Enhance Soil Carbon Sequestration Research Articles

Integrating green manure and fertilizer reduction strategies to enhance soil carbon sequestration and crop yield: evidence from a two-season pot experiment

The excessive use of chemical fertilizers in agricultural production has led to diminishing returns, necessitating alternative methods to enhance soil fertility and reduce fertilizer dependency. One promising approach is the integration of leguminous green manure, which improves soil structure, enhances nutrient cycling, and supports sustainable farming practices. However, the application of green manure in systems with continuous fertilizer reduction remains underexplored. This study addresses this gap by investigating the effects of reducing nitrogen and phosphorus fertilizers (N-P) by up to 24% in conjunction with multiple cropping of soybean green manure on soil fertility, organic carbon fractions, and wheat yield. The research employed a pot experiment conducted over two wheat-growing seasons (March 2021 to July 2022) at an experimental station in Baoji, China. Treatments included CK (control, no fertilizer), CF (conventional fertilizer), and reduced N-P fertilizer applications by 6% (RF6), 12% (RF12), 18% (RF18), and 24% (RF24). Key findings revealed that RF12 had no significant impact on wheat grain yield compared to CF. The incorporation of soybean green manure significantly improved soil alkaline nitrogen by 22.3% and available phosphorus by 30.7%, while high-labile organic carbon (H-LOC) and microbial biomass carbon (MBC) increased by 34.5 and 29.6%, respectively. Additionally, a notable increase of 12.4% in soil organic carbon content was observed, suggesting enhanced carbon sequestration potential. This study provides valuable insights into sustainable agricultural practices by demonstrating that incorporating leguminous green manure alongside moderate fertilizer reduction can maintain crop yield, improve soil nutrient availability, and increase organic carbon content, thus supporting reduced reliance on chemical fertilizers and promoting long-term soil fertility and carbon sequestration.

Depth-Dependent Impacts of Long-Term Vegetation Restoration on Soil Carbon Stability and C/N Stoichiometry in Subtropical Plantations

Vegetation restoration has played a significant role in preventing soil erosion and enhancing soil carbon sequestration in the hilly regions of subtropical China. However, under long-term vegetation restoration, it remains unclear how soil organic carbon and nitrogen components synergistically change and whether their dynamics are consistent across different soil depths. This study investigates the soils of four major vegetation types in subtropical hilly regions: enclosed Masson pine forest (EMP), Masson pine forest (MP), slash pine forest (SP), and mixed broadleaf–conifer forest (MBC). Soil organic carbon (SOC) components, nitrogen components, and physicochemical properties were analyzed across different soil depths (0–100 cm) under these vegetation restoration types. Results showed that forest type significantly influenced SOC stability. The MBC exhibited the highest mineral-associated organic carbon (MAOC) content, indicating the highest SOC stability. Both the MBC and SP forests sequestered more iron-aluminum-bound organic carbon (FeOC) and less Ca-associated organic carbon (CaOC) compared to the other forest types. The dominance of FeOC over CaOC in these acidic soils highlights the critical role of iron-aluminum oxides in SOCSOC stabilization. Vegetation restoration significantly influenced the relationship between SOC and nitrogen components in the topsoil (0–20 cm), but this effect diminished in the subsoil (>20 cm). This study confirmed the depth-dependent impacts of long-term vegetation restoration on soil carbon stability and C/N stoichiometry in subtropical plantations. Targeted vegetation restoration strategies can improve SOC stability in subtropical plantations.

Unfolding the Roles of Particulate- and Mineral-Associated Organic Carbon in Soil Microbial Communities

Forest succession is a rapid approach that can be used to increase soil carbon (C) stocks. It is crucial to understand how forest succession influences microbial community assembly and soil carbon fractions to improve carbon sequestration strategies. This present work analyzed microbial communities in forest succession, and the effects of particulate-associated organic C (POC) and mineral-associated organic C (MAOC) on microbial community structure and assembly in forest succession in Changbai Mountains, China. Compared to cropland, primary forest increased MAOC by 35% and POC by 43%, suggesting the importance of POC for microbial assembly processes, offering insights into forest restoration practices to enhance soil carbon sequestration. As succession proceeds, weak environmental selection facilitated the reduced deterministic processes, whereas local ecological and dispersal drift were elevated. Such shifts in fungal and bacterial communities could be mostly triggered by soil pH. Considering that POC was important, shifts in assembly processes can be determined by resource availability rather than succession sequences. Such findings conform to the neutral hypothesis, suggesting that POC exerts a negligible effect on analyzing microbial community assembly in forest succession. Overall, this present work sheds more light on the important effects of POC and MAOC on modeling different microbial communities and community assembly in forest succession.

Carbon and Nitrogen Accumulation in Roots of Signal Grass–Forage Peanut Intercropped Pastures at Varying Planting Spacings

This study highlights the potential of grass–legume intercropping systems in enhancing soil carbon sequestration and cycling nutrientes, providing ecological support for sustainable agriculture. This study evaluated the chemical composition and root biomass of signal grass (Urochloa decumbens cv. Basilisk) pasture grown in monoculture or intercropped with forage peanut (Arachis pintoi cv. Belmonte) under different row spacings (40, 50, 60, 70, and 80 cm), 4–5 years after establishment. The experiment was conducted in a randomized block design with four replicates under intermittent sheep grazing. Results (p < 0.05) indicated that root biomass was higher in the intercropped pastures (6752 to 11,167 kg OM ha−1) than in the monoculture (3696 kg OM ha−1). Carbon (C) and N stored in root biomass were also influenced by the row spacings, with narrower spacings, particularly 40 cm (1282 kg C ha−1) and 50 cm (1424 kg C ha−1), showing higher C storage than in the monoculture (509 kg C ha−1). Similarly, the 40 cm (122 kg N ha−1) and 50 cm (138 kg N ha−1) spacings showed higher N accumulation in root biomass than the monoculture (38.9 kg N ha−1). These spacing also reduced C/N and lignin/ADIN ratios, which enhanced nitrogen cycling efficiency. Based on these results, 40 and 50 cm spacings are recommended for intercropped pastures, as they optimize C and N accumulation and nutrient cycling, and support sustainable pasture management.

Soil Organic Carbon in Three Selected Agroforestry System at Temperate Zone (2000-2800m) of North Western Himalaya, Uttarakhand, India

Climate change is largely driven by the increased concentration of greenhouse gases like carbon dioxide (CO₂) in the atmosphere. While halting climate change entirely may not be feasible at this point, mitigating its effects is crucial, and agroforestry is one of the key strategies that can help in this regard and to mitigate some of its consequences by reducing CO₂ in the atmosphere and promoting sustainable land management. Therefore, the objective of this study was to collate and synthesize the existing information on the soil organic carbon with three agroforestry system (viz.Agrihortisystem, Agrihortisilviculture system and Agrisilviculture system ) at temperate region in North Western Himalaya , Uttarakhand, India.The present study was carried out durung the year 2016-2018.Stratified random sampling techniques were used for this study. Ten sample plots (100m2) were randomly laid out in each agroforestry system in temperate zone (2000-2800m) of each developmental block. Soil organic carbon was determined at three different depth 0-10, 10-20 and 20-30 cm. Soil organic carbon was determined using the Walkley and Black method. Weighing bottle method were used for determining bulk density. The results revealed considerable that SOC of agroforestry systems goes along with the following order: Agrihortisystem (45.72 MgCha-1) >Agrihortisilviculture system (24.99 MgC ha-1) >Agrisilvi culture system (23.79 MgC ha-1) The study concluded that the agrihorticulture system at higher altitudes (2000-2800 m) had a significantly greater soil organic carbon pool. It was suggested that, if necessary, converting agricultural fields to agrihorticulture systems in the Northwestern Himalayas could enhance soil carbon sequestration.

Study on the carbon sequestration effect of biochar in vegetable fields

This study was conducted using a field experiment methodology aimed at assessing the effects of biochar application on tomato growth and soil properties in greenhouse greenhouses. Biochar, a carbon-rich material produced by pyrolysis of biomass under anoxic conditions, has attracted attention for its potential in soil amelioration, carbon sequestration, and soil fertility enhancement. In this experiment, three biochar application levels of 0, 20, and 40 t/ha were designed to investigate the effects of different application rates on soil chemical properties and tomato growth.The study results showed that biochar application significantly increased soil pH by 0.05 to 0.1 units, which was beneficial in regulating acidic soil. Meanwhile, biochar application significantly increased total soil carbon content by 7.5 to 28.8%, indicating its effectiveness in enhancing soil carbon sequestration capacity. Although the enhancement of total soil nitrogen content by biochar was small (3.1 to 7.8%), this increase had a positive effect on crop growth. Considering the cost-effectiveness, this study recommends a one-time application of 40 t/ha of biochar, which can maintain the effect for at least 2 years, reducing the need for frequent applications and the associated economic costs.This study provides recommendations for optimization of biochar application and provides a scientific basis for sustainable agricultural development. By improving soil properties and increasing crop yields, this study contributes to the promotion of green development of agriculture and ecological civilization, and the realization of carbon and nutrient cycling in agroecosystems.The significance of this research focuses on evaluating the effects of biochar on soil properties and tomato production, thereby providing a scientific basis for fine-tuning application levels. Such optimization promotes sustainable farming practices, reduces agricultural waste emissions, enhances carbon and nutrient dynamics within agroecosystems, and reinforces the scientific foundation essential for progressing green agricultural development and building an ecological civilization.

Rhizosphere microecological mechanism of carbon sequestration and its emission mitigation in rice ratooning

Rice ratooning plays a critical role in mitigating global climate change and enhancing soil carbon sequestration due to its properties of carbon fixation and emission reduction. The rhizosphere micro-ecosystem emerges as one of the key determinants, thus it is highly significant to investigate the impact changes in rhizosphere microbial composition on the ecological mechanisms associated with carbon sequestration and emission reduction in paddy fields. Over two consecutive years, this study analyzed greenhouse gas emission characteristics, photosynthetic carbon assimilation patterns, and rhizosphere microenvironmental differences between the main crop (MC) and ratoon season rice (RSR) using four rice varieties with distinct growth stages and genetic traits. The results demonstrated that compared to MC, RSR reduced the daily average methane (CH₄) emissions from paddy field by 57.78∼64.31 %, while decreasing the distribution of photosynthetic products to the rhizosphere soil by 78.15 %. 16S rRNA sequencing revealed a significant increase in the abundance of autotrophic microorganisms, and the carbon-fixing bacterium Pseudarthrobacter was isolated and identified in RSR soil. The exogenous addition of this microorganism increased the soil organic carbon (SOC) content of RSR by 4.65 %, while simultaneously reducing CH₄ emissions from paddy fields by 26.25 %. The significant increase in autotrophic carbon-fixing bacteria in the rhizosphere soil is one of the key micro-ecological mechanisms driving carbon sequestration and emission reduction in paddy fields. This is attributed to the reduced allocation of photosynthetic carbon assimilation products to the belowground components, thereby promoting the abundance of autotrophic carbon-fixing bacteria in RSR field. Consequently, the ecological niche width of heterotrophic microorganisms, such as methanogens, is reduced, while autotrophic carbon-fixing bacteria mitigate greenhouse gas emissions from RSR field by fixing CO₂ and increasing SOC content. The findings offer valuable theoretical and practical perspectives on attaining the overarching objectives of carbon neutrality and food security.

Effects of the long-term rice expansion on ecosystem carbon budget in the typical agricultural area of Northeast China

Extensive rice expansion in northeast China has significantly altered land use and land cover (LULC) changes. However, the impact of long-term rice expansion on regional carbon budget dynamics remains unclear. A major obstacle in addressing this gap is the absence of agricultural LULC information with high spatiotemporal resolution. Here, we selected the Sanjiang Plain experienced dramatic rice expansion as the study area, presenting a framework that integrates high-resolution crop distribution data with a process-based model to quantify the impact of rice expansion on regional carbon budgets. Specifically, we employed a robust deep-learning network for crop mapping based on Landsat data, to reconstruct the spatiotemporal dynamics of rice expansion from 1985 to 2020. We then incorporated these long-term crop maps into the Denitrification-Decomposition (DNDC) model, to explore the effects of rice expansion on the regional carbon budget over this period. Analysis results showed that the rice planting area expanded by 708.64 km2/yr, resulting in more than a tenfold increase over the past 36 years. Spatially, rice planting expanded from the southwest to the northeast and from the interior to the exterior. This expansion has resulted in approximately 275 Mt. of CO2 and 6.92 Mt. of CH4 greenhouse gas emissions, altering the dynamics of the regional carbon budget and shifting the ecosystem from a carbon sink to a carbon source since 2016. Although the long-term expansion of rice increased soil respiration and CH4 emissions, it also enhanced soil carbon sequestration through agricultural management practices. These findings greatly enhance our understanding of the ecosystem carbon cycle's response to long-term agricultural LULC changes, providing more accurate data support and scientific evidence for developing low-carbon agricultural policies.

Sustainable strategies for enhancing soil carbon sequestration and their beneficial impacts on soil fertility: A comprehensive review

Soil inoculation with beneficial microbes and biochar is increasingly popular as soil structures degrade and agricultural yields must be maintained with minimal synthetic inputs. While beneficial microorganisms, including plant growth-promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF), and biochar are used as supplements, their application in large-scale agriculture remains limited. The current development of inoculants focuses primarily on improving soil fertility and plant growth, with insufficient attention to their potential for altering soil carbon (C) dynamics. This review explores the current understanding of microbes and biochar-based approaches and the mechanisms by which they enhance soil carbon sequestration (SCS). It addresses the roles of biochar and microbes in acting as physical barriers to C loss, promoting stable soil aggregates, and influencing soil microbial communities. The review underscores the importance of long-term field experiments, standardized methodologies, and widespread implementation of biochar and microbes for SCS, highlighting their potential to enhance soil fertility and mitigate climate change. The proposed integration of biochar and microbes is presented as a promising strategy for generating and maintaining soil C stocks. This analysis is timely, considering the challenges to global agriculture posed by declining soil fertility and the need for more effective sustainable approaches.

Tree species selection for optimizing soil carbon storage: Insights from litter decomposition and bacterial community analysis in coastal ecosystems

Coastal wetland ecosystems are critical sinks for atmospheric carbon dioxide, playing a vital role in global carbon cycling and climate regulation. The decomposition of leaf litter plays a crucial role in the formation and stability of soil organic carbon (SOC) in these environments. This study investigated the impact of leaf litter decomposition from five tree species (Populus deltoids, Ligustrum lucidum, Taxodium 'Zhongshanshan', Hibiscus hamabo, and Nerium oleander) on SOC dynamics, humus composition, and soil bacterial community structure in a tidal flat. Litterbags were used to monitor the mass loss and changes in litter chemical composition over 270 days. The results revealed significant differences in decomposition rates among the tree species, with Nerium oleander exhibiting the fastest decomposition and Populus deltoids the slowest. Surprisingly, initial litter chemistry did not correlate with decomposition rates; however, changes in lignin and hemicellulose content during decomposition were significantly related to mass loss. Despite its rapid decomposition, Nerium oleander litter resulted in the highest accumulation of SOC, total humus, and humin compared to the other species, challenging the conventional view that slower decomposition leads to greater SOC storage. The soil microbial community structure was significantly influenced by SOC, humus, and litter components, with distinct microbial assemblages associated with each tree species. A random forest model identified key bacterial taxa, predominantly Proteobacteria, as important predictors of SOC content, highlighting the role of bacterial diversity in regulating SOC dynamics. These findings underscore the importance of considering litter quality, decomposition dynamics, and bacterial community composition in strategies aimed at enhancing soil carbon sequestration. This study suggests that selecting tree species with rapidly decomposing litter, such as Nerium oleander, in coastal plantations can be an effective management tool for optimizing soil carbon storage, offering valuable insights for mitigating climate change impacts.

Environmental impact of modern agricultural practices: Strategies for reducing carbon footprint and promoting conservation

Modern agricultural practices have significantly transformed food production, leading to increased efficiency and productivity. However, these advancements have also had notable environmental impacts, particularly concerning carbon emissions and resource depletion. This study explores the environmental impact of contemporary agricultural practices, emphasizing the need for strategies to mitigate carbon footprints and enhance conservation efforts. Agriculture contributes substantially to greenhouse gas emissions through sources such as livestock, synthetic fertilizers, and fossil fuel consumption. These emissions contribute to climate change and global warming. Additionally, modern farming practices often lead to deforestation, habitat loss, and soil degradation, exacerbating biodiversity loss and reducing soil health. Water usage in agriculture also poses significant challenges, with high water consumption and pollution from runoff affecting water resources and aquatic ecosystems. To address these issues, several strategies can be employed to reduce the carbon footprint of agriculture. Adoption of sustainable farming practices such as conservation tillage and no-till farming can enhance soil carbon sequestration, improving soil health and reducing emissions. Agroforestry and cover cropping further contribute by capturing atmospheric carbon and improving soil structure. The integration of renewable energy sources like solar and wind power in farming operations, along with energy-efficient technologies, can also reduce reliance on fossil fuels and lower overall greenhouse gas emissions. Promoting conservation involves implementing practices that protect and restore natural resources. Soil conservation methods, including erosion control techniques like terracing and contour plowing, help maintain soil health and prevent degradation. Efficient water management strategies, such as drip irrigation and rainwater harvesting, reduce water consumption and mitigate pollution from runoff. Biodiversity conservation can be supported through the preservation of natural habitats and the promotion of biodiverse farming systems, which enhance ecosystem resilience and stability. Effective policy frameworks and support mechanisms are crucial for driving the adoption of these strategies. Government policies, including environmental regulations and incentives, play a pivotal role in encouraging sustainable practices. Research and innovation are essential for developing new technologies and practices, while education and extension services ensure the dissemination of knowledge and best practices to farmers. Modern agricultural practices have significant environmental impacts, but through the adoption of sustainable practices and innovative strategies, it is possible to reduce carbon footprints and promote conservation. Continued research, supportive policies, and effective implementation of conservation strategies are essential for achieving a more sustainable agricultural future. Keywords: Environmental Impact, Agricultural Practices, Carbon Footprint.

Vegetation restoration enhancing soil carbon sequestration in karst rocky desertification ecosystems: A meta-analysis

Vegetation restoration measures have been increasingly employed to alleviate rocky desertification in karst ecosystems. However, the comprehensive effects of these interventions on soil properties and soil organic carbon (SOC) remain poorly understood. Herein, we gathered 644 paired observations from 68 studies and conducted a meta-analysis to quantify the performance of different vegetation restoration measures including moss (MS), grassland (GL), cash crop (CP), shrub (SH), and secondary forest (SF) through soil properties and SOC. Our results demonstrated significant effects of MS, GL, CP, SH, and SF on soil biotic and abiotic factors, each with distinct response characteristics. Particularly, MS significantly enhanced all soil properties (excluding a slight decrease in soil pH by 10.8%). Moreover, MS, GL, CP, SH, and SF could elevate SOC by 32.1%, 17.6%, 24.9%, 59.2%, and 48.7% respectively. Utilizing random forest and linear regression models, we identified primary drivers for SOC in MS, GL, CP, SH, and SF as soil moisture content, arbuscular mycorrhizal fungi, soil microbial phosphorus, total nitrogen, and β-1,4-glucosidase, respectively. This meta-analysis underlined the varied effects of vegetation restoration measures on soil properties and advocates for restoration measures that prioritize plant productivity and reduce soil temperature during the karst rocky desertification restoration process. Additionally, this study underscores the pivotal role of vegetation rehabilitation in environmental conservation and carbon sequestration of ecologically vulnerable regions.

The Role of Organic Farming for Climate Change Mitigation and Sustainable Development: A Review

Climate Change, exacerbated by human activities such as fossil fuel combustion and greenhouse gas emissions like carbon dioxide (CO2), is a pressing global crisis that disrupts long-term weather patterns, ecosystems, and human well-being. Organic agriculture offers a viable solution to mitigate these effects. By lowering greenhouse gas emissions and enhancing soil carbon sequestration, organic farming strengthens ecosystem resilience. Practices such as eliminating synthetic fertilizers and pesticides, rotating crops, and utilizing organic waste foster robust agricultural systems capable of enduring extreme weather and water scarcity. This paper provides an in-depth analysis of how organic farming contributes to climate change mitigation, detailing practices that support soil carbon sequestration, reduce nitrogen oxide (N2O) emissions, and boost biodiversity. It also addresses challenges such as emissions measurement and consumer behaviour, emphasizing the need for further research and supportive policies. Organic agriculture not only advances sustainable development but also promotes food security and environmental sustainability in the face of climate change.

The Impact of Ecological Land Consolidation Projects on Soil Carbon Sequestration Capacity

Land consolidation is an important measure to expand the scale of arable land, improve the working environment of farmland, enhance agricultural productivity, and improve the production and living conditions of farmers. However, for a long time, land consolidation has remained at the stage of improving agricultural infrastructure. With the proposal of ecological and environmental protection concepts, ecological land consolidation projects are about to emerge. In the process of promoting this project, soil carbon sequestration capacity is one of the most important measures of ecological and environmental protection. Overview of the definition and connotation of soil organic carbon, and analysis of the impact of ecological land remediation projects on soil carbon sequestration capacity. On this basis, an overview of soil carbon sequestration measures in ecological land consolidation projects is provided, providing theoretical support and technical guidance for strengthening carbon sequestration work and enhancing soil carbon sequestration capacity in ecological land consolidation projects.

Easily overlooked petiole traits are key factors that affect soil carbon sequestration in plantations in karst areas

Vegetation restoration in karst areas has shifted from expanding planting areas to the collective enhancement of various ecological functions, especially carbon sequestration. Identifying and regulating key plant functional traits involved in the carbon cycle is an effective approach to increase carbon sequestration. However, reports on the significant contribution of petiole traits to the carbon cycle are scarce. Eucalyptus globulus and Bauhinia purpurea plantations in Liujiang river basin were investigated in this study. Petiole traits, understory characteristics, and soil organic carbon have been measured. The aim is to explore key effect of petiole traits for increasing soil carbon sequestration and to provide scientific evidence for the high-quality development of plantations in karst areas. The results indicate that in Eucalyptus globulus plantations, when the understory vegetation coverage is below 50 %, petioles tend to elongate rather than thicken, leading to an increase in specific petiole length. In Bauhinia purpurea plantations, petioles consistently tend to increase diameter. However, when specific leaf area decreases, specific petiole length increases. In both plantations, an increase in specific petiole length accelerates leaf shedding. It leads to increased litter accumulation so that soil carbon content increases. In Eucalyptus globulus plantations, to enhance soil carbon sequestration as an ecological goal, it is recommended to keep the soil total nitrogen below 1.20 mg/g, to control understory vegetation coverage below 50 %, and to limit the extension of Bidens pilosa. In Bauhinia purpurea plantations, within 100 m of altitude, the soil total nitrogen can be controlled below 1.00 mg/g to increase soil organic carbon from large leaf shedding due to the increase of specific petiole length. At lower altitudes, increasing soil total nitrogen can enhance understory vegetation coverage, allowing soil organic carbon to originate from both leaf shedding and understory vegetation residues.

Spatiotemporal variations and driving factors of farmland soil organic carbon in various landforms of a complex topography

Estimating the spatiotemporal variations and driving factors of farmland soil organic carbon density (SOCD) is of great significance for enhancing soil carbon sequestration capacity. Herein, a large region of complex topography was targeted, which includes hill–mountain, valley–basin, and plain–platform. Based on the massive amounts of sampling data (57,254 measured values) and a large-scale soil map of 1:10,000 (371,976 polygonal patches), the gravity center migration model and gray correlation model were used to quantify the spatiotemporal variations and driving factors of farmland SOCD. The results indicated that the farmland soils in the study area had dual functions of carbon source and sink during 1982–2018, of which 45.50 % and 54.50 % were identified as carbon source and sink, respectively. Specifically, the SOCD for the entire study area, its hill–mountain, and valley–basin increased from 2.79 kg m−2, 2.97 kg m−2, and 3.06 kg m−2 to 2.87 kg m−2, 3.06 kg m−2, and 3.14 kg m−2, respectively, with 0.08 kg m−2 carbon sequestrations and a northeast migration direction for the SOCD gravity center (angle: 21.94°, 23.56°, and 18.82°; distance: 1.56 km, 2.73 km, and 3.20 km). There was a smaller increase of 0.07 kg m−2 in SOCD for the plain–platform from 2.38 kg m−2 (1982) to 2.45 kg m−2 (2018), and the SOCD gravity center migrated to the southwest with an angle of −172.46° and a distance of 1.84 km. Thus, the spatiotemporal variations of farmland SOCD in various landforms varied greatly. Over the past 36 years, SOCD variations were driven by a combination of intrinsic soil factors and external factors such as human disturbance. However, the driving effects of these factors on the landforms of hill–mountain, valley–basin, and plain–platform were quite different in size and order. Therefore, we suggest that topography must be considered when formulating policies to improve soil carbon sequestration, and priority should be given to landform-specific SOCD variation and the factors contributing to them.

Enhancing lucerne (Medicago sativa) yield and nutritional quality: a meta-analysis of fertilization types and environmental factors in China.

Lucerne (Medicago sativa), is a cornerstone of China's livestock industry, however, due to the backward agronomic strategies and technology, lucerne in China faces cultivation challenges that result in lower productivity and quality than global standards. Therefore, we undertook a meta-analysis to evaluate the impact of five distinct fertilization types on lucerne yield and nutritional quality in various locations in China. The fertilizer practices included manure application, combined mineral fertilizer and manure application (FM), biological fertilizer application, unbalanced application of two or more mineral fertilizer types, and balanced mineral fertilizer application. Furthermore, we investigate influential factors of yield and quality of lucerne under fertilization, including climatic variables (mean annual precipitation, mean annual temperature), initial soil properties (soil organic carbon; total nitrogen, pH), and agronomic factors (seeding rate, harvest frequency, and lucerne stand age). Our study analyzed 53 published papers to discern the most beneficial fertilizer for enhancing lucerne yield and nutritional quality. The results showed that the fertilizer practices, on average, significantly improved yield by 31.72% and crude protein content by 11.29%, with FM emerging as the most effective, this is because mineral fertilizers provide available nutrients for lucerne, manure provides essential organic matter for microorganisms and improve soil properties. In addition, the fertilizer practices significantly reduced neutral and acid detergent fiber contents by 6.28% and 8.50%, respectively, while increasing ash content and relative feeding value. Furthermore, climatic variables, soil properties, and planting system factors such as sowing date and harvest frequency significantly affected yield and nutritional quality. The practical implications of our results emphasize the need for balanced and strategic fertilizer application to optimize lucerne production and highlight the potential to adjust cultivation practices according to environmental conditions. Balanced and strategic fertilizer application can simultaneously improve soil properties, enhance soil carbon sequestration, and reduce the emission of greenhouse gases from the soil, which is a vital measure for realizing sustainable agricultural development.

Soil carbon offset markets are not a just climate solution

There is growing interest in enhancing soil carbon sequestration (SCS) as a climate mitigation strategy, including neutralizing atmospheric emissions from fossil‐fuel combustion through the development of soil carbon offset markets. Several studies have focused on refining estimates of the magnitude of potential SCS or on developing methods for soil carbon quantification in markets. We call on scientists and policy makers to resist assimilating soils into carbon offset markets due to not only fundamental flaws in the logic of these markets to reach climate neutrality but also environmental justice concerns. Here, we first highlight how carbon offset markets rely on an inappropriate substitution of inert fossil carbon with dynamic stocks of soil carbon. We then note the failure of these markets to account for intersecting anthropogenic perturbations to the carbon cycle, including the soil carbon debt and ongoing agricultural emissions. Next, we invite scientists to consider soil functions beyond productivity and profitability. Finally, we describe and support historical opposition to offset markets by environmental justice advocates. We encourage scientists to consider how their research and communications can promote diverse soil functions and just climate‐change mitigation.

Applying conditioners to address the issues of carbon loss and cadmium pollution in the karst paddy-oil crop system

The fragile ecosystem and unique parent material in the karst region lead to severe carbon loss and cadmium pollution. Additionally, the rice-oilseed rotation system exacerbates the accumulation of cadmium in crops. Therefore, it is necessary to find a sustainable land use approach that ensures crop quality while promoting soil carbon sequestration. This article provides an overview of cutting-edge technologies to enhance soil carbon sequestration capacity, and it discovers that the application of amendments has a significant effect on reducing cadmium content in crops and improving soil organic carbon levels. Through experimental analysis, The results indicate that the conditioner in group T4 (Humic acids) can effectively passivate cadmium elements in the soil, reducing the cadmium content in rice and rapeseed tissues. Overall, our research indicates that humic acid amendments not only enhance soil carbon sequestration capacity but also significantly reduce cadmium content in crops and increase crop yields. These findings highlight the significant value of humic acid amendments in the rice-oilseed rotation system in the karst region, providing scientific evidence and theoretical support for promoting sustainable development in the area.

Hyperspectral sensing and mapping of soil carbon content for amending within-field heterogeneity of soil fertility and enhancing soil carbon sequestration

Hyperspectral sensing and mapping of soil carbon content for amending within-field heterogeneity of soil fertility and enhancing soil carbon sequestration