Average Greenhouse Gas Emissions Research Articles

Can converting raw straw into biochar incorporation achieve both higher maize yield and lower greenhouse gas emissions intensity in drought-prone environment?

Converting raw straw into biochar is considered an effective strategy for soil carbon sequestration. However, it remains uncertain whether biochar is more environmentally friendly for achieving higher crop yield in comparison to raw straw in drought-prone regions. Here, a 5-year experiment with three treatments (no incorporation(CK), raw straw incorporation(SI) and straw-derived biochar incorporation(BI)) was conducted to examine the effects of SI and BI on soil physicochemical properties, grain yield (GY), and greenhouse gas (GHG) emissions. Results indicated both SI and BI increased soil water content (SWC), soil temperature (ST), soil porosity, field capacity, pH, total nitrogen and soil organic carbon (SOC) compared with CK. On average, seasonal soil CO2 emission increased significantly by 42.3% in SI and 16.8% in BI, respectively; seasonal N2O emission increased by 26.9% in SI, while decreased by 17.5% in BI. Particularly, the 5-year average GY was as high as 9.4 t ha-1 in BI, significantly higher than that of SI and CK. The 5-year average global warming potential (GWP) increased by 57.9% and 24.6% under SI and BI, respectively, compared with CK. As a result, the average GHG emission intensity (GHGI) increased by 32.0% in SI, whereas it declined by 8.9% in BI. Attribution analysis showed that the CO2 emission primary driven GHGI change under SI, contributing up to 76.4% to GHGI increase. Conversely, the GY increase primary driven GHGI change under BI, contributing to 55.0% GHGI decrease. Therefore, converting raw straw into biochar incorporation acts as an environment-friendly strategy for higher yield harvest.

Well‐to‐wheels analysis of greenhouse gas emissions for passenger vehicles in Middle East and North Africa

AbstractBattery electric vehicles (BEVs) are widely considered a pathway to achieve low carbon mobility. BEVs emit zero emissions from the tailpipe, but their life cycle carbon reduction compared to gasoline vehicles varies based on primary energy sources, electricity generation, and use efficiency. The Middle East and North Africa (MENA) region is an area rich in fossil fuels, meriting a detailed comparison between the emissions from BEV and other powertrains. We developed a MENA‐specific life cycle model that estimates well‐to‐wheel (WTW) greenhouse gas (GHG) emissions from passenger transport with internal combustion engine vehicles (ICEVs), hybrid electric vehicles (HEVs), plug‐in hybrid electric vehicles, and BEVs. MENA's average WTW GHG emissions for all supply chain steps including combustion emissions from vehicle operation are 767 g/kWh and 84 g CO2eq/MJ for electricity and gasoline, respectively, but are highly variable due to heterogeneity in upstream supply chains. The use of hybrid gasoline ICEVs provides the largest emission reduction opportunity for existing vehicle fleets in 9 of the 16 MENA countries. For these nine countries, replacing gasoline ICEVs with HEVs could, on average, reduce country‐level life cycle GHG emissions by 47%. There is a similar emission reduction opportunity for 14 of the 16 MENA countries when normalizing vehicle efficiencies irrespective of the powertrain shares and other trends in existing vehicle fleets. Future scenario analysis shows that BEVs would have the lowest WTW GHG emissions among all powertrains in most MENA countries only if significantly reduced electricity transmission losses and cleaner grid mix are realized, although a high cost of infrastructure developments is expected.

Sustainable management strategies for balancing crop yield, water use efficiency and greenhouse gas emissions

CONTEXTTo ensure food security in the face of climate change, it is crucial to use effective agricultural management practices that produce the triangular win-win for water, crops, and environments. OBJECTIVEThis study aimed to explore the sustainable management measures for balancing crop yield, water use efficiency (WUE) and greenhouse gas (GHG) emissions in China during 1981–2020. METHODSThe study selected the Beijing-Tianjin-Hebei (BTH) region of China as the research area, where there were sharp contradictions among water shortage, food security and polluted environment. Four irrigation treatments and four fertilization treatments were set referring to the local cultivated experiences. The daily dynamic changes in crop yield, WUE and GHG emissions were simulated by optimized Agricultural Production Systems sIMulator (APSIM) model. RESULTS AND CONCLUSIONSThe irrigations had positive impacts on crop yield and WUE in BTH region. The irrigation amount's rise caused a gradual augmentation in the total yield of winter wheat and summer maize from 1981 to 2020.The highest total yield was achieved under W4 irrigation treatment (320 mm water for winter wheat and 60 mm water for summer maize), with an annual mean of 24,579.2 kg·ha−1. The annual average WUE under the W3 irrigation treatment (240 mm water for winter wheat) was the highest, with an average of 13.9 kg·ha−1·mm−1. However, extensive fertilization exacerbated soil GHG emissions. The soil GHG emissions were found to be significant increase as the input amount of fertilization. The FI fertilization measure (no fertilization) was assessed to have the least impact on the environment, with an average GHG emissions of 0.4 Mg·CO2-eq·ha−1. The optimal goals of high yield, high WUE and low GHG emissions were achieved by choosing effective combination practices of water and nitrogen management. Overall, the W3 irrigation and F3 fertilization (180 kg/ha fertilizer for winter wheat and 120 kg/ha fertilizer for summer maize.) treatments had the maximum water-fertilizer production indexes in the BTH region. SIGNIFICANCEThis study highlights the importance of agricultural management measures for guaranteeing food security and environmental sustainability at the same time under climate change.

Spatiotemporal Trends of the Carbon Footprint of Sugar Production in China

Sugar is the main nutrient source of human beings and the basic raw material of the food industry. It is of great practical significance for China to find out the current situation and future trend of Greenhouse Gas (GHG) emissions from sugar production, and explore measures for reducing GHG emissions from sugar planting and processing. The IPCC GHG emissions accounting method is applied to analyze the carbon footprint of sugar production based on planting management and industrial development data, in which the GHG emissions per unit of sugar product are calculated and analyzed. According to Carbon Peak and Carbon Neutrality targets, the total GHG emissions of China's sugar industry in 2030 and 2060 are predicted and discussed. The results show that: (1) The average GHG emissions per unit yield of sugar show a downward trend from 2004 to 2021. The total GHG emissions of sugar production in China have reached 1319.9 × 104 t CO2eq in 2021, which has not yet reached its peak due to the growth of consumption demand. (2) The average GHG emissions per unit of Beet Sugar (1.477 tCO2eq/t) is higher than that of Cane Sugar (0.825 tCO2eq/t). It is more meaningful to enlarge the planting area of sugarcane than that of sugarbeet in the future. (3) Overall, in 2021 the GHG emissions of sugar production reached 0.91 tCO2eq/t in China, which would decline 15 %–87 % until 2030 and 2060. There is great potential for sugar production to reduce GHG emissions in the future.

Direct greenhouse gases from domestic wastewater treatment plant in Bandung Regency, West Java, Indonesia

Wastewater treatment contributes direct greenhouse gas (GHG) emissions in the atmosphere. The study aims to estimate the amount of methane (CH4) and carbon dioxide (CO2) emitted from domestic wastewater treatment plants (WWTP) in Bandung Regency throughout the years 2019-2022. Wastewater treatment processes in the WWTP consist of anaerobic, facultative, and maturation ponds. Data series of water quality from each process were collected on a monthly basis from years 2019 to 2022 to estimate direct emissions. Emission factors used in this study were derived from IPCC Guidelines and using the Tier 1 method. The highest GHG emission from WWTP Bojongsoang was about 513.44 tonCO2e in December 2021. The monthly average CO2e emissions from year to year increased about 40.12%. The average GHG emission from WWTP Bojongsoang from the year 2019 to 2022 respectively was about 81.33 tonCO2e/month, 135.21 tonCO2e/month, 229.26 tonCO2e/month, and 193.89 tonCO2e/month. Overall, the percentage of CO2e emission from anaerobic pond was about 93.57%, from facultative pond was about 4.86%, and from maturation pond was about 1.57%. The highest CO2e emissions occurred in the anaerobic pond along with the highest COD reduction also took place in the anaerobic pond.

Carbon footprint of hospital laundry: a life-cycle assessment

ObjectivesTo assess greenhouse gas (GHG) emissions from a regional hospital laundry unit, and model ways in which these can be reduced.DesignA cradle to grave process-based attributional life-cycle assessment.SettingA large hospital...

Carbon Footprint Assessment Based on Life Cycle Assessment of Biomass Power Plant

This research aims to study the carbon footprint based on the life cycle assessment of biomass power plants. Covering the acquisition of raw materials to the end of the production process in biomass power plants (cradle to grave: C2G). The study proposes constructive ways to reduce the carbon footprint of biomass power plants. Conducted research consisting of 3 phases: phase 1, the rubber plantation process; phase 2, the rubber wood processing plant; and phase 3, the biomass power plant. Assessment of carbon footprint: following the principle of life cycle assessment, the results of the carbon footprint assessment found that in Phase 1, the process of growing rubber trees throughout the life cycle calculated the carbon footprint of the sample group as average greenhouse gas emissions from fresh rubber wood and combined with the average greenhouse gas emissions from rubber wood timbers of 1.1186 kgCO2eq per day. In phase 2, rubber wood processing plants throughout the life cycle have average greenhouse gas emissions of 15,319.11 kgCO2eq per day. In phase 3, biomass power plants electricity capacity is 9.9 MW per day, and their greenhouse gas emissions are 44,753.60 kg CO2eq per day. The result found that greenhouse gas emissions from biomass power plants per 1 kWh accounted for a carbon dioxide equivalent of 4.52 kgCO2eq. Calculate the predictor factors affecting the amount of greenhouse gases in biomass power plants in raw score form as Y = 373.516 +.082 (raw material quantity), where Y is the greenhouse gas emission (kgCO2eq), using the forecast equation in standard score form. With Z =.983raw material quantity3, It was found that the quantity of raw materials had a positive correlation with the quantity of greenhouse gases at a statistical significance of .01 with a correlation coefficient of .983, which could explain the variability of the variables of the quantity of greenhouse gases with 96.70 percent accuracy.

Modified sectoral average greenhouse gas intensity for more accurate carbon risk analysis

Thanks to the existing data gaps, Monitoring climate-related financial risks is no easy task. Greenhouse gases play an important role in climate change; therefore, examining economic activities’ emissions can be a suitable way to analyse climate risks. However, relying only on activities’ average greenhouse gas emissions can be misleading, as substantial emitters can greatly divert the average values upwards. Modifying these sectoral average emissions by subtracting substantial emitters’ data results in a clearer picture of climate risk analysis. The modified sectoral average method, which primarily relies on data from the emission trading systems, treats companies under the EU Emissions Trading System (ETS) regulation separately. With this treatment, sectors with high emission values can experience a significant drop in sectoral average emission intensity compared to companies under ETS regulation. To use an already available but not applied data cluster is an affordable, easy-to-implement way to increase the accuracy of climate risk indicators. Results in Hungary show that implementing this information reduces sectoral average intensity for companies not under ETS regulation.

CO2, CH4, and N2O emissions from dredged material exposed to drying and zeolite addition under field and laboratory conditions

Dredging, the removal of sediment from water courses, is generally conducted to maintain their navigability and to improve water quality. Recent studies indicate that dredging can significantly reduce aquatic greenhouse gas (GHG) emissions. These studies, however, do not consider the potential emission from the dredged material (sludge) in the depot. In addition, it is unknown if and how GHG emissions from sludge depots can be reduced. Here we present spatiotemporal variations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes, as well as environmental variables from a sludge depot located in the Netherlands. Measurements were conducted monthly from the time the depot was filled until the sludge was dry and the depot was abolished. We also experimentally assessed the GHG mitigation potential of 1) keeping the sludge permanently inundated, and 2) the addition of different amounts of zeolite to increase sludge nitrogen binding capacity to reduce N2O emissions. In the depot and in the laboratory, a decrease in moisture content coincided with increased CO2 and N2O emissions while CH4 emissions decreased. We observed that permanent inundation reduced emissions (∼4 times less CO2-eq than in drying sludge). Adding zeolite lowered N2O fluxes from permanently inundated sludge but did not reduce total GHG emissions. During the depot's operational period, average CO2, CH4, and N2O fluxes were 5078, 27, and 5 mg m−2 d−1, respectively. GHG emissions from drying sludge occurred mainly in the form of CO2 (73% of the total CO2-eq emissions), with average GHG emission rates comparable to those reported for ditches and ponds. We estimate that approximately 14 tons of CO2-eq were emitted from the 0.011 km2 depot, which contained ∼20,000 m3 of sludge, during its entire operational period, and we argue that more studies are needed, considering different sludge origins, to expand our understanding of sludge depots.

GHG emissions and energy consumption of residential buildings-a systematic review and meta-analysis.

Residential buildings generate significant greenhouse gas (GHG) emissions and consume energy throughout their life cycle. In recent years, research on GHG emissions and energy consumption of buildings has developed rapidly in response to the growing climate change and energy crisis. Life cycle assessment (LCA) is an important method for evaluating the environmental impacts of the building sector. However, LCA studies of buildings show widely varying outcomes across the world. Besides, environmental impact assessment from a whole life cycle perspective has been undeveloped and slow. Our work presents a systematic review and meta-analysis of LCA studies on GHG emissions and energy consumption in the preuse, use, and demolition stages of residential buildings. We aim to examine the differences among the results of diverse case studies and demonstrate the spectrum of variations under contextual disparities. Results show that residential building emits about 2928kg GHG emission and consumes about 7430 kWh of energy per m2 of gross building area on average throughout the life cycle. Residential buildings have an average GHG emission of 84.81% in the use phase, followed by the preuse phase and demolition phase; the mean energy consumption in the use stage occupied the largest share of 84.52%, followed by preuse stage and demolition stage. GHG emissions and energy use vary significantly in different regions due to different building types, natural conditions, and lifestyles. Our study stresses the compelling requirement to slash GHG emissions and optimize energy consumption from residential buildings by use of low carbon building materials, energy structure adjustment, consumer behavior transformation, etc.

Assessing life-cycle GHG emissions of recycled paper products under imported solid waste ban in China: A case study

Changes of raw materials in China's recycled paper industry after the imported solid waste ban affect products' life-cycle greenhouse gas (GHG) emissions as well. This paper presented a case study of newsprint production with prior- and post-ban scenarios with life cycle assessment, including using imported waste paper (P0) and its three substitutions, i.e., virgin pulp (P1), domestic waste paper (P2), and imported recycled pulp (P3). The function unit is 1 ton of newsprint produced in China, and the study is conducted from cradle to grave which consists pulping and papermaking process, from raw material acquisition to manufacturing, with associated energy production and wastewater treatment, transport, and chemicals production. Our results showed that P1 holds the highest life-cycle GHG emission of 2724.91, followed by 2400.88 from P3. P2 has the lowest emission of 1619.27, only slightly lower than 1742.39 before the ban using route P0 (unit: kgCO2e/ton paper). Scenario analysis showed that current average life-cycle GHG emission for one ton of newsprint is 2049.33 kgCO2e, increased by 17.62 % due to the ban, while this number could be reduced to 12.22 % or even −0.79 % if switching from P1 to P3 and P2. Our study highlighted the importance of domestic waste paper as a promising way to reduce GHG emissions, which still has great potential to increase if with an enhanced waste paper recycling system in China.

Understanding the greenhouse gas emissions from China’s wastewater treatment plants: Based on life cycle assessment coupled with statistical data

Wastewater treatment plants (WWTPs) are significant contributors to energy consumption and anthropogenic greenhouse gas (GHG) emissions. For achieving carbon reduction in the wastewater treatment industry, the direct and indirect GHG emissions generated by WWTPs need to be understood from a holistic perspective. This study estimated GHG emissions from WWTPs at the country scale by integrating process-based life cycle assessment and statistical data. On-site data were collected from 17 WWTPs of various regions in China. Uncertainty analysis based on Monte Carlo was also performed, so as to provide more reliable results. The results show that life cycle GHG emissions generated from the wastewater treatment process vary from 0.29 kg CO2 eq/m3 to 1.18 kg CO2 eq/m3 based on 17 sample WWTPs. The key factors contributing to overall GHG emissions are also identified as carbon dioxide (fossil) and methane (fossil) to air mainly generated from electricity generation, and methane (biogenic) and nitrous oxide (biogenic) to air mainly generated from wastewater treatment. National average GHG emissions was evaluated with the value of 0.88 kg CO2 eq/m3, with on-site GHG emissions and off-site electricity-based GHG emissions accounting for 32% and 34%, respectively. The total GHG emissions generated from wastewater treatment are 56.46 billion kg CO2 eq in 2020, with Guangdong province having the dominant contribution. Policy suggestions (e.g., further adjusting the electricity grid toward a low carbon structure, improving technology to promote treatment efficiency and energy recovery) were highly recommended so that national GHG emissions of WWTPs can be reduced. In order to achieve the synergy of pollutant removal and GHG emission reduction, policy-making on wastewater treatment should be tailored to specific local conditions.

Private Vehicles Greenhouse Gas Emission Estimation at Street Level for Berlin Based on Open Data

As one of the major greenhouse gas (GHG) emitters that has not seen significant emission reductions in the previous decades, the transportation sector requires special attention from policymakers. Policy decisions, thereby need to be supported by traffic emission assessments. Estimations of traffic emissions often rely on huge amounts of actual traffic data whose availability is limited, hampering the transferability of the estimation approaches in time and space. Here, we propose a high-resolution estimation of traffic emissions, which is based entirely on open data, such as the road network and points of interest derived from OpenStreetMap (OSM). We estimated the annual average daily GHG emissions from individual motor traffic for the OSM road network in Berlin by combining the estimated Annual Average Daily Traffic Volume (AADTV) with respective emission factors. The AADTV was calculated by simulating car trips with the open routing engine Openrouteservice, weighted by activity functions based on statistics of the German Mobility Panel. Our estimated total annual GHG emissions were 7.3 million t CO2 equivalent. The highest emissions were estimated for the motorways and major roads connecting the city center with the outskirts. The application of the approach to Berlin showed that the method could reflect the traffic pattern. As the input data is freely available, the approach can be applied to other study areas within Germany with little additional effort.

Greenhouse Gas (CO2, CH4 & N2O) Emissions from Electricity Consumption in Private Sectors Universities of Karachi.

Increasing greenhouse gas (GHG) emissions is worsening the climate change and its impacts all over the world. Currently there are number of techniques to estimate the GHG emissions and their concentration in the atmosphere. This study estimates the GHG (carbon dioxide, methane and nitrous oxide) footprint based on the one-year average fossil fuel consumption in selected Private Sector Universities of Karachi. The annual average GHG emissions from all of the universities were calculated to be 2,183.84 Tons of carbon dioxide (CO2), 41.3544 kg of methane (CH4) and 7.2612 kg of nitrous oxide (N2O). The CO2 emission from individual universities were in the range of 800 to 5,000 tons per year. Similarly, the CH4 was emitted in the range of 15-90 kg per year. N2O emission from all the selected universities was found very low in the range 2-16 kg per annum. The study found that the overall rate of GHG emissions is rapidly increasing with an increase in fuel consumption resulted from high number of enrollments in selected universities. Study recommends the energy saving measures and the transition from fossil energy to renewable energy.

Comprehensive study on cascade hydropower stations in the lower reaches of Yalong river for power generation and ecology

According to the construction of the cascade hydropower stations in the lower reaches of the Yalong River and the ecological environment condition of the river, a medium and long-term optimal dispatching model with the goal of maximizing the power generation benefits of the cascade hydropower stations is established, and the dynamic programming method is used to optimize the solution, so as to obtain the ten-day average maximum power generation of cascade hydropower stations. According to the latest relevant research at home and abroad, it is found that during the power generation process of the hydropower station, the discharge will produce certain greenhouse gas (GHG) emissions during the delivery process. In this paper, the greenhouse gas emissions existing in the power generation process of cascade reservoirs are considered, and the typical values are selected to calculate the average greenhouse gas (mainly CO2) emissions from 2001 to 2018, twelve plants with strong carbon sequestration and oxygen release capacity and suitable for growing in the basin are selected, and the mitigation and improvement measures of greenhouse gas emissions around the reservoirs in the basin are given. A new research idea is provided for the Yalong River cascade reservoirs to focus on the power generation benefits while reducing the greenhouse gas emission situation to a certain extent.

Environmental data and facts in the semiconductor manufacturing industry: An unexpected high water and energy consumption situation

With the expansion of the semiconductor industry, determining the huge associated water and energy consumption and accomplishing sustainable development can be key issues for this industry. This study surveyed the sustainability reports of 28 semiconductor corporations and summarized their environmental stewardship information. Overall, the total water withdrawal in 2021 was 7.89 ​× ​108 ​m3, total energy consumption was 1.49 ​× ​1011 ​kWh, and total greenhouse gas (GHG) emissions were 7.15 ​× ​107 tons CO2 equivalent. The total Scope 1 and Scope 2 GHG emissions were 2.74 and 4.41 ​× ​107 ​t CO2 equivalent, respectively. Surface water intake, municipal water supply, groundwater withdrawal, third party supply, and external reclaimed water intake accounted for 47.0%, 35.3%, 8.5%, 5.8%, and 3.2% of total water use, respectively. Electricity, fossil fuel, renewable energy, and others accounted for 83.7%, 12.0%, 2.7%, and 1.7% of the total energy use. In 2021, average water use, energy consumption, and GHG emissions were calculated to be 8.22 ​L/cm2, 1.15 ​kWh/cm2, and 0.84 ​kg CO2 equivalent/cm2, respectively, based on announced data. Ultrapure water consumption was predicted to be 5.51 and 0.95 ​× ​108 ​m3 worldwide and for China, respectively. Effective sustainability strategies are supposed to be implemented to meet the considerable growth in water and energy consumption and GHG emissions for the semiconductor industry worldwide and in China.

Estimating the carbon footprint of household activities in Japan from the time-use perspective

The household sector is a major driver of energy consumption and greenhouse gas (GHG) emissions. However, most existing studies have only estimated households’ carbon footprint from their expenditures. Households’ daily activity time, a scarce resource that limits and determines their consumption behavior, has rarely been integrated into the estimation. Incorporating the daily time-use patterns should thus provide a more practical perspective for mitigation policies aiming at promoting sustainable household lifestyles. In this study, by linking household time-use data and expenditure data of Japan, the carbon footprint and the GHG intensity of time of 85 daily household activities constituting the 24 hours in a day are estimated. Compared to the maximal 20-activity disaggregation in existing studies, our detailed 85-category disaggregation of daily time enables unprecedented details on the discrepancies between the carbon footprint from daily activities, many of which have previous been treated as one activity. Results indicate significant carbon mitigation potential in activities with a high GHG intensity of time, such as cooking, bathing, and mobility-related and activities. Average daily GHG emissions were also found to be higher on weekends as time-use patterns shift from paid work to free-time activities, highlighting the need for mitigation strategies on a weekly scale.

Meeting sustainable aviation fuel policy targets through first generation corn biorefineries

This paper investigates options to produce low carbon and renewable aviation fuel through existing commercial first generation biorefineries, which could be strategic given the rapid growth of the electric vehicle market for personal mobility. We evaluate the environmental impact of retrofitting a first generation biorefinery to produce aviation fuel through chemical process simulation. The analysis investigates the potential for reducing greenhouse gas (GHG) emissions and displacing fossil fuel (petroleum-based jet kerosene) in the aviation fuel industry through using corn feedstocks in dry grind biorefineries to convert sugars to 1,4-dimethylcyclooctane (DMCO), which qualifies as renewable jet-A fuel blend and is infrastructure compatible. The average life cycle GHG emissions for a baseline case and a scenario with carbon capture and storage (CCS) of fermentative CO2 are 36 and 5 g CO2 e/MJ DMCO, respectively. Investment in CCS at the biorefinery and adoption of crop best management practices on farms are essential for mitigating the risks of induced land use change GHG emissions for existing corn biorefineries. DMCO as a low-carbon aviation fuel could be a strategic fuel product for retrofitting existing corn dry grind facilities. For aviation fuel supply, corn dry grind facilities could displace about 12 % of jet fuel demand in the near term, which would meet sustainable aviation fuel policy targets. We conclude that corn-to-DMCO shows promise for near-term low-carbon fuel markets in the aviation industry and as a bridge to developing biomass-based jet fuel in the future.

Impact of landscape design on the greenhouse gas emissions of shrub willow bioenergy buffers in a US Midwest corn‐production landscape

AbstractPrevious studies have evaluated the economics and ecosystem services of perennial bioenergy crops when replacing grain crops on marginal (environmentally critical and/or underproductive) lands. This study used life‐cycle analysis (LCA) to investigate the greenhouse gas (GHG) emissions of perennial crops when grown in targeted landscape positions and their impact in reducing nitrogen leaching. Specifically, LCA was performed to evaluate the GHG emissions of growing shrub willow on marginal lands in the Indian Creek watershed in Illinois to assess the sustainability of strategically planted willow buffer strips. Willow was grown as a short‐rotation woody crop with a 21‐year rotation under three scenarios including a business‐as‐usual (BAU) field‐scale production with nitrogen fertilizer application and two unfertilized subfield buffer scenarios – landscape single subfield (LSSF) or landscape multiple subfields (LMSF) – grown alongside cornfields to reduce nitrate leaching. Each scenario also considers three field sizes, 2.0, 10.1, and 40.5 ha. The average annual GHG emissions from willow production and depot transportation were 0.32–0.77 Mg‐CO2e ha−1 with the lowest emissions for the LSSF scenario and highest for the BAU. The GHG emissions for the LSSF and BAU scenarios are independent of field size, whereas LMSF emissions increase with increasing field size, 0.41 Mg‐CO2e ha−1 at 2.0 ha and 0.76 Mg‐CO2e ha−1 at 40.5 ha. Emission results were most sensitive to the willow yield, followed by fertilizer application rate (BAU only), harvest fuel consumption, and transportation distance. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd

Optimized tillage improves yield and energy efficiency while reducing carbon footprint in winter wheat-summer maize rotation systems

Conventional tillage consumes a lot of energy and produces a lot of greenhouse gases (GHGs), with quite limited contribution to food production. Optimizing tillage practices is an important measure to save energy, protect the environment and increase productivity. Based on this concept, a field experiment of two years duration (2019–2021) was performed to assess the impacts of various tillage techniques on grain yield, energy balance, carbon footprint (CF), and economic benefits of a winter wheat-summer maize rotation system in the Loess Plateau of China. The treatments included conventional tillage (CT), no-tillage (NT), ridge cultivation with no-tillage (RNT), and occasional tillage (OT). This study is the first to evaluates the economic and environmental benefits of OT and RNT in dry farming. The total annual average greenhouse gas emissions calculated through the life cycle assessment are 2869.2–3407.6 kg CO2-eq·ha−1, and the energy consumption and output are 28.2–37.7 GJ ha−1 and 575.2–659.0 GJ ha−1, respectively. The net ecosystem economic benefit is 26,206.6–34,787.4 CNY ha−1. Compared with CT, annual crop yields of RNT, OT and NT have increased by 13.5%, 15.4% and 4.0%, respectively, energy utilization efficiency has increased by 47.8%, 31.2% and 35.3%, and carbon footprint has been reduced by 79.3%, 46.2% and 73.2%, economic efficiency has increased by 32.7%, 29.8% and 19.6%, respectively. Despite reducing energy consumption and carbon footprint, NT has no significant impact on annual crop yields. Optimizing tillage practices (RNT and OT) can achieve higher economic and environmental benefits. The Z-score shows that RNT in dryland agroecosystems can be used as a promising tillage practice to boost crop productivity, energy efficiency and economic efficiency, reduce CF, and achieve sustainability. RNT can be selected as the recommended agricultural management measure suitable for areas with similar climatic patterns in the Loess Plateau.