demand. This leads to a massive generation of palm oil mill effluent (POME). POME is composed of sterilizer condensate (SC), separator sludge (SS), and hydro-cyclone wastewater (HCW). Comparatively, SS exhibits the highest organic content, resulting in various environmental impacts. However, past studies mainly focused on treating the final effluent. Therefore, this pioneering research investigated the optimization of pollutant removal in SS via different aspects of bioremediation, including experimental conditions, treatment efficiencies, mechanisms, and degradation pathways. A two-level factorial design was employed to optimize the removal of chemical oxygen demand (COD) and turbidity using Aspergillus niger. Bioremediation of SS was performed through submerged fermentation (SmF) under several independent variables, including temperature (20-40°C), agitation speed (100-200 RPM), fermentation duration (72-240 h), and initial sample concentration (20-100%). The characteristics of the treated SS were then compared to that of raw sludge. Optimal COD and turbidity removal were achieved at 37°C 100 RPM, 156 h, and 100% sludge. The analysis of variance (ANOVA) revealed a significant effect of selective individual and interacting variables (p<0.05). The highest COD and turbidity removal were 97.43% and 95.11%, respectively, with less than 5% error from the predicted values. Remarkably, the selected optimized conditions also reduced other polluting attributes, namely, biological oxygen demand (BOD), oil and grease (OG), color, and carbon content. In short, this study demonstrated the effectiveness of A.niger in treating SS through the application of a two-level factorial design.

Assessment of the Influence of zaï, Stone Rows, and Organo-mineral Fertiliser on Soil Properties and Groundnut Yields Performances in Sudan Sahelian Zone of Burkina Faso

Groundnut occupies a vital position in oilseed crop production in Burkina Faso, with current production at 630,526 tonnes. However, its production faces threats from drought and low soil fertility. This study aims to determine the influence of zaï, stone rows, ridge tillage, and mineral fertilisation on soil health and on groundnut yields performances in Sudan Sahelian zone of Burkina Faso. Experimental treatments were distributed randomly following a Fisher block design, comprising four treatments and five replications, in the village of Sandogo. Data on soil properties, plant growth, and yields were analysed using variance analysis in R software. The results indicate significant influences of the treatments on carbon content, nitrogen content, phosphorus content, pH values, soil moisture content, soil carbon dioxide release, and soil macrofauna. Moreover, notable effects were observed on the number of nodules, drier nodule weight, number of leaves and branches, pod load, pod and straw yields, and the weight of 100-pods. The highest carbon content (0.857; 0.861%), nitrogen content (0.081%; 0.087%), phosphorus content (7.488; 7.735 mg.kg-1), pH values (6.43; 6.54), and soil moisture content (24.80; 25.27%) were recorded in the homogeneous group of zaï and zaï associated to stone rows. The highest carbon dioxide release (2863.33 ppm) was recorded in plots treated with stone rows. Ants were the most widely encountered macrofauna, whereas no earthworms were recorded. The highest performance in terms of the number of nodules (84.76; 87.88), dry nodule weight (0.0893; 0.0886 g/plant), number of leaves (40; 40), number of branches (6; 6), pod load (25; 25), weight of 100-pods (112.90; 111.98 g), straw yields (1673.28; 1664.87 kg.ha-1), and pod yields (2122.32; 2161.96 kg.ha-1) were achieved with zaï and zaï combined with stone rows. Zaï and zaï combined with stone rows can therefore be used as effective alternatives to improve groundnut production in the Sudan Sahelian zone of Burkina Faso in a context of climate change, while protecting the environment.

Effects of Land Use Change on Soil Aggregate Stability and Erodibility in the Karst Region of Southwest China

Differences in land use type and chronological age affect soil properties and plant community characteristics, which may influence soil structural stability and erodibility. However, knowledge on the effects of soil physicochemical properties on soil aggregate stability and erodibility at different land use years is limited. This study selected five land use types: corn field (Year 38th-y), corn intercropped with cabbage field (Year 38th-y + b), fruit and meridian forest (Year 6th-jgl), naturally restored vegetation (Year 6th-zr), and artificial forest (Year 7th-rgl) in the karst landscape of the Chishui River Basin in Yunnan Province. We aimed to identify the influencing factors of soil stability and erodibility under different land use time series. The results indicated that the mean weight diameter (MWD), the geometric mean diameter (GMD), and soil structural stability index (SSI values) were highest in Y6th-zr and lowest in Y7th-rgl. Conversely, the erodibility K value was lowest in Y6th-zr, suggesting that the soil structure in Y6th-zr exhibited greater stability, whereas soil stability in Y7th-rgl was lower. Redundancy and throughput analyses revealed that organic carbon and water-stable aggregates &gt; 2.0 mm content had higher vector values. Soil bulk density, total nitrogen, organic carbon, and soil texture content were the main factors contributing to soil stability variation (0.338–0.646). Additionally, total nitrogen, organic carbon, total phosphorus, and soil texture content drove the variation in K values (0.15–1.311). Natural vegetation restoration measures can enhance soil structure to a certain extent. These findings highlight changes in soil aggregate stability and erodibility over different land use durations. The research results have important theoretical and practical significance for understanding the differences in soil erosion and soil restoration under different land use patterns in the karst landscapes of southwest China.

Deficit Irrigation as an Effective Way to Increase Potato Water Use Efficiency in Northern China: A Meta-Analysis

Water scarcity poses a significant threat to the sustainable production of crops in Northern China. Despite this, the effect of water management practices, such as deficit irrigation, on the yield and WUE of potatoes has been rarely explored. Based on the meta-analysis of field experiment data, this study evaluated the influence of deficit irrigation on potato yield, evapotranspiration (ET), water use efficiency (WUE) and irrigation water use efficiency (IWUE) under variable soil types, water-saving ratio, irrigation methods, soil organic carbon (SOC) content, and fertilizer rate in Northern China. Here, we determined that potato WUE and IWUE were significantly increased by 10.0 and 31.6%, respectively, under deficit irrigation, while ET was significantly decreased by 26.3% compared to full irrigation. Conclusively, deficit irrigation significantly reduced potato yields by 16.4% compared to full irrigation. Furthermore, SOC content played a vital role in improving the WUE and alleviating potato yield losses under deficit irrigation. Our study suggested that maximum WUE with lower potato yield losses under deficit irrigation can be achieved in the Central Plains region of China or in yellow loam soil, brown soil, and meadow soil under alternate root-zone irrigation when the water-saving ratio was less than 45% and fertilizer application rates were 300 kg N ha−1, &gt;240 kg P2O5 ha−1, and 181–300 kg K2O ha−1. Overall, these findings highlight the need for a comprehensive understanding of various agricultural management practices and local environmental conditions to optimize the benefits of deficit irrigation in potato-growing regions across Northern China.

Response of tomato to innovative organo-mineral fertilizers

Organo-mineral fertilizers (OMFs) with low organic carbon (Corg) content have been associated with higher mineral fraction nutrient use efficiency. However, the extraction of peat, which is typically used in these OMFs, from endangered ecosystems causes long-time stored Corg to mineralize and to be released back into the atmosphere as carbon dioxide (CO2). This study analyzes the replacement of peat in OMFs with biowaste materials. These materials, considered organic byproducts that microorganisms and other living things can decompose through composting and aerobic or anaerobic digestion, offer a viable opportunity. This study investigated three stabilized biowastes—green compost (GC) from pruning residues, municipal solid waste compost (MSWC), and manure-based vermicompost (VC)—as the organic matrices for granular OMFs. These matrices were impregnated with dissolved ammonium sulfate and urea and used to coat diammonium phosphate granules. Each biowaste OMF contained 7.5% Corg, 20% mineral N, and 10% mineral P2O5 (OMF20 − 10). Fertilizers with high nutrient concentrations have the advantage of requiring low application volumes, facilitating their application in the field. Biowaste OMFs were compared with peat OMFs with the same Corg-N-P2O5 concentration. Peat and MSWC were also used to create OMFs containing 7.5% Corg, 10% mineral N, and 5% mineral P2O5 (OMF10 − 5). A 75-day tunnel trial was conducted under semi-controlled conditions using tomato plants (Solanum lycopersicum L.) fertilized to an equivalent of 81 mg N kg−1 soil and 18 mg P kg−1 soil. Controls included no fertilization (N0P0) and mineral N and P fertilization (MFNP). The Soil Plant Analysis Development (SPAD) chlorophyll meter and the BBCH (from German Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) scale as well as the number of shoots were measured over time, as berry and total aboveground yield, N and P uptakes, and N and P use efficiencies (NUE and PUE, respectively) were calculated at harvest. All treatments outperformed the control N0P0 in most indicators. Peat20 − 10 did not have more berry yield than other OMF20 − 10; however, the higher number of shoots indicated a higher potential yield in the event of prolonging the experiment. At the end of 75 days, VC20 − 10 and MSWC20 − 10 showed similar PUE to peat, suggesting that those materials can be used as replacements. In the case of OMF10 − 5, MSWC10 − 5 had yield and N and P uptakes like peat OMFs, confirming the potential use of MSWC as peat replacement even at different nutrient concentrations. This research provides reassuring evidence of the effectiveness of biowaste OMFs, offering a positive outlook for sustainable agriculture. However, their use is not recommendable for short growing seasons.

Carbon evolution and mixing effects on groundwater age calculations in fractured basalt, southwestern Idaho, U.S.A.

Using hydrochemical and isotopic compositions of springs and wells, we trace carbon from critical zone carbon dioxide (CO2) into groundwater of the semi-arid Reynolds Creek Experimental Watershed - Critical Zone Observatory, southwestern Idaho, USA. Dissolved inorganic carbon (DIC) concentrations, pH and stable isotope tracers of carbon for DIC (δ13CDIC), are used to show that most groundwater evolves under open system conditions, moving carbon into the groundwater and acting as a carbon sink. However, one sample (−10.94‰ δ13CDIC, 6,350 14C years before present (yrs. BP)) may have evolved under closed system conditions with a higher partial pressure of critical zone CO2 than present-day soils. By characterizing the carbon cycle, we show that (1) carbon evolution is primarily under open-system conditions, (2) shallow groundwater samples are generally less mixed and more recent (10 to 70 3H yrs. BP) than deeper groundwater samples (1,469 to 6,350 14C yrs. BP), and (3) the older portion of the groundwater may be even older than the calculated 14C ages, as indicated by the mixing of age tracers in intermediate wells. Our global conception of the deep critical zone should include carbon cycling of critical zone CO2 in old groundwater. Characterizing the deep critical zone in a semi-arid weathered silicate watershed improves our global understanding of carbon, nutrient and water cycling.

Influence of varying aluminum-based combustion compartment sizes on groundnut shell biochar properties

The process variables during biochar production play a crucial role in determining its properties. Factors like temperature, heating rate, reactor configuration, and residence time can significantly impact biochar quality. The aim of this study is to determine the impact of reactor configuration on the yield and properties of groundnut shell biochar. For this investigation, the volumes of aluminum-based combustion compartments in a biomass-fueled TLUD biomass gasifier were varied, and the resulting biochar was analyzed using SEM, EDX, and FTIR. It was observed that the increase in the combustion chamber of the gasifier led to an increase in the amount of biomass fuel utilized in the system, which led to an increased reactor’s temperature and varied carbonization duration and yield. Elemental composition showed that an increase in reactor volume led to an increase in biochar carbon content and reduced silica content. The SEM analysis confirmed that decreasing the combustion compartment sizes increased porosity and roughness, as well as visible fissures and crevices on the biochar surface. FTIR analysis revealed similarities in functional groups, with many peaks appearing at higher wavenumbers as the combustion compartment sizes decreased. This study innovatively examines how varying aluminum-based combustion compartment sizes and biofuel mass affect groundnut shell biochar properties using a TLUD gasifier, emphasizing its significance for optimizing biochar production and advancing sustainable practices.

Multilayer Diamond‐Like Carbon Films on Monocrystalline Diamond

Multilayer films of diamond‐like carbon (DLC) on monocrystalline diamond substrates have been for the first time obtained by plasma‐chemical deposition. Their chemical composition and structural and morphological properties are studied. The DLC individual layers differ in their sp3 carbon content. The multilayer nature of the resulting coatings is confirmed by periodic density modulation on the small‐angle X‐ray reflectometry curve and modulations in the CsC8, CsC6, CsC4 lines on the crater depth profile of secondary ions of elements (secondary ion mass spectrometry). The dependence of the deposition rate of multilayer DLC films on diamond, their composition and properties on the argon additive to the reaction gas mixture, as well as on methane flow, pressure and growth time, are studied.