Eco-efficiency Index Research Articles

Sustainable Development Objetive 12: Eco-Efficiency Ratio of the District Municipality of Campoverde, Province of Coronel Portillo - Peru

Objective: Determine the eco-efficiency index of the District Municipality of Campoverde, 2023. Method: To diagnose the eco-efficiency baseline, the 2016 Eco-efficiency Guide for Public Sector Institutions from the Ministry of the Environment was used. The Delphi survey was applied to experts to determine the importance of the eco-efficiency indices, and for the eco-efficiency index itself, th Manuel Emilio Reátegui Ingae methodology for estimating the level of sustainable development of territories was employed. Results: The consumption indicators are: 22.47 kWh/worker/month (electricity), 39.16 gallons/vehicle/month (90-octane gasoline), 124.14 gallons/vehicle/month (diesel), 3.48 m³/worker/month (water), 0.01 kg/worker/month (paper and ink or toner) and 0.02 kg/worker/month (other papers). Originality/Value: By determining the state of eco-efficiency, measures can be taken to improve the consumption of resources demanded by the District Municipality of Campoverde.

Life cycle assessment as a circular economy strategy to select eco-efficient raw materials for particleboard production

Life Cycle Assessment (LCA) is applied for choosing and comparing circular alternatives, comprising a bicomponent polyurethane resin based on castor oil (PU) and sugarcane bagasse (SB) particles to conventional materials using urea formaldehyde (UF) and eucalyptus particles, for the production of 1 m3 of medium-density particleboard (MDP), from cradle-to-gate, with five different formulations. Databases were used in life cycle inventory and the ReCiPe impact method was selected at midpoint level. The eco-efficiency index, based on modulus of rupture and CO2 emissions, revealed that the best condition was the panels using alternative materials, as it can reduce up to 74 % the environmental burdens investigated. The panel using only circular materials showed feasible technical performance according with the physical-mechanical properties considered, generating the best eco-efficiency indicator (0,154 MPa/CO2 eq.). These results build a foundation for reconsidering the selection of raw materials in large-scale MDP production, potentially leading to the adoption of more sustainable practices.

Exploring sustainable agricultural production models to coordinate system productivity, soil biological health and eco-efficiency in the semi-arid region

Designing sustainable agricultural models is imperative to enhance farm productivity, and soil health with minimum ecological footprints. Therefore, three cropping systems viz., maize-mustard (M-Mus), maize + cowpea-mustard (M + C-Mus), pigeon pea-wheat (PP-W) were tested under four production scenarios viz., integrated organic management (IOM), integrated crop management (ICM), conventional system (CS), and conservation agriculture (CA) for three consecutive years (2018–2021) to find out the productive, soil supportive, and eco-efficient production model. The ICM recorded significantly higher system productivity i.e. 12107, 12889, and 12866 kg ha−1 during 2018–19, 2019–20, and 20–21 over other production system, respectively. Among the cropping systems, the PP-W system registered the maximum system productivity of 12007.0 kg ha−1 during 2018–19, 11899 kg ha−1 in 2019–20, and 12247 kg ha−1 during 20–21. This led to ∼15% higher average system productivity over the maize-mustard system. Nutrient (N, P, and K) acquisition was the highest by the M + C-Mus system followed by the PP-W system. All soil biological indicators considerably improved under IOM followed by ICM across the soil profile after three years. Cultivation of the PP-W system under IOM registered the highest energy use efficiency (73.24). Concerning the eco-efficiency index (EEI), cultivation of PP-W under the IOM production scenario registered ∼ 2.85 times higher EEI (0.20 US$ MJ−1) over the M-Mus cropping under CS. Thus, findings inferred that legume-embedded systems under either IOM or ICM production scenarios are sustainable production models for fetching higher profitability with minimum environmental impact under semi-arid regions.

Compliance with the SDGS: Eco-Efficiency Index of Thedistrict Municipality of Pichanaqui, Province Ofchanchamayo - Peru

Objective: Determine the eco-efficiency index of the District Municipality of Pichanaqui from June to December 2023. Method: The methodology of the Ministry of Environment of 2016 was used to diagnose the eco-efficiency baseline, to determine the degree of importance of the eco-efficiency indexes, the Delphi survey was applied and the methodology to estimate the level of sustainable development of territories was used for the eco-efficiency index. Results: The eco-efficiency index result was 0.52, representing an unstable state of eco-efficiency. Contribution: It will help the municipality obtain greater value with a lower consumption of resources or raw materials for the production of goods or services they produce, in addition to mitigating the negative effects on the environment that directly or indirectly affect society.

The eco-efficiency of fisheries in EU countries

The main goal of this article was to (1) assess the dynamics of eco-efficiency of fisheries in EU countries and its components and (2) identify potential sources of inefficiencies and efficiency surpluses through slack analysis. The hybrid data envelopment analysis (DEA) model was used for the 2008-2019 period. Progress in eco-efficiency was found among 11 countries (out of 23), but the average eco-efficiency index for the sample was 0.988. Differences in the levels and dynamics of eco-efficiency between the studied countries were mainly driven by the efficiency change component, i.e. internal factors. The largest input-saving potential was found in relation to number of employees and gross tonnage of the vessel, suggesting that sample countries deal with the problem of overinvestment and overstaffing. We also found that greenhouse gas emissions could be reduced by approximately a third.

An AHP based sustainability assessment of cement mortar with synergistic utilization of granite cutting waste

The valorization of various waste in construction sector is viewed as a sustainable measure. Protecting natural resources and minimizing waste lays the foundation for sustainable development. The study is aimed to identify the optimum utilization of granite cutting waste (GCW) in sustainable rendering mortar development. The comprehensive study is performed for cement mortar mix of 1:3 (volumetric) by replacing natural sand with 10 % range up to 50 % by GCW powder. The mortar is evaluated for flowability, Fresh density, Compressive resistance, Flexural resistance, Adhesiveness with substrate, Drying shrinkage, Water absorption capacity, Percentage voids, Hardened bulk density, Ultrasonic Pulse Velocity, and Dynamic Modulus of Elasticity parameters. It is observed that, for 30 % replacement, the compressive strength increased by 75 % compared to control mortar for the 28 days curing period. The maximum flexural strength 2.99 N/mm2 is achieved for 30 %, and the highest adhesive strength, 0.89 N/mm2, is noted for 20 % replacement. Also, the microstructural studies are performed to assess the effect on the hydration of the cement. The sustainability evaluation, performed by life cycle assessment methodology, revealed that higher substitution of GCW helps in lowering the environmental impacts for cradle to gate life cycle phase of the mortar. Abiotic depletion potential Fossil Fuels and Ozone depletion potential has contributed to 19.56 and 18.82 % lower impacts for 20 % substitution by granite. The mortar mixes with varied substitutes of granite waste were also evaluated and ranked using the Analytical Hierarchy Process (AHP). In comparison to conventional rendering mortar, the AHP findings show that the mortar mix with 30 % granite waste integration scores highest above all other replacements, indicating its potential as an efficient and environmentally friendly choice. The GP50 mortar mix rated highest on Eco-efficiency index result. However, at optimum substitution of 30 %, the eco-efficiency index lies above average line.

Eco-efficiency analysis and intensification of the monochlorobenzene separation process through double-effect strategy

Distillation is an energy-intensive operation with high capital and operational costs. For this reason, intensification technologies have been developed to significantly reduce the energy usage, utility costs, and carbon footprint of modern chemical plants. In this work, a double-effect intensification strategy with heat integration was proposed for an industrial-scale monochlorobenzene separation process that can be used in a retrofit design. The conventional process and the intensification configurations were designed by simulation in UniSim software. A utility plant with cooling water and steam generation sections was also considered for realistic results regarding water consumption, CO2 emissions, and utility costs. Additionally, in order to establish a qualitative and quantitative overall analysis, such indicators were grouped in a joint evaluation method using the Comparative Eco-Efficiency Index. The proposed configuration provides savings of 60.15 % and 61.79 % in energy and water consumption, respectively; therefore, savings of 60.15 % and 60.20 % in CO2 emissions and utility costs were achieved, respectively, which increased the process's eco-efficiency by 84.57 % and decreased the TAC criterion by 29.65 %. Thus, the new design prove to be a convenient strategy since it significantly improved the original process performance in alignment with the United Nations’ Sustainable Development Goals.

Environmentally adjusted technical efficiency and the impact of energy and transport taxes on the eco-efficiency index of Greek industry

This study aims to investigate the ecological efficiency of industry in Greece through a sector-wise framework using data envelopment analysis and considering three different types of environmental emissions. Through this quantification, it is possible to determine the degree of internalization of the environmental impact for each sector of the Greek economy. This fact supports the administrative decision-making process for the planning of sustainable industrial development. Subsequently, the effect of energy and transportation taxes on the eco-efficiency index is examined. It is shown that the revenues from the collection of environmental taxes in Greece have not been sufficiently used to improve eco-efficiency. This fact underlines the need to achieve long-term economic development that is compatible with environmental goals and social needs through appropriate strategic decisions and measures. It also highlights the need to create a well-designed tax system in order to reduce environmental pollution and improve environmental quality.

Eco-efficiency analysis and intensification of cryogenic extractive distillation process for separating CO2–C2H6 azeotrope through vapor recompression strategy

The cryogenic extractive distillation process for CO2-ethane separation from natural gas involves four distillation columns in series and a rather high amount of energy from boiler and refrigeration compressors. This study proposes the intensification of a real plant located in China using a vapor recompression (VR) strategy to revamp it. The conventional process and the intensification configurations were designed by simulation in UniSim software. A utility plant with cooling water, steam generation, and propane refrigeration sections was also considered for realistic results regarding water consumption, CO2 emissions, and utility costs. Additionally, in order to establish an overall means for performance analysis, such indicators were grouped in a joint evaluation approach using the Comparative Eco-Efficiency Index. Results show that the VR1 scheme applied between the depropanizer condenser and the deethanizer reboiler provides savings of 24.2 % and 24.5 % in energy and water consumption, respectively; therefore, savings of 25.5 % and 21.4 % in CO2 emissions and utility costs were achieved, respectively, which increased the process's eco-efficiency by 41.9 %. As a point of interest, 33 months are necessary to recover the corresponding investment on the compressor and heat exchanger.

Eco-efficiency index of the recycling process of fuel husks into briquettes in Tofu SMEs using life cycle assessment

The increasing demand for energy and the decreasing availability of fossil fuel reserves necessitate the exploration of alternative solutions. Biomass waste, particularly abundant in countries like Indonesia, presents a cost-effective and environmentally friendly energy alternative by reducing CO2 emissions. Transforming waste into a more valuable product is crucial, accompanied by an assessment of its ecological consequences. Nevertheless, the recycling procedure often still consumes materials and energy. Previous research on evaluating the environmental consequences of recycling organic waste into briquettes remains limited. This investigation is focused on analyzing the environmental effects of the recycling process for converting fuel husk waste into briquettes. The study was conducted using burnt husk waste generated from the energy production process through husk burning in tofu manufacturing.

Assessing environmental impact in brass component companies through life cycle assessment: a case study of brass crafts smes

Sampurna Kuningan is a small and medium enterprises (SMEs) specializing in creating various brass metal handicraft products. They need to improve their efficiency in producing brass door handles within their manufacturing process. The issues mainly revolve around two tasks - dipping and refining processes. At the finishing stage, the chemical solution left from brass cleaning is improperly treated and disposed of in the sewer, wasting resources. This study’s primary objective is to evaluate the eco-efficiency index (EEI) value and propose improvement strategies to reduce the environmental impact caused by their production activities. The eco-efficiency measurement involves comparing the financial performance represented by the net value and the environmental performance measured as eco-cost. The eco-cost is calculated using a life cycle assessment through the Sima-Pro software. The results of the calculations indicate an EEI value of 2.22. The production process is both economically affordable and sustainable. However, there is a relatively high environmental impact during the finishing process. Improvement scenarios for this process include implementing water treatment or substituting finishing chemicals. Using citric acid for a brass door handle yields a significant average reduction in eco-cost, reaching approximately 50%.

Framework for Increasing Eco-efficiency in the Tofu Production Process: Circular Economy Approach

Abstract This research aims to design recommendations for improving the tofu production process in Sugihmanik Village. Over 30 tofu small medium enterprises (SMEs) generate solid and liquid waste, which pollutes the river. An eco-efficiency strategy was implemented and began by identifying the tofu production process. The life cycle assessment (LCA) method and the SimaPro software were used to calculate eco-cost and eco-efficiency levels. Based on the calculations, the eco-cost value per batch is USD 10.76. If 30 batches are produced daily, the eco-cost value in one of the tofu SMEs is USD 9.10. Tofu production has an eco-efficiency index (EEI) value of 0.12. This value shows that tofu products are only affordable but have yet to be sustainable. The researchers then recommend using biogas from wastewater treatment to replace rice husks and corncobs. This study also develops a circular economy framework in the tofu production system. The output is expected to suppress the discharge of water and solid waste to increase the EEI value of the tofu production process in the future.

Sustainable analysis of Waste-to-Energy systems in cities by eco-efficiency assessment using DEA approach: A case study of Iran's municipalities

Municipal Solid Waste (MSW) management has become a pressing global issue due to population growth, urbanization, and changing consumption patterns, especially in developing countries. This study develops a comprehensive framework to evaluate the sustainability of MSW management systems. Also, the sustainability of Anaerobic Digestion (AD) and landfill systems with/without various Cogeneration of Heat and Power (CHP) technologies in different conditions using the framework in the municipalities of Iran. The eco-efficiency index, which considers environmental and economic aspects, is used to assess the systems sustainability. The Data Envelopment Analysis (DEA) method is applied to assess and rank the performance of the systems based on their eco-efficiency indices considering parameters such as energy production, costs, emissions, land occupation, water consumption, and employment. The results indicate that the landfill and AD systems with/without CHP have the highest priority for all provinces when the food, paper, and cardboard wastes entering the systems are at their maximum and minimum amounts. However, the systems without CHP have the lowest efficiency when the share of the wastes is 50%. Although the findings can help decision-makers in improving MSW management, there may be limitations to the research, such as data availability and assumptions made during the analysis.

Utilizing waste compost to improve the atmospheric CO2 capturing in the rice-wheat cropping system and energy-cum‑carbon credit auditing for a circular economy

The study aimed to manage industrial wastes and create a module for using compost from waste for crops cultivation to conserve energy, reduce fertilizer use and Greenhouse gas (GHG) emissions, and improve the atmospheric CO2 capturing in agriculture for a green economy. In the main-plot, the experiment's results using NS3 found 50.1 and 41.8 % more grain yield and total carbon dioxide (CO2) sequestration in the wheat-rice cropping sequence, respectively, compared to the NS0. Moreover, the treatment CW + TV in the sub-plot observed 24.0 and 20.3 % higher grain yield and total CO2 sequestration than B + PS. Based on interaction, the NS3× CW + TV resulted in a maximum total CO2 sequestration and C credit of 47.5 Mg ha−1 and US$ 1899 ha−1, respectively. Further, it was 27.9 % lower in carbon footprints (CFs) than NS1 × B + PS. Regarding another parameter, the treatment NS3 observed a 42.4 % more total energy output in the main-plot than that of NS0. Further, in the sub-plot, the treatment CW + TV produced 21.3 % more total energy output than B + PS. Energy use efficiency (EUE) and net energy return in the interaction of NS3× CW + TV were 20.5 and 138.8 % greater than the NS0 × B + PS, respectively. In the main-plot, the treatment NS3 obtained a maximum of 585.0 MJ US$−1 and US$ 0.24 MJ−1 for energy intensity in economic terms (EIET) and eco-efficiency index in terms of energy (EEIe), respectively. While in the sub-plot, the CW + TV was observed at a maximum of 571.52 MJ US$−1 and US$ 0.23 MJ−1 EIET and EEIe, respectively. The correlation and regression study showed a perfect positive correlation between grain yield and total C output. Moreover, a high positive correlation (0.75 to 1) was found with all other energy parameters for grain energy use efficiency (GEUE). The variability in the wheat-rice cropping sequence's energy profitability (EPr) was 53.7 % for human energy profitability (HEP). Based on principal component analysis (PCA), the eigenvalues of the first two principal components (PCs) had been greater than two, explaining 78.4 and 13.7 % of the variability. The experiment hypothesis was to develop a reliable technology for safely using industrial waste compost, minimizing energy consumption and CO2 emissions by reducing chemical fertilizer input in agriculture soils.

Food production potential and environmental sustainability of different integrated farming system models in northwest India

Accelerated energy use, negative environmental outcomes, and poor economic returns questioned the sustainability of contemporary agricultural production systems globally. The task is much more daunting in the northwestern part of India where the over exploitation of natural resources is a major concern for sustainable agricultural planning. An integrated farming system (IFS) encompasses various enterprises such as crops, dairy, poultry, and fisheries can offer a myriad of benefits in terms of enhanced farm productivity, profitability, and environmental sustainability. Hence, the study hypothesized that the complementary interaction between the different enterprises would improve food production and reduce negative environmental outcomes. Therefore, production potential and environmental sustainability in terms of energy efficiency, greenhouse gas emissions, and eco-efficiency of nine IFS models, namely, crop enterprise (M2); crop + dairy (M3); crop + dairy + fishery (M4); crop + dairy + fishery + poultry (M5); crop + dairy + fishery + poultry + duckery (M6); crop + dairy + fishery + poultry + duckery + apiary (M7); crop + dairy + fishery + poultry + duckery + apiary + boundary plantation (M8); crop + dairy + fishery + poultry + duckery + apiary + boundary plantation + biogas unit (M9); crop + dairy + fishery + poultry + duckery + apiary + boundary plantation + biogas unit + vermicompost (M10), were compared with the rice–wheat system (M1; the existing system). All the IFS models were tested between 2018 and 2021. The results revealed that the highest food production (61.5 Mg ha−1) was recorded under M10 followed by M9 (59.9 Mg ha−1). Concerning environmental sustainability, the combination of crop + dairy + fishery + poultry + duckery + apiary + boundary plantation + biogas unit + vermicompost (M10) recorded considerably higher energy output (517.6 × 103MJ ha−1), net energy gain (488.5 × 103MJ ha−1), energy ratio (17.8), and energy profitability (16.8 MJ MJ−1) followed by M9. Furthermore, the M10 had the lowest greenhouse gas (GHG) intensity (0.164 kg CO2eq per kg food production). However, M9 had the highest eco-efficiency index (44.1 INR per kg GHG emission) followed by M10. Hence, an appropriate combination of diversified and complementary enterprises in a form of IFS model is a productive and environmentally robust approach for sustainable food production in the northwestern part of India.

Conservation tillage and diversified cropping enhance system productivity and eco-efficiency and reduce greenhouse gas intensity in organic farming

Environmental pollution, resource dwindling, and soil degradation questioned the sustainability of contemporary agricultural production systems. Organic farming is advocated as a sustainable solution for ensuring food security without compromising environmental sustainability. However, poor farm productivity quizzed the sustainability of organic production systems. Hence, a field study was carried out in the Sikkim region of the Indian Himalayas to assess the efficacy of conservation-effective tilling and diversified cropping on system productivity, profitability, environmental quality, and soil nutrient balance in organic farming. Three tillage systems, namely, (i) conventional tillage (CT), (ii) reduced tillage (RT), and (iii) zero tillage (ZT), and four maize based diversified cropping systems (maize–black gram–toria, maize–black gram–buckwheat, maize–rajmash–toria, and maize–rajmash–buckwheat) were tested using a three times replicated split-plot design. The ZT system recorded 13.5 and 3.5% higher system productivity over CT and RT, respectively. Of the four diversified cropping systems, the maize–rajmash–buckwheat system recorded the maximum system productivity (13.99 Mg ha−1) and net returns (3,141 US$ ha−1) followed by the maize–black gram–buckwheat system. Among the tillage practices, ZT recorded the significantly high eco-efficiency index (EEI; 1.55 US$ per kg CO2-eq emission) and the lowest greenhouse gas intensity (GHGI; 0.15 kg CO2-eq per kg production). Of the diversified cropping systems, the maize-rajmash-buckwheat registered the lowest GHGI (0.14 CO2-eq per kg production) and the highest EEI (1.47 US$ per kg CO2-eq emission). Concerning soil nutrient balance, after three cropping cycles, the soil under ZT recorded significantly higher available N (340.0 kg ha−1), P (16.6 kg ha−1), and K (337.3 kg ha−1) over the CT system at 0–10 cm soil depth. Similarly, the soil under the maize–black gram–buckwheat system had the maximum bio-available NPK. Thus, the study suggests that the cultivation of the maize–black gram/rajmash–buckwheat systems under ZT and/or RT would increase farm productivity, profitability, and soil fertility with minimum GHGI in organic farming under the Eastern Himalayan region of India.

Environmental and economic sustainability of fresh-cut and pre-cooked vegetables

Due to the growing awareness about the environmental and economic sustainability of food products, the present research aims to evaluate the sustainability of fresh-cut and pre-cooked vegetables, a niche market with growing demand. An analysis was carried out using a detailed material, energy, and economic inventory based on a commercial food processing plant located in northeast Spain. The environmental sustainability was determined using process-based environmental life cycle assessment (E-LCA), applying a cradle-to-market approach, and using the EF3.0 impact assessment methodology to quantify impacts on five midpoint categories (climate change, photochemical ozone formation, acidification, freshwater eutrophication, and fossil resource use) and an aggregated single score. Additionally, an environmental life cycle costing (E-LCC) was performed. The pre-cooked vegetable products showed a higher environmental footprint than the fresh-cut products in all the impact categories (between 14.0 % and 39.9 %) and involved higher life cycle costs (15.2 %), due to the increased demand for ingredients, packaging materials, and electricity consumption per FU (kg of product). The carbon footprint (CF) and the cost for the fresh-cut products were 0.72 kg CO2 eq/kg and 2.62 €/kg, respectively, compared to 0.86 kg CO2/kg and 3.02 €/kg for the pre-cooked vegetables. The environmental profiles of both products were rather similar, with a dominance of the Upstream stage (production of ingredients and packaging materials), followed by the Core stage (mainly due to electricity consumed during vegetable processing). The relevance of the Core stage is amplified in the economic analysis due to the incorporation of certain processes which were not included in the process-based E-LCA (e.g., labour, capital, insurance, maintenance costs, etc.). To integrate the economic and environmental analyses, an eco-efficiency index was calculated that describes the carbon emissions per unit of monetary cost, resulting in 0.27 kg CO2eq/€ for the fresh-cut and 0.28 kg CO2 eq/€ for the pre-cooked vegetables.

Impact of Environmental Economic Transformation Based on Sustainable Development on Financial Eco-Efficiency

The production and life of human beings are inseparable from the natural environment, and the current economic transformation is based on the sustainable development of the environment. However, the current environmental economic transformation lacks a corresponding evaluation model, so this paper aimed to explore the path of environmental economic transformation and analyze the impact of environmental economic transformation on financial eco-efficiency. Aiming at the transformation of environmental economy, this paper analyzed the relationship between the environmental quality and the transformation path and made a detailed analysis of the dynamic and static transformation process. After understanding the path of environmental economic transformation, this paper established a model to analyze the impact of eco-efficiency. In terms of indicators, this paper selected four indicators of environmental economic transformation: return on assets, gross margin of sales, period expense rate, and total asset turnover. Through data analysis, this paper discussed the impact of these four indicators on financial eco-efficiency. The experimental results show that the comprehensive coefficient of environmental and economic transformation indicators is 1.325 (p < 0.001). This shows that the environmental economic transformation has a significant positive correlation with the financial eco-efficiency, that is to say, a good environmental economic transformation can increase the financial eco-efficiency index.

Spatial differentiation and influencing factors of land eco-efficiency based on low carbon perspective: A case of 287 prefecture-level cities in China

The spatio-temporal evolution and influencing mechanism of land ecological efficiency (abbrev. eco-efficiency) are key to achieving optimal land eco-efficiency and ensuring high-quality economic growth. Therefore, based on 287 cities at prefecture-level and above in China, we constructed an efficiency measurement index system by using resource-capital-labor as the input index, economic-resource-social-ecological benefits as the desirable output and carbon emissions as the undesirable output. Besides, Jenks method, Exploratory Spatial Data Analysis (abbrev. ESDA), Trend Analysis and Standard Deviation Elliptic (abbrev. SDE) model were conducted to delve into the spatio-temporal pattern and influencing factors of land eco-efficiency from 2005 to 2019. The results are as follows: (1) under carbon emission constraints, the average values of land eco-efficiency index were showing a rising trend at first and a falling trend thereafter. Spatially, the difference went from large to small in the western, eastern, northeast and central China. (2) The high-efficiency areas were concentrated around Chongqing and gradually extended. The general-efficiency areas were mainly distributed in the Pearl River Delta and urban agglomerations around the middle reaches of the Yangtze River. The low-efficiency areas were widely distributed in the central China. In the trend analysis, the spatial gradient pattern gradually evolved from “flat” to “high in the west, low in the east” in the east-west direction, and from “flat” to a gentle “U-shape” pattern in the north-south direction. (3) The spatial autocorrelation changed from negative to positive and the spatial agglomeration gradually changed to a positive correlation. The main significant correlation types were between High-High (abbrev. HH) areas and Low-Low (abbrev. LL) areas. (4) The standard deviation ellipse of land eco-efficiency always showed the trend of “northeast-southwest”, and the center of gravity moved significantly along Xiangyang-Nanyang-Luohe-Nanyang. In the future, it will continue to integrate the analysis of the relationship between factor input-output, carbon emissions and ecol-efficiency from different perspectives, with a view to providing support for achieving high-quality regional development.

Spatial-Temporal Evolution and Convergence Characteristics of Agricultural Eco-Efficiency in China from a Low-Carbon Perspective

While agriculture plays an essential role in food security, it is also one of the largest emitters of carbon emissions. China’s carbon neutrality and carbon peaking goals mean that China’s agriculture is also going through a low-carbon transition. To analyze the spatiotemporal heterogeneity and convergence of China’s agricultural eco-efficiency (AEE), this study used a combined super-efficient slacks-based measure (SBM), global Malmquist–Luenberger index (GML), kernel density estimation, Moran index, and convergence model on panel data from 2005 to 2020 and from 31 Chinese provinces. An innovative eco-efficiency index evaluation system was constructed from a low-carbon perspective that integrated agricultural carbon sinks and carbon emissions. The results revealed that the average AEE movement was U-shaped, but there were significant differences across regions and periods. The AEE demonstrated a gradual decreasing pattern of “northeast > eastern > western > central”, a declining trend during 2005–2010 and increasing trends during 2011–2020. The main reason for AEE growth was technological progress; however, technical efficiency only played a role in several provinces. The AEE in Chinese provinces was also found to have spatial autocorrelation characteristics dominated by high-high, low-low, and high-low clustering. A “catching-up effect” existed in the lagging AEE regions. Therefore, it is recommended to promote the integration of regional strategies and low-carbon development, build a low-carbon technology support system, and construct a national agricultural carbon trading center to facilitate agricultural low-carbon transformation.