Search Results (92)

On the North China Plain, the winter wheat season is poorly synchronized with precipitation, making the traditional winter wheat–summer maize system heavily dependent on supplemental irrigation and associated carbon inputs. Based on a split-plot field experiment in Shenzhou, Hebei, from October 2022 to October 2025, this study evaluated the trade-off between annual system yield and area-scaled carbon emission among six cropping systems under conventional irrigation (CK) and rainfed management (R). The winter wheat–summer maize system (WM) maintained the highest grain-oriented annual system yield (22.91 t ha⁻¹ yr⁻¹ under CK), but it also showed the highest area-scaled carbon emission (11.97 t CO₂-eq ha⁻¹ yr⁻¹). The winter wheat–summer maize–spring maize system (WMM) reduced area-scaled carbon cost relative to WM (8.97 vs. 11.97 t CO₂-eq ha⁻¹ yr⁻¹ under CK), whereas its product-scaled carbon footprint remained comparable to or slightly higher than that of WM. Under a unified dry-matter basis, the double silage-maize system (FM) showed the lowest dry-matter-scaled carbon footprint (CF_DM; 193.85 and 175.71 kg CO₂-eq t DM⁻¹ under CK and R, respectively). Soil respiration in 2025 varied mainly with observation date and cropping-system configuration, and soil organic carbon (SOC) stock at the 2025 harvest differed among cropping systems, water-management regimes, and soil depths. Overall, WM remained the highest-yielding option under a grain-supply objective, whereas FM, the ryegrass–early-summer maize system (RM), and the forage winter wheat–early-summer maize system (FWM) were relatively more suitable under multifunctional biomass-supply and low-carbon-transition objectives. Full article

Agricultural soils play a dual role in the climate system, acting both as carbon sinks and natural sources of greenhouse gas emissions, which may be intensified under unsustainable management. However, the comparative effectiveness of different soil management strategies, particularly organic amendments derived from agro-industrial residues, remains insufficiently clarified. This review aims to critically synthesize current scientific evidence on soil stewardship practices for mitigating greenhouse gas emissions and enhancing soil carbon sequestration. The analysis is based on a structured review of peer-reviewed literature published over the last decade, including field experiments, long-term trials, and LCA studies. Comparative insights are provided across conventional mineral fertilization, organic amendments, and circular fertilization approaches based on agro-industrial by-products. The results indicate that organic amendments such as compost, digestate, and vermicompost generally increase soil organic carbon stocks (up to +40% in long-term systems) and can reduce greenhouse gas emissions and carbon footprint compared with mineral fertilization, although responses vary depending on soil, climate, and management conditions. The review evaluates the effects of different management practices on soil organic carbon dynamics, greenhouse gas fluxes, nutrient use efficiency, and soil biological functioning. Special emphasis is placed on the role of waste-derived fertilizers—such as composts, digestates, and vermicompost—in promoting soil carbon stabilization while reducing the environmental burden associated with synthetic inputs. Evidence consistently indicates that soil stewardship strategies grounded in circular economy principles can lower net carbon footprints, improve soil resilience, and mitigate trade-offs between productivity and climate mitigation. By framing soil management within the context of global warming mitigation, this review highlights the multifunctional role of soils as climate regulators and underscores the potential of agro-industrial waste valorization as a scalable pathway toward climate-smart and low-emission agricultural systems. Full article

Employing eco-friendly and low-carbon methods to restore petroleum-polluted soil is a growing trend. However, the low-carbon remediation theories and methods for petroleum-polluted soil are still in their early stages. Herein, the carbon footprint and environmental impacts of different petroleum-polluted soil remediation methods were studied based on life cycle assessment (LCA). It was found that the carbon footprint and environmental impacts of the solidification/stabilization (S/S) method were much lower than those of pyrolysis and chemical oxidation methods. Moreover, compared with other S/S materials, the carbon footprint of lime–fly ash solidification for petroleum-polluted soil was the lowest, at only 12.72 kg CO₂ eq. Moreover, its unconfined compressive strength (UCS) increased by 700% compared to the untreated petroleum-polluted soil. On this basis, the response surface method was further employed to optimize remediation parameters using carbon footprint and UCS growth rate as response variables. The results showed that the optimal parameters for solidifying petroleum-polluted soil were lime content of 10.41%, fly ash content of 21.89%, and a curing time of 27 days. This study provides the important theoretical basis and practical guidance for the low-carbon and efficient remediation of petroleum-polluted soil. Full article

Population growth and rapid urbanization have significantly increased construction activities and the demand for building materials. It is estimated that approximately 39% of global CO₂ emissions are associated with the construction sector, with nearly 8% directly attributed to Portland cement production. In addition to greenhouse gas emissions, the cement industry is responsible for substantial environmental impacts, including natural resource depletion, soil degradation, and air and water pollution. In this context, the development of alternative and more sustainable binder systems has become a global research priority. Geopolymers have emerged as promising materials produced through either alkaline or acid activation routes, offering advantages such as a reduced carbon footprint, high durability, and rapid strength development. Among these systems, acid-activated materials, particularly phosphate-based geopolymers, differ fundamentally from conventional alkali-activated binders in terms of reaction chemistry and binding phases. The formation of aluminum phosphate (AlPO₄) networks plays a key role in governing the mechanical performance and microstructural stability of these materials. This mini-review provides a critical overview of the fundamental principles of acid activation applied to alternative cementitious materials, with emphasis on dissolution mechanisms, polycondensation reactions, and the nature of binding phases in phosphate-based systems. Unlike previous reviews, this study integrates recent findings on reaction mechanisms with a comparative analysis between acid and alkaline activation routes, highlighting underexplored aspects of precursor reactivity and binder formation. The main types of acids used as activators, the influence of precursor chemical composition, and the conceptual differences between acid and alkaline activation are discussed. In addition, recent advances, current challenges, and future perspectives of acid activation are addressed, highlighting its potential as a viable low-carbon binder route for sustainable construction materials, with strong prospects for partially replacing Portland cement, particularly in high-performance applications requiring enhanced chemical resistance and thermal stability. Full article

Although trenchless technology is widely recognized for its low-carbon potential, existing assessment models often overlook the significant impact of regional geological variations on energy consumption. Based on the EN 15804 standard and the Input–Process–Output (IPO) model, this study establishes a high-resolution carbon emission assessment framework focusing on the “Upfront Carbon” stages (Modules A1–A5) of public works. An empirical study was conducted on a sewage microtunneling project in Hualien, Taiwan, characterized by a deep burial depth of 12 m and challenging gravel formations (SPT N-value > 50). Life Cycle Assessment (LCA) principles were adopted to quantify the carbon footprint and benchmark the results against international guidelines from the UK (PJA) and Japan (JSWA). The Life Cycle Inventory (LCI) reveals a unit emission intensity of 349 kgCO₂e/m, significantly higher than international benchmarks. Critical findings indicate that this discrepancy is primarily driven by environmental variables—specifically, geological resistance and grid emission factors. Crucially, the sensitivity analysis demonstrates that the physical resistance of the hard gravel layer increased machinery energy intensity by 18.7% compared to baseline soil conditions. This study officially defines this phenomenon as the “Geological Premium.” Additionally, carbon efficiency was found to be profoundly influenced by the regional grid emission factor (Taiwan: 0.495 vs. UK: 0.193 kgCO₂/kWh). This research establishes a localized empirical database and validates the necessity of expanding assessment boundaries to include auxiliary works in geologically complex regions. The developed framework provides a scalable solution for optimizing embodied carbon in urban infrastructure, offering policymakers a robust scientific basis for implementing precise “Green Public Procurement” and carbon budgeting strategies. Full article

The analysis of water and emission efficiency in cropping systems is vital for sustainable agriculture in Mediterranean regions, which face increasing water shortages. This study offers a site-specific assessment of the Water Footprint (WFP) and Carbon Footprint (CFP) of organic cotton grown under Mediterranean conditions, integrating environmental indicator measurements with economic valuation of greenhouse gas (GHG) emissions via the EU Emissions Trading System (ETS) and the Social Cost of Carbon (SCC). Experiments were carried out at three sites with different soil types, testing two cultivars (Armonia and ST-318) under three irrigation scenarios: severe water deficit (I30), moderate water deficit (I70), and full irrigation (I100). The results reveal significant site-specific variability, with average WFP_lint values ranging from about 1.440 m³ per ton at the most productive site to over 4.100 m³ per ton at the least productive site. Similarly, CFP_lint is lower under high-yield conditions, emphasizing the strong influence of yield on mass-based indicators. At the Carboj and Primosole sites, shifting from (I30) to I100 results in roughly a 50% reduction in emissions, while at Buonfornello, increased irrigation does not consistently produce benefits. The cultivar response is key: Armonia shows greater resilience to water stress, while ST-318 performs best with full irrigation. Overall, the findings highlight that the sustainability of the Mediterranean cotton system depends on factors such as yield performance, site-specific conditions, and cultivar choice. Full article

Cement is one of the primary construction materials in ground improvement applications that employ the binder stabilization method. Due to the high carbon dioxide emissions in its production, evaluating environmentally friendly alternative binder materials is a popular research topic. Industrial by-products such as fly ash (FA) and ground granulated blast-furnace slag (GGBS) are alternatives to traditional cement, especially in deep soil mixing (DSM) applications, and can enhance sustainability in construction projects. Since these materials are not active when used alone, alkali activation is proposed to modify them as binding agents in ground improvement projects. This study presents the outcomes of a primary laboratory test phase for on-site applications. FA and GGBS precursors supplied by local plants, mixed with soil and activator solutions in applicable ratios, and samples were prepared for laboratory tests. Unconfined compression tests were applied with strain measurements after several curing durations, between 1 and 54 weeks. Average compression strength and modulus of elasticity values were recorded at approximately 12.3 MPa and 11.7 GPa, respectively, in samples with an average dosage. An empirical correlation between the strength and stiffness modulus was found. Strength and stiffness values were comparable to traditional materials, indicating the potential of these industrial by-products when activated under alkali conditions. The carbon footprints of cement and alkali-activated by-products were compared based on calculated CO₂-eq emissions. Full article

This study introduces a novel approach to producing carbon-negative food ingredients by integrating phycocyanin extraction from Spirulina (Arthrospira platensis) with the application of its residual biomass as a biostimulant for soil organic carbon (SOC) sequestration. A comprehensive life cycle assessment (LCA) was conducted to evaluate the environmental performance of this integrated system, encompassing geothermally powered Spirulina cultivation, phycocyanin extraction, and the use of the waste stream to enhance SOC in degraded Icelandic soils. Although the cultivation and extraction processes are associated with environmental impacts, the SOC sequestration resulting from biostimulant application more than offsets these burdens—yielding a net-carbon-negative natural food colorant under the assumptions applied in this study (−1.60 tCO₂-eq per color unit). This work highlights the potential for such ingredients to contribute meaningfully to Scope 3 emission reductions, in line with science-based targets and the GHG Protocol. Traditionally, food pigments have been overlooked in carbon accounting due to their low inclusion rates and perceived minimal contribution to overall product footprints. This study reframes natural colorants as strategic levers for climate action, offering a pathway for food manufacturers to advance decarbonization while transitioning toward more sustainable, bio-based ingredients. Full article

Future climate change poses unprecedented challenges to agricultural production worldwide. Therefore, designing region-specific rotation patterns is crucial for achieving synergies among multiple objectives, including agricultural productivity and ecological conservation. Based on a long-term field experiment in the Northern Agro-pastoral Ecotone of China, we calibrated and validated the Agricultural Production Systems Simulator (APSIM) and simulated rotation patterns involving four representative crops under eight climate scenarios, including warming, extreme precipitation, and combined temperature–precipitation changes. Analysis combined with carbon footprint assessment was employed to quantitatively evaluate the productivity, ecological benefits, and economic returns of different rotation patterns. The results showed that warming generally reduced crop productivity and economic returns, weakened soil carbon sequestration, and increased net carbon emissions across rotation patterns. Increasing intensity of extreme precipitation further constrained the capacity of rotation patterns to enhance yields, improve incomes, and reduce carbon emissions. Under scenarios of warming and extreme precipitation, the faba bean–oat rotation pattern was found to be the most effective for increasing crop yields, while the faba bean–potato rotation is beneficial for enhancing the incomes from local agriculture. The potato–faba bean rotation pattern was most effective for environmental sustainability due to low net carbon emissions. The findings provide a scientific basis for developing diversified planting strategies with synergistic multi-objectives in the Northern Agro-pastoral Ecotone of China, contributing to food security and sustainable agricultural development under a changing climate focused on changes in temperature and precipitation. Nevertheless, the potential effects of rising atmospheric CO₂ concentrations may be incorporated in future studies. Full article

Climate change induced by greenhouse gas emissions is currently one of the most important challenges of the world. Against this backdrop, we deeply explore the temporal variation characteristics of vegetable production in Guangdong Province, a major province of China from the carbon footprint perspective. The aim is to promote the reduction of greenhouse gas emissions from agricultural production and carbon sequestration, as well as sustainable agricultural development. We primarily adopted the carbon emission coefficient provided by Intergovernmental Panel on Climate Change and utilized data from the China Rural Statistical Yearbook and the Guangdong Rural Statistical Yearbook from 1990 to 2022 to analyze the changing characteristics of the carbon footprint of vegetable production in Guangdong Province. In addition, we used the grey prediction model GM (1, 1) to estimate the parameters and test the residual. Then, the carbon emission of vegetable production in Guangdong province was predicted from 2023 to 2060. The research results show that agricultural input is the largest source of carbon emissions, accounting for 51.99–66.55%, followed by farmland soil utilization (33.45–48.01%). Within agricultural input, fertilizers, pesticides, and mulching films are the main sources of carbon emissions. Based on the data from 2011 to 2022, it is predicted that the net carbon emissions of vegetable production in Guangdong Province will continue to decline after 2022. Based on the above findings, it is suggested to promote the sustainable development of the vegetable industry by increasing policy support for the R&D and promotion of green and low-carbon technologies and green vegetable production, reducing agricultural input, and promoting the formation of the low-carbon production concept. Full article

Climate change has led to rising temperatures and increasingly extreme weather conditions, largely driven by human activity, including agriculture. The food and agriculture sector is responsible for approximately 21–37% of global greenhouse gas (GHG) emissions. In response to climate change, various innovative agricultural systems have emerged in recent decades. Among them, soilless systems represent revolutionary methods for producing large quantities of vegetables while using fewer inputs, including water, fertilizers, and pesticides. This study assesses the carbon footprint of two greenhouse-based lettuce (cv. Romana) growing systems using a cradle-to-gate life cycle assessment (LCA) approach. The first system employs an aeroponic growing method, whereas the second relies on a soil-based growing method within the greenhouse. To contextualize their environmental performance, the carbon footprints of these greenhouse cultivation systems are compared with those of the outdoor pot system. Results indicate that the highest Global Warming Potential (GWP) is associated with soil-based cultivation in the greenhouse, reaching 7.98 kg CO₂eq per kilogram of fresh weight (FW) lettuce, followed by the outdoor pot system (1.72 kg CO₂eq/kg), while the aeroponic system demonstrates the lowest GWP, achieving 0.98 kg CO₂eq/kg. The greenhouse structure contributed 9357.93 kg CO₂eq to the total GWP, representing 23% of the total impact in the aeroponic system and 22.7% in the soil-based greenhouse system. These findings suggest that soilless cultivation systems can provide a more sustainable and higher-yield alternative to soil-based methods, potentially reducing the environmental impact of vegetable production in the Mediterranean region. Full article

In this study, the aim was to improve the mechanical and durability properties of kaolin clay (KC)-based soil by stabilizing it with geopolymer and natural fiber. In the production of the geopolymer, rice husk ash (RHA) was used as a binder, sodium metasilicate (SMS) as an activator, and another hemp fiber (HF)was used for soil stabilization. Within the scope of the presented study, RHA and SMS were used at three different rates (5%, 7.5%, and 10%), while HF was used in six different volumes (0.5%, 1%, 1.5%, 2%, 2.5%, and 3%) and two different lengths (6 and 12 mm). The study also examined how much water was in the combinations, which was measured at the optimum level and at −5, +5, and +10 compared to the optimum level. The unconfined compressive strength (UCS) was used to check the mechanical qualities of the test specimens and 5- and 10-cycle freeze–thaw (F-T) tests to check the durability properties. The test results indicated that the mixed formulation with 5% RHA, 10% SMS, 2.5% HF, and the optimum water content resulted in the best results for both the UCS and F-T tests. The SEM investigation for this mix found that the microstructural properties for the specimen were directly related to the dense gel phases and the strong fiber–matrix bonding. According to the carbon emissions (CO₂-e) and carbon index (CI) analysis from the mix component analyses, it was found that the HF-strengthened geopolymer is a sustainable solution for soil stabilization. The optimum mixture achieved a UCS of 1202 kPa (4.5 times higher than untreated soil), while the strength losses after 10 freeze–thaw cycles were reduced to below 10% in optimized compositions. The carbon index (CI) decreased by up to 65%, demonstrating the strong sustainability benefits of the proposed system. The novelty of this study lies in the combined use of hemp fiber (HF) and rice husk ash (RHA)–sodium metasilicate (SMS)-based geopolymer for kaolin clay stabilization, which has not been comprehensively investigated in previous research. Unlike traditional studies focusing on either geopolymer or natural fiber reinforcement alone, this work simultaneously evaluates the mechanical performance, freeze–thaw durability, microstructural evolution, and carbon footprint to develop a fully sustainable soil improvement framework. Full article

Banana plantations are important tropical agro-ecosystems, and quantifying their greenhouse gas emissions is essential for developing low-carbon agriculture and mitigating global warming. The carbon balance of two banana cultivars (Musa paradisiaca AA (MA) and M. AAA Cavendish var. Brazil (MB)) was evaluated using the life cycle assessment (LCA) approach, based on field trials and farmer surveys in Chengmai County, Hainan Province, China. The results indicated that (1) both cultivation systems functioned as net carbon sinks, and the MB cultivar demonstrated a superior carbon balance, with a net sequestration of 21,652.88 kg CO₂ eq·ha⁻¹, significantly higher than the MA cultivar (15,197.96 kg CO₂ eq·ha⁻¹); (2) fertilizer management was the dominant source of anthropogenic emissions, contributing 74.03–81.76% of the carbon footprint from agricultural inputs; and (3) the MB cultivar’s enhanced carbon fixation capacity outweighed its higher emissions, resulting in a more favorable carbon balance than the MA cultivar. Concurrently, the banana plantations significantly increased soil carbon sequestration by 13.47–24.48%. Thus, within the studied system boundary, banana agro-ecosystems serve as net carbon sinks, a function that can be enhanced by optimizing fertilizer management to reduce emissions and by increasing both plant biomass and soil carbon sequestration. These results provide a scientific basis for low-carbon practices and promoting a more sustainable banana industry. Full article

Viticulture in insular and volcanic environments faces mounting pressures from land abandonment, limited mechanization, and climate-related stress on soil and water resources. This study develops an integrated framework combining Life Cycle Assessment (LCA) and soil diagnostics to evaluate the environmental and agronomic performance of vineyards on the island of Tenerife (Canary Islands, Spain). Fifteen representative vineyards located between 100 and 1000 m a.s.l. within the Tacoronte–Acentejo Denomination of Origin were assessed using the ReCiPe 2016 Midpoint (H) method and the Ecoinvent 3.8 database. The average carbon footprint reached 1.40 kg CO₂-eq kg⁻¹ of grapes, with diesel use for field access and transport contributing over 50% of total impacts and 64% of human toxicity. Copper-based fungicides accounted for ~11% of impacts, underscoring their environmental persistence. Soil analyses revealed widespread Ca/Mg imbalances and sporadic K deficiencies, while organic matter and pH levels were generally adequate. Importantly, vineyards with balanced nutrient ratios exhibited both higher yields and lower environmental burdens, suggesting that improved soil health can enhance eco-efficiency, primarily by supporting higher yields under similar input regimes. Targeted strategies—such as magnesium supplementation, reduced copper inputs, and low-carbon mobility practices—can therefore mitigate emissions while improving productivity. The proposed LCA–soil integration provides a replicable model for sustainable resource management and climate-resilient viticulture in other fragile and topographically constrained agricultural systems. Full article

Arbuscular mycorrhizal fungi (AMF) form symbiotic relationships with most crops. They function as promising sustainable agricultural amendments by synergizing with biochar to enhance plant nutrient uptake. However, the effects of AMF and biochar interactions on the yield and nutrient uptake of leguminous crops and the underlying mechanisms remain insufficiently understood. This study employed a two-factor experimental design. Under the baseline conditions of no fertilization (CK), chemical fertilizer application (CF), and biochar-based fertilizer application (BF), treatments with and without AMF inoculation were established, resulting in a total of six experimental treatments. Compared to BF treatment alone, the combined application of AMF and BF (AM + BF) synergistically increased soybean biomass (12.81%) and grain yield (19.45%). This synergistic effect was accompanied by increased plant nitrogen (14.04%) and potassium (21.82%) accumulation. Notably, despite the highest yield, the AM + BF treatment showed a 22.22% reduction in nodule formation rate. This reveals that plant nitrogen acquisition strategies have shifted from relying on biological nitrogen fixation to efficient mycorrhizal pathways, reflecting an inherent optimization of carbon economy. The PLS-SEM model revealed that AMF inoculation altered yield-driving mechanisms: in the absence of AMF, yield could be directly predicted by soil nutrient levels; however, this relationship was disrupted after AMF inoculation. The soil nutrient pathway became non-significant, indicating a transition from a soil chemistry-dependent model to a biologically driven one, where AMF–plant symbiosis became the primary regulator of nutrient uptake. These findings highlight that AMF-BF synergy creates a novel soil–plant feedback mechanism that enhances nutrient acquisition efficiency and optimizes carbon allocation, providing a sustainable approach to boost legume crop yields and reduce environmental footprints. Full article