Sequestration Practices Research Articles

How Can Land Use Management in Traditional Cultural Landscapes Become a Policy Instrument for Soil Organic Carbon Sequestration and Climate Change Mitigation? A Transylvanian Case Study

Changes in land use from high-nature-value grasslands to arable fields reduce the organic carbon stock in soil, increasing atmospheric carbon concentrations. Maintaining grasslands through traditional agricultural techniques can mitigate climate change by transferring atmospheric carbon to the soil. Benefits of soil organic carbon sequestration include improved soil properties and enhanced ecosystem services and biodiversity. With Romania’s ratification of the Paris Agreement, it is crucial to review climate-related agricultural policies and incentivize carbon sequestration practices in organic soils. This paper presents a soil carbon study in Transylvania’s Târnava Mare region, Romania, known for its preserved cultural landscapes. Soil samples were taken at a depth of 60 cm to assess organic carbon pools under grassland and arable land management across three soil classes: Cernisoils, Hidrisoils, and Luvisoils. Several statistical tests were applied to evaluate the most significant drivers of soil organic carbon sequestration including land use, soil class, and soil depth. The results indicate that land management has the largest impact, with grasslands storing 45% more carbon than arable land on average. This finding should be integrated into national climate action plans, prioritizing the preservation of grasslands and sustainable agricultural practices to support soil organic carbon sequestration.

Factors influencing farmers' intention to participate in the voluntary carbon market: An extended theory of planned behavior

Carbon sequestration in agricultural soils is essential for sustainable agriculture, contributing to the achievement of the Sustainable Development Goals and combating climate change. The Voluntary Carbon Market (VCM), designed to encourage farmers to implement sequestration practices, is a recent innovation in Europe, in contrast to the well-established American system. Consequently, there is limited understanding of farmers' intentions to participate. The study analyzes farmers' willingness to participate in VCM and the influencing factors through the Extended Theory of Planned Behavior (ETPB). For this purpose, data were collected from 241 Italian farmers located in the Sicily region and the partial least squares structural equation model (PLS-SEM) was applied. The results show that Attitude, Perceived Behavioral Control and Knowledge of VCM have a statistically significant influence on farmers' intention to participate in VCM. In contrast, Subjective Norms and Perceived Environmental Risk do not have a statistically significant influence. Our findings suggest that farmers' intention is strongly influenced by confidence in their capabilities and knowledge of the topic. This should guide policymakers and practitioners to offer extension services and technical assistance, helping farmers understand the potential of the VCM. Indeed, limited knowledge is a major barrier to participation in this initiative.

Unlocking the Benefits of Carbon Sequestration for Enhancing Soil Health

This abstract investigates the profound interconnection between carbon sequestration methods and soil health enhancement, crucial for sustainable land management. Evaluating various strategies, including cover cropping, reduced tillage, agroforestry, and biochar application, this study elucidates their role in augmenting soil organic carbon levels and fostering microbial diversity, thereby improving soil structure, water retention, nutrient cycling, and overall fertility. It examines the reciprocal impacts of carbon sequestration and soil health on agricultural yields, ecosystem resilience, and climate change mitigation. Furthermore, the research outlines barriers to widespread adoption, such as economic constraints and policy frameworks, emphasizing the need for interdisciplinary approaches and technological innovations. Overall, this study advocates integrating carbon sequestration practices into agricultural techniques as a pivotal step towards mitigating climate change and fortifying soil health for sustainable land use and resilient ecosystems.

Farmer’s Perception towards Mitigating Climate Change through Adoption of Soil Carbon Sequestration Practices: A Review Analysis

Climate change is one of the most severe global environmental issues. Carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases (F) are the principal greenhouse gases (GHGs) whose atmospheric concentrations are escalating. According to [1], agricultural soils have the ability to mitigate GHG emissions by 89% through the sequestration of carbon and an additional 2% and 9% through the mitigation of N2O and CH4, respectively. The process of capturing and long-term stabilisation of CO2 in the soil is known as soil carbon sequestration. Increased food production, better soil health, diversified ecosystem services, and reduced environmental footprints are all the benefits of practices increasing soil organic carbon (SOC). These techniques include planting woods, managing nutrients by using compost, sludge and green manure, and mulching [2]. Additionally, they have the ability to reduce GHG emissions by up to 8% by mitigating around 18 Mg C ha-1 C year -1 (0-15 cm soil layer). Farmers and society as a whole may benefit from this approach [3]. Supporting campaigns and initiatives to boost soil C sequestration is crucial, both on a policy level and through programmes. Additional studies needs to be done to determine the benefits of C sequestration on soil quality precisely, which encourages farmers to adopt more C-positive agricultural practices that improve productivity, as well as water and air quality [4].

Soil carbon sequestration in global working lands as a gateway for negative emission technologies.

The ongoing climate crisis merits an urgent need to devise management approaches and new technologies to reduce atmospheric greenhouse gas concentrations (GHG) in the near term. However, each year that GHG concentrations continue to rise, pressure mounts to develop and deploy atmospheric CO2 removal pathways as a complement to, and not replacement for, emissions reductions. Soil carbon sequestration (SCS) practices in working lands provide a low-tech and cost-effective means for removing CO2 from the atmosphere while also delivering co-benefits to people and ecosystems. Our model estimates suggest that, assuming additive effects, the technical potential of combined SCS practices can provide 30%-70% of the carbon removal required by the Paris Climate Agreement if applied to 25%-50% of the available global land area, respectively. Atmospheric CO2 drawdown via SCS has the potential to last decades to centuries, although more research is needed to determine the long-term viability at scale and the durability of the carbon stored. Regardless of these research needs, we argue that SCS can at least serve as a bridging technology, reducing atmospheric CO2 in the short term while energy and transportation systems adapt to a low-C economy. Soil C sequestration in working lands holds promise as a climate change mitigation tool, but the current rate of implementation remains too slow to make significant progress toward global emissions goals by 2050. Outreach and education, methodology development for C offset registries, improved access to materials and supplies, and improved research networks are needed to accelerate the rate of SCS practice implementation. Herein, we present an argument for the immediate adoption of SCS practices in working lands and recommendations for improved implementation.

Future carbon storages of ecosystem based on land use change and carbon sequestration practices in a large economic belt.

Assessments of ecosystem carbon storage are needed to form the scientific basis for carbon policies. Due to lack of data, there are few accurate, large-scale, and long-term predictions of ecosystem carbon storage. This study used the Distributed Land-Use Change Prediction(DLUCP) model with ten socioeconomic and two climate change scenarios for a total of 20 combinations that take into account population increase, technology innovation, climate change, and Grain for Green Project to make high-resolution predictions of land use change in the Yangtze River Economic Belt. Low and high carbon sequestration practices were considered to predict future carbon densities. Land use change data, carbon densities data, and the InVEST model were used to predict changes in ecosystem carbon storage from now to 2070. The results show a slight increase (1.88-4.17%) in carbon storage in the study area only based on land use change. Grain for Green Project has the largest impact on carbon storage among population increase, technology innovation, climate scenarios, and Grain for Green Project, which increases carbon storage by 4.17%. After the implementation of carbon sequestration practices, there is an increase in carbon storages from 28.51 to 56.77% in the study area from now to 2070, and increasing carbon storages of forest in each stream and carbon storage of cropland in downstream are efficient ways to achieve carbon neutralization.

Do carbon farming practices build bioavailable nitrogen pools?

AbstractAgricultural soils contain large amounts of nitrogen (N), but only a small fraction is readily available to plants. Despite several methods developed to estimate the bioavailability of N, there is no consensus on which extraction methods to use, and which N pools are critically important. In this study, we measured six soil N pools from 20 farms, which were part of a multi‐year soil carbon sequestration on‐farm experiment (Carbon action, 2019–2023). The aim was to quantify the N pools and to evaluate if farming practices that aim to build soil carbon pools, also build bioavailable N pools. We also aimed to test if the smaller and rapidly changing N pools could serve as an indicator for the slower change in soil organic matter. The measured N pools decreased in size, when moving from total N (7700 ± 1500 kg/ha) to slowly cycling (Illinois Soil Nitrogen Test ISNT‐N: 1063 ± 220 kg/ha, autoclave citrate‐extracted ACE protein N: 633 ± 440 kg/ha), water‐soluble organic N (50 ± 17 kg/ha), potentially mineralizable N (33 ± 13 kg/ha) and finally readily plant available inorganic pools (nitrate and ammonium, total: 14 ± 8 kg/ha). In total, the measured pools covered only 18%–44% of total N, indicating a large unidentified N pool, which is either tightly bound to soil mineral fraction and not easily extractable or is bound to undecomposed plant residues and not hydrolysed by the methods. Of the large N pools (ISNT‐N, ACE protein and unidentified residual N), clay, carbon (C) and C:Clay ratios explained most of the variability (R2 = .90–.93), leaving a minor part of the variation to the management effect. A pairwise comparison of carbon farming and control plots concluded that farming practices had a small (3%–5%) but statistically significant (p < .05) effect on soil total N and ISNT‐N pools, and a moderate and significant effect (18%, p < .01) on potentially mineralizable N. The large variation in protein N, water‐soluble organic N and inorganic N reduced statistical significance, although individual C sequestration practices had large effects (−30% to +50%). In conclusion, carbon sequestration practices can build both slowly cycling N pools (ISNT) and increase the mineralisation rate of these pools to release plant available forms, resulting in an additional benefit to agriculture through reduced fertilizer application needs.

The effects of continuous straw returning strategies on SOC balance upon fresh straw incorporation

Continuous straw returning is widely encouraged for augmenting soil organic carbon (SOC) in arable lands. However, the magnitude of changes in net SOC related to native SOC mineralization and new SOC development upon fresh straw incorporation remains elusive, particularly in soils after continuous straw returning with different strategies. To address this, soil that had undergone nine years of straw returning with different strategies (NS, non-straw returning; DS, direct straw returning; IS, indirect straw returning) was incubated with fresh 13C-labeled straw for 45 days. Fresh straw incorporation stimulated native SOC-derived CO2 emission in DS soil, which in turn promoted straw-derived CO2 emission in IS soil. Overall, the amounts of newly developed SOC from straw (2.41–2.59 g C/kg soil) overcompensated for the native SOC losses (0.91–1.37 g C/kg soil) by mineralization, and led to net C sequestration in all treatments. No obvious difference was found in the amounts of SOC sequestrated from straw between the DS and NS soils, while the amount of native SOC mineralization increased by 40–50% in the DS soil relative to other treatments, thus resulting in lower net C sequestration in the DS soil (1.21 g C/kg soil) than IS and NS soil (1.43 and 1.65 g C/kg for IS and NS soil, respectively). Spearman's correlation analyses indicated a significant (p < 0.01) and positive correlation between SOC contents and native soil C mineralization, while the soil microbial index played a greater role in influencing fresh straw sequestration (p < 0.01). In conclusion, the DS soil showed a weaker effect on SOC sequestration than IS after 9 years of practices, upon fresh straw incorporation. This difference may be attributed to the magnitude of native SOC mineralization in the soil. Besides the straw-C input rate, results emphasize that native soil C protection should be also considered in long-term SOC sequestration practices.

Neutron gamma analysis of soil carbon: Post-irradiation physicochemical effects

In-situ soil carbon measurements would be beneficial when assessing carbon (C) sequestration practices and associated C credits. Neutron gamma analysis, which registers gamma rays that appear due to neutron irradiation, is a tool that can be used for such assessments. However, questions regarding post-effects of neutron irradiation on soil remain unexplored. Temporal post-irradiation effects (neutron flux 2⋅107 neutron/s, neutron energy 14 MeV) on soil chemical and physical attributes were investigated using a previously constructed pulsed fast-thermal neutron-gamma analysis system. Neutron and gamma dose rate distributions during stationary irradiation using this system and Monte-Carlo computer simulations were found to be in agreement; a stationary 1 h irradiation period (conservative or worse-case scenario) was utilized in these scenarios. Physical effects of activating new radioactive isotopes were experimentally determined by assessing changes in the post-irradiated soil gamma spectra (“hot background”) over time; additional soil radioactivity decreased to natural background levels within ∼1 h. Radiolytic decomposition estimates of soil water and soil organic material (primarily cellulosic residue), based on received dose loads and known radiation-chemical yields of water and organic material, were practically negligible. Results indicate that adsorbed radiation doses in scanning mode would be 500 to 1000 times less than in static mode. Thus, neutron gamma analysis does not impact physicochemical aspects of soil health and can be used for soil elemental content determinations without additional radiation safety concerns.

Why do French winegrowers adopt soil organic carbon sequestration practices? Understanding motivations and barriers

Soil carbon sequestration (SCS) practices on French agricultural land are part of the portfolio of actions available to policymakers in the field of climate change mitigation and are central to the success of the “4 per 1,000” initiative, launched by France in 2015. To date, there has been limited research considering their applicability to vineyards. A survey was circulated to 506 French winegrowers to identify the adoption rate of six SCS practices in the viticultural sector (applying organic amendments, using biochar, returning pruning residues to the soil, no-tillage, cover cropping, and introducing or preserving hedges in the vineyard) and to explore motives and barriers to adoption. The survey also investigated ways of overcoming barriers to adoption and winegrowers' perception of agri-environment measures. Differences in motivations and barriers between SCS practices were found, and winegrowers themselves suggested a need for improved communication of evidence about SCS practices and better-targeted policy incentives to support adoption.

Mapping the distribution, trends, and drivers of soil organic carbon in China from 1982 to 2019

The evaluation of soil organic carbon (SOC) dynamics and its driving factors is important for developing sustainable soil C sequestration practices. A key challenge is the lack of a time series of spatially explicit SOC estimates; most previous SOC estimates are static. In this study, we applied a digital soil mapping framework to model the relationship between SOC and environmental factors based on a combined dataset of 4695 soil samples collected in China from the early 1980 s and during the 2000–2014 period. We predicted the annual SOC distribution at a depth of 0–100 cm at a 1 km resolution for China between 1982 and 2019. We mapped trends of SOC change and identified change hotspots. To obtain the pixel-level association between SOC change and environmental factors, we used a linear function to quantify the contribution of individual predictors to SOC change. The results show that the accuracy of SOC prediction is acceptable, with a mean R2 value of 0.58 for validation. SOC storage in China was estimated to range from 89.03 to 97.41 Pg C and showed a slight increase (slope = 0.024 Pg C/yr) from 1982 to 2019. Specifically, two distinct phases of SOC were identified as follows: (1) from 1982 to 2004, a considerable decline occurred, which was mainly driven by increased temperature; (2) from 2004 to 2019, SOC increased slowly, resulting from the contribution of greening to sustaining C sequestration in soils under warming conditions. Approximately 17 % of all areas have been characterized by a significant decrease in SOC since 1982, predominantly in central and western China. Environmental controls exhibited large spatial variation, where approximately 69 % of all areas were predominantly controlled by climate factors. For grasslands, the SOC losses in northern China were largely driven by temperature and precipitation, while the SOC losses were primarily attributed to decreased organic inputs driven by grassland degradation on the Tibetan Plateau. Policy-driven land use change has led to an increase in SOC in some cropland areas (e.g., northeast and east China). The implementation of ecological restoration has shown a positive influence on SOC sequestration. This study highlights the diverse spatial patterns and heterogeneity of SOC changes and their controls. Given this spatial differentiation, spatially explicit assessments of soil C dynamics are important for the formulation of regional soil-based mitigation strategies and guidance for effective restoration interventions based on geographic location.

A novel methodology for measurement of the diffusion coefficient between CO2 and oil based on quantification of the oil droplet swelling behavior

Accurate and fast determination of the diffusion coefficient of the CO2/oil system is essential in CO2 enhanced oil recovery (CO2-EOR) and CO2 geological sequestration practices. In this work, a novel methodology is proposed and demonstrated on measuring the diffusion coefficient of the immiscible CO2/oil binary systems based on quantification of the oil droplet swelling behavior. Five oil samples, including n-decane, n-dodecane, n-tetradecane, n-hexadecane and liquid paraffin, are employed as the oil phase and the diffusion coefficient for each CO2/oil system were determined. After validation of the methodology based on good agreements between the measurement and the reported results for both the pure component oil and the synthetic oil, the diffusion characteristics of the CO2/oil systems are scrutinized in the pressure range 2–10 MPa and the temperature range 26.9–82.1 ℃. The measurement results clearly show the elevated system pressure could lead to stronger diffusion processes between the CO2 and the oil phase, while the temperature impacts on the diffusion process are more complex due to the synergistic effects of CO2 density and the oil viscosity. Performed in the state-of-the-art drop shape analyzer within a short measurement period, it is expected the proposed methodology could provide an efficient supplementary for diffusion coefficient measurements of the CO2/oil binary systems.

Roadmap for achieving net-zero emissions in global food systems by 2050

Food systems (FSs) emit ~ 20 GtCO2e/y (~ 35% of global greenhouse gas emissions). This level tends to raise given the expected increases in food demands, which may threaten global climate targets. Through a rapid assessment, evaluating 60+ scenarios based on existing low-emission and carbon sequestration practices, we estimate that intensifying FSs could reduce its emissions from 21.4 to − 2.0 GtCO2e/y and address increasing food demands without relying on carbon offsets (e.g., related to afforestation and reforestation programs). However, given historical trends and regional contexts, a more diverse portfolio of practices, including diet shifts and new-horizon technologies, will be needed to increase the feasibility of achieving net-zero FSs. One likely pathway consists of implementing practices that shift food production to the 30th-percentile of least emission-intensive FSs (~ 45% emissions reduction), sequester carbon at 50% of its potential (~ 5 GtCO2e/y) and adopt diet shifts and new-horizon technologies (~ 6 GtCO2e/y). For a successful transition to happen, the global FSs would, in the next decade (2020s), need to implement cost-effective mitigation practices and technologies, supported by improvements in countries’ governance and technical assistance, innovative financial mechanisms and research focused on making affordable technologies in the following two decades (2030–2050). This work provides options and a vision to guide global FSs to achieving net-zero by 2050.

Soil carbon sequestration as a climate strategy: what do farmers think?

Countries and companies with net-zero emissions targets are considering carbon removal strategies to compensate for remaining greenhouse gas emissions. Soil carbon sequestration is one such carbon removal strategy, and policy and corporate interest is growing in figuring out how to motivate farmers to sequester more carbon. But how do farmers in various cultural and geographic contexts view soil carbon sequestration as a climate mitigation or carbon removal strategy? This article systematically reviews the empirical social science literature on farmer adoption of soil carbon sequestration practices and participation in carbon markets or programs. The article finds thirty-seven studies over the past decade that involve empirical research with soil carbon sequestering practices in a climate context, with just over a quarter of those focusing on the Global South. A central finding is co-benefits are a strong motivator for adoption, especially given minimal carbon policies and low carbon prices. Other themes in the literature include educational and cultural barriers to adoption, the difference between developing and developed world contexts, and policy preferences among farmers for soil carbon sequestration incentives. However, we argue that given the rising profile of technical potentials and carbon credits, this peer-reviewed literature on the social aspects of scaling soil carbon sequestration is quite limited. We discuss why the social science literature is so small, and what this research gap means for efforts to achieve higher levels of soil carbon sequestration. We conclude with a ten-point social science research agenda for social science on soil carbon—and some cautions about centering carbon too strongly in research and policy.

Assessment of changes in soil organic carbon fractions and enzyme activities under apple growing ecosystems in temperate North-Western Himalayas

For better understanding about the dynamics of soil organic carbon (SOC) and enzyme activities in soil health management under intense cropping and fluctuating climatic scenario, we examined quantitatively the spatial distribution and relationship pattern of SOC (potassium dichromate oxidizable C (KCr2O7 -C), total organic carbon (TOC or SOC stocks) and SOC pools of labile organic carbon (LBC), particulate organic carbon (POC) and microbial biomass carbon (MBC) as well as enzyme activities viz:- dehydrogenase (DHA), urease (URE) and phosphatase (PPTase) under apple growing ecosystems in north western temperate Himalayas, India. Descriptive statistics, Pearson’s correlation and spatial variability analysis of SOC attributes and enzyme activities were performed. Analysis of the results show consistent decline in SOC with depth and altitude exhibiting distinct spatial variability (CV = 15.7%–44.4%); representing significantly greater proportion in orchards of higher altitude by a margin of 346% and 295% and surface layers by 32% and 68% than sub-surface layers of those mid and lower altitudes. SOC stocks ranged from 32.1 to 94.6 Mg ha−1 with significant variation (CV = 18.0%–30.9%) between soil depths. Amongst labile carbon fractions, LBC observed significantly maximum spatial variability (CV = 15.0%–27.2%) followed by MBC (CV = 7.7%–20.6%) while as POC represents least non-significant variation (CV = 7.2%–15.5%). Although LBC (0.78 to 4.90 g kg−1) accounts for significant higher fraction (490%), MBC represents substantial reduction of 36% to 71% from surface to sub-surface layers. Decrease in microbial quotient (MQ) from an average value of 4.0% (surface) to 2.7% (sub-surface) indicates distinct spatial variability (CV = 7.5%–17.8%). The stratification ratio (SR) of SOC changed significantly amongst three altitudes varying from 2.75 to 3.96. For soil enzyme activities tested, DHA, URE and PPTase observed significant decline with depth showing maximum activity loss of 504% for URE followed by 470% for PPTase and 310% for DHA. Relationship studies recorded significantly positive correlation (p =0.05 and 0.01) for TOC with SOC and POC (0.752* and 0.814**) and between SOC and POC (0.675*), although SOC was best correlated with LBC (0.834**) and MBC (0.650**). All carbon fractions showed strong positive and significant (p = 0.05 and 0.01) relation with MBC and all enzymes (DHA, URE and PPTase) exhibited similar relationship with SOC (r = 0.638*), (r = 0.725*) and (r = 0.502**). Principal component analysis (PCA) summarized the spatial variation and relationship among SOC attributes and enzyme activities. These results of soil quality signature can be used to design and implement effective management measures in terms of addition of appropriate nutrients and effective carbon sequestration practices for soil health sustainability.

Factors influencing winegrowers’ adoption of soil organic carbon sequestration practices in France

The adoption of soil organic carbon sequestration (SCS) practices on agricultural land offers the double advantage of offsetting greenhouse gas (GHG) emissions and improving soil quality. However, little is known about the drivers that might influence winegrowers to adopt these practices, whose uptake remains low on viticultural land. Better understanding these drivers will be crucial to evaluate the efficacy of current policies in the viticulture sector in promoting and incentivising soil organic carbon sequestration in vineyards. This paper identified the factors influencing the adoption of SCS practices by winegrowers in France. A survey of 400 winegrowers investigated current rates of adoption and winegrowers’ perceptions of the practices. A binary logistic model suggested that winegrower’s age, being an independent winegrower, farm size, the number of workers hired, vine’s age, being certified High Environmental Value (HVE), being certified organic, practising irrigation, receiving subsidies, and winegrower’s perceived resources, attitude towards SCS practices and confidence significantly influenced the decision to adopt the practices, though their influence differed depending on the practice. The findings provide insights for GHG mitigation planning targeting the viticulture sector

Managing Soil Organic Carbon for Mitigating Climate Change and Increasing Food Security

This Special Issue contains articles presenting advances in soil organic carbon (SOC) sequestration practices, considering their benefits, trade-offs and monitoring. The studies deal with (1) agricultural practices and climate change, (2) the effect of organic matter amendments, and (3) the development of monitoring, reporting and verification (MRV) strategies. It is concluded that region-specific approaches are required for the implementation and monitoring of SOC sequestering practices.

Predicting the abatement rates of soil organic carbon sequestration management in Western European vineyards using random forest regression

The implementation of soil organic carbon sequestration (SCS) practices on agricultural land has the potential to help to mitigate climate change at the global level. However, our understanding of the extent to which viticultural soils can contribute to this global effort remains limited. In this study, we used a random forest regression to predict the change in soil organic carbon stocks in vineyards of Western Europe under five SCS practices: organic amendments (OA), cover cropping (CC), organic amendments and no-tillage (OA+NT), no-tillage and cover cropping (NT+CC), and a combination of organic amendments, no-tillage and cover cropping (OA+NT+CC). The abatement rate of each SCS practice was modelled and mapped for six countries in Western Europe: Spain, France, Italy, Portugal, Germany and Austria. Overall, the highest abatement rate was reached under OA+NT+CC (8.29 ​Mg CO 2 -eq. ha −1 yr −1 ), whereas the lowest was observed under CC (7.03 Mg CO 2 -eq. ha −1 yr −1 ). Results showed major differences in abatement rates at the regional and national level. Despite these differences, the adoption of SCS practices was associated with a high abatement potential in the six countries and should be encouraged in the viticulture sector as a way to offset greenhouse gas emissions via soil carbon sequestration. • Soil carbon sequestration was modelled in vineyards using random forest regression. • Random forest regression provided accurate predictions. • All modelled practices were associated with high abatement rates in vineyards. • The highest abatement rate was reached in the Canary Islands under OA+NT+CC. • Vineyards can contribute to global climate change mitigation efforts.

Soil organic carbon sequestration rates in vineyard agroecosystems under different soil management practices: A meta-analysis

Abstract Vineyards are usually cultivated in soils characterised by low soil organic carbon (SOC) content and have high risks of soil erosion and degradation. Increasing SOC stocks in these cropping systems has the potential to contribute to climate change mitigation through SOC sequestration and to enhance soil quality. We conducted a meta-analysis and compared the SOC stock response ratio, the SOC stock rate of change, and the SOC sequestration rate in vineyards under different SOC sequestration (SCS) practices relative to conventional management. SCS practices included organic amendments (OA), biochar amendments (BC), returning pruning residues to the soil (PR), no-tillage (NT), cover cropping (CC), and several combinations of these practices. The average SOC sequestration rate of SCS management was 7.53 Mg CO2-eq. ha−1 yr−1 to a 30-cm soil depth. The highest SOC sequestration rate (11.06 Mg CO2-eq. ha−1 yr−1) was achieved under a combination of OA+NT and the lowest (2.82 Mg CO2-eq. ha−1 yr−1) was observed under PR treatments. Field experiments performed in particularly hot and dry bioclimatic zones were associated with lower SOC sequestration rates relative to those performed in more temperate areas. The high SOC sequestration rates obtained for many SCS practices, and the large land area dedicated to viticulture worldwide (7.45 Mha), imply that the adoption of SCS practices in vineyards can contribute to the global efforts to offset atmospheric greenhouse gas concentrations via SOC sequestration to mitigate climate change.

Geomechanical characterization of CO2 storage sites: A case study from a nearly depleted gas field in the Bredasdorp Basin, South Africa

Geomechanical analysis and integrity assessment of hydrocarbon reservoirs upon depletion and injection are crucial to ensure that CO2 storage projects can be safely implemented. The Bredasdorp basin in South Africa has a great potential for CO2 storage given its hugely available exploration data. However, there has not been any geomechanical characterization carried out on this basin to determine its integrity issues. The aim of this study is to provide a guideline as to how geomechanical analysis of depleted fields can be done for a safe CO2 sequestration practice. The results obtained from the geomechanical model constructed for the depth of 2570 m indicated that the magnitude of the principal vertical, minimum and maximum horizontal stresses in the field are respectively 57 MPa, 41 MPa and 42–46 MPa, indicating the presence of a normal faulting regime in the caprock and the reservoir. However, according to the pore pressure-stress coupling assessment, this normal faulting is much severe in compartment C3 of the reservoir. Fault reactivation and fracture stability were also investigated after depletion and it was found that faults in the compartments C1 and C2 are stable after depletion. However, normal faults (FNS8 and FNS9) in compartment C3 dipping SW were critically stressed and may be reactivated without a proper injection planning. Fractures in compartment C3 were also critically stressed, highlighting a great potential of leakage from this compartment upon injection. It was also revealed that the sustainable maximum fluid pressure of 25 MPa would not induce any fractures in the reservoir during CO2 storage.