Environmental life cycle assessment of grain maize production: An analysis of factors causing variability

Changes in the Water-Energy Coupling Relationship in Grain Production: A Case Study of the North China Plain

Water consumption and energy consumption are inevitable in grain production, but few studies have focused on the integrated assessment of these two indicators and their relationships. To address the research deficiency, taking the North China Plain (NCP) as a case study, this paper quantifies the changes in grain crop planting structure and the accompanying changes in irrigation water consumption (IWC) and energy consumption (EC) in the NCP. On this basis, the water-energy coupling index (CI) is constructed to analyze the water-energy coupling relationship in the context of grain crop planting structure change. The results revealed that the sown area of three of the four main grain crops in the NCP, namely winter wheat, summer maize, and rice, roughly increased in the south and decreased in the north, while the sown area of spring maize increased in most counties where it was planted in the NCP from 2000 to 2015. With the change of grain crop planting structure, IWC and EC of winter wheat in the NCP decreased by 19.87 × 10⁶ m³ and 16.78 × 10⁸ MJ, respectively, mainly distributed in the Beijing-Tianjin-Hebei region, while IWC and EC of other crops all increased. In terms of CI values, although that of spring maize increased, those of winter wheat, summer maize, and rice all decreased, and the overall CI values of grain production in the NCP decreased from 0.442 in 2000 to 0.438 in 2015, indicating that grain crop distribution has been optimized toward a less water- and energy-intensive and more sustainable layout in the NCP. This paper can add case and methodological support to the food-water-energy (FEW) nexus research and can also provide policy suggestions for regional crop optimization layout and conservation of both water and energy resources.

Environmental life cycle assessment of monosodium glutamate production in China: Based on the progress of cleaner production in recent ten years

China is the world's leading producer of the flavor-enhancer monosodium glutamate (MSG), which is mainly produced by maize starch fermentation. Four typical scenarios (Scenario 1-Scenario 4) of MSG production from 2008 to 2019 in China were established for life cycle environmental impact assessment. Values for five midpoint environmental impact categories [primary energy demand (PED), resource depletion-water use (WU), global warming potential (GWP), acidification potential (AP), and eutrophication potential (EP)] were calculated with eFootprint based on data collected in China. The environmental impacts of producing 1 t of MSG in China in terms of PED, WU, GWP, AP, and EP were 52,800 MJ, 169,000 kg, 4590 kg CO₂ eq, 42.1 kg SO₂ eq, and 6.35 kg PO₄^3- eq, respectively, in 2019. The life cycle of MSG from cradle to gate includes maize cultivation (high WU values), and the MSG production process (high PED, GWP, AP, and EP values). The normalization results of environmental impacts significantly decreased from S1 to S4 with the improvement in cleaner production in recent ten years. Sensitivity and uncertainty analyses identified steam for MSG production, irrigation water, and ammonia volatilization during maize growth as the three main factors affecting the environment. There were obvious differences in calculated environmental impacts depending on the maize cultivation data source; i.e., data from the Ecoinvent 3.1 database, or collected data for the maize-wheat rotation system in north China or the maize monoculture system in northeastern China. This demonstrates the importance of collecting local data rather than applying database from other world regions. Compared with the use of coal and natural gas, the use of biogas to produce steam had much lower PED, WU, and GWP. Which types of alternative energy to use and the replacement ratio should be based on the actual resource reserves in each region.

Inventory review and environmental evaluation of first- and second-generation sugars through life cycle assessment

In recent years, there has been a great movement towards the generation of knowledge related to the biorefinery concept. First-generation biorefineries bear the stigma of using arable land and edible crops for fuel instead of as sources of food and feed. However, second-generation biorefineries have not reached the level of full technical feasibility. Bearing in mind the objective of sugar production from sugar, starch, or lignocellulosic raw materials, the purpose of this study is to assess the environmental impact of first- and second-generation biorefineries, considering as an example for the comparative evaluation, the production of sugar fractions from crops (starch and sugar crops), and lignocellulosic biomass (hardwood and softwood). The characterization results were obtained using the ReCiPe 1.1 model, implemented through the SimaPro 9.0 software. Both production systems are inherently different and have strengths and weaknesses that must be carefully analyzed. The resulting environmental profile shows that the silviculture of wood contributes less to the environmental impact than cropping activities in most impact categories. In general, this study suggests that first-generation systems are burdened environmentally by the use of fertilizers, which have a significant impact on categories such as marine and freshwater eutrophication and terrestrial acidification, while second-generation systems are limited by the intensive processing steps needed for delignification, typically involving the use of chemicals and/or energy. LCA in early stages of the production of bio-based building blocks, rather than on the manufacture of biofuels or bioplastics, allows the precise identification of the environmental burdens that may be influencing the overall environmental profile of a biorefinery.

Modelling the Influence of Soil Properties on Crop Yields Using a Non-Linear NFIR Model and Laboratory Data

This paper introduces a new non-linear correlation analysis method based on a non-linear finite impulse response (NFIR) model to study and quantify the effects of ten soil properties on crop yield. Two versions of the NFIR model were implemented: NFIR-LN, accounting for both the linear and non-linear variability in the system, and NFIR-L, accounting for linear variability only. The performance of the NFIR models was compared with a non-linear random forest (RF) model, to predict oilseed rape (2013) and wheat (2014) yields in one field at Premslin, Germany. The ten soil properties were used as system inputs, whereas crop yield was the system output. Results demonstrated that the individual and total contribution of the soil properties on crop yield varied throughout the different cropping seasons, weather conditions, and crops. Both the NFIR-LN and RF models outperformed the NFIR-L model and explained up to 55.62% and 50.66% of the yield variation for years 2013 and 2014, respectively. The NFIR-LN and RF models performed equally during yield prediction, although the NFIR-LN model provided more consistent results through the two cropping seasons. Higher phosphorus and potassium contributions to the yield were calculated with the NFIR-LN model, suggesting this method outperforms the RF model.

Comparative analysis on environmental and economic performance of agricultural cooperatives and smallholder farmers: The case of grape production in Hebei, China

Agricultural modernization and intensification have been regarded as a significant way to support agricultural development and improve farm income in China. Agricultural cooperatives have played an important role in promoting the modernization and intensification of Chinese agricultural sector. Given the increasing concerns about environmental harm, however, it still remains unclear whether and the extent to which agricultural cooperatives contributes to reducing environmental impacts of agricultural production. Hence, this study performed an environmental evaluation using life cycle assessment for three different organization forms of grape production in Changli County, Hebei Province, China: smallholder farmers, farmer-owned cooperatives and investor-owned firm-led cooperatives. Then the results of life cycle assessment were monetarized and cost benefit analysis was used to evaluate the economic performance of these three organization forms of grape production. The results demonstrate that investor-owned firm-led cooperatives present an overall improvement in environmental and economic performance with the lowest weighted environmental index (integrating all impact categories into a single score), the highest net profit and the highest total net benefit. The results also show a difference in potential improvement in environmental impacts and economic returns between cooperatives and smallholder farmers. Additionally, the production and application of organic and chemical fertilizer and pesticide have been identified as major contributors to total environmental damage.

Comparative life cycle assessment of coffee jar lids made from biocomposites containing poly(lactic acid) and banana fiber

Composites containing bio-based materials, like banana fiber and poly(lactic acid) (PLA), are potential food-packaging materials. We carried out an environmental life cycle assessment (LCA) of coffee jar lids made from high density polyethylene (HDPE), PLA, and banana fiber to assess their environmental performance. We considered differences in the type of blend (content of PLA and banana fiber in the composite), origin of the banana fiber feedstock (considered as either biowaste or as a co-product from banana production) and banana fiber pretreatment conditions (either no pretreatment or pretreatment using chemicals). Irrespective of the scenario, a lid made from 40% banana fiber and equal amounts of HDPE and PLA performed significantly better in all 18 impact categories when compared to a lid made from 100% PLA. By contrast, the same lid performed significantly better in 3 impact categories only (climate change, photochemical oxidant formation and fossil depletion) when compared to a lid made from 100% HDPE. Thus, environmental performance of the biocomposite strongly depends on which polymer base is replaced by the banana fiber in the composite. Replacing PLA with banana fiber is generally expected to bring environmental benefits.

Life cycle assessment of maize cultivation and biomass utilization in northern Thailand

Maize, a major food source for the world, is a high-yield commodity crop, and one of five major crops in Thailand. Occupying about 33% of the Thai upland farmlands, maize farming has been growing tremendously especially in northern Thailand. However, after harvesting, open burning is widely used in order to get rid of maize cobs and husks in land preparation for the next period. The current maize farming practices have caused several problems to local communities as well as urban dwellers. The objectives of this research were: (i) to analyze the life cycle inventory of maize cultivation, maize cob pellet production and heavy fuel oil production in northern Thailand using IDEA v2.0 and ecoinvent v3.0 databases; (ii) to evaluate environmental impacts of maize cultivation, maize cob pellet production and heavy fuel oil production using A Global Scale Environmental Life Cycle Impact Assessment (LIME-3) with the results of weighting (Country-specific) based on monetary valuation of end-points. This study evaluated the life cycle environmental impacts of maize cultivation and continuing through biomass energy production from maize cob by comparing with heat production from heavy fuel oil in Mae Chaem and Chiang Dao districts in the north of Thailand by using two different databases, IDEA v2.0 and ecoinvent v3.0 with an endpoint-based life cycle impact assessment (LCIA) method (LIME-3). The system boundary of this study includes land preparation, planting, weeding, farming, harvesting, maize cob pellet production and heat production from maize cob pellet and heavy fuel oil. The units of analysis in this study are 1 kg of maize grain, 3.76E-03 MJ of biomass energy production from maize cob and 3.76E-03 MJ of heat production from heavy fuel oil, respectively. The data were obtained from field survey supplemented with the Thai National Life Cycle Inventory Database and other scientific publications. The results included the environmental impacts of maize cultivation and continuing through biomass energy production from maize cob by comparing with heat production from heavy fuel oil in Mae Chaem and Chiang Dao districts by using two different databases with LCIA method on the endpoint approaches (LIME-3). The total damage cost based on IDEA v2.0 life cycle inventory (LCI) database in Mae Chaem and Chiang Dao districts was about 4.64E-01 USD and 4.89E-01 USD, respectively. As regards ecoinvent v3.0 database, the total damage cost in Mae Chaem and Chiang Dao districts was about 5.37E-01USD and 5.99E-01 USD, respectively. It can be seen that the total damage cost using different inventory databases in Chiang Dao are slightly higher than Mae Chaem due to different input materials. The result of total cost using inventory data from ecoinvent v3.0 is slightly higher than IDEA v2.0 due to different inventory processes in each database. However, the results in this study demonstrated that the databases show similar trends in the assessment results. On the other hand, certain numerical differences between the databases at some points were found to be more substantial. The results of present study are particularly relevant to policy choices for improving or using the good practices for maize cultivation, which would reduce the environmental performance of maize production systems in the area. To address the air pollution issue from biomass open burning of agricultural residues in the study area, the government agencies in Thailand should be responsible for promoting better biomass management for the future.

Environmental sustainability of conventional and organic farming: Accounting for ecosystem services in life cycle assessment

Today, there is an ongoing debate about the environmental sustainability of the products of organic farming. To compare the performance of conventional and organic farming systems regarding environmental impact and productivity, the comprehensive environmental assessment tool 'life cycle assessment' can be used. The lower crop yields attained by organic systems compared to conventional farming systems might, however, outweigh the benefits of the use of more environmental-friendly practices when evaluating the environmental impact per product unit. Although these practices are beneficial for the environment, which is reflected in the delivery of a range of ecosystem services (ES), the focus is traditionally put only on the (harvested) product. Because the agricultural product involves actually a bundle of ES, the impact should be allocated among the whole output of an agricultural system. In this study, we propose an allocation procedure based on the capacity of agricultural systems to deliver ES to divide the environmental impact over all agricultural outputs (i.e. provisioning and other ES). Allocation factors are developed for conventional and organic arable farming systems. Applying these allocation factors, we demonstrate that for about half of the studied food products (including maize, potato), organic farming has clear environmental benefits in terms of resource consumption in comparison to conventional cultivation methods. This allocation approach allows a more complete comparison of the environmental sustainability of organically and conventionally produced food.

Introduction of a natural resource balance indicator to assess soil organic carbon management: Agricultural Biomass Productivity Benefit

The rising demand for feed and food has put an increasing pressure on agriculture, with agricultural intensification as a direct response. Notwithstanding the higher crop productivity, intensive agriculture management entails many adverse environmental impacts. Worldwide, soil organic carbon (SOC) decline is hereby considered as a main danger which affects soil fertility and productivity. The life cycle perspective helps to get a holistic overview when evaluating the environmental sustainability of agricultural systems, though the impact of farm management on soil quality aspects is often not integrated. In this paper, we introduce an indicator called Agricultural Biomass Productivity Benefit of SOC management (ABB_SOC), which, relying on natural resource consumption, enables to estimate the net effect of the efforts made to attain a better soil quality. Hereby the focus is put on SOC. First, we introduce a framework to describe the SOC trend due to farm management decisions. The extent to which remediation measures are required are used as a measure for the induced SOC losses. Next, ABB_SOC values are calculated as the balance between the natural resource consumption of the inputs (including remediation efforts) and the desired output of arable crop production systems. The models RothC and EU-Rotate_N are used to simulate the SOC evolution due to farm management and the response of the biomass productivity, respectively. The developed indicator is applied on several rotation systems in Flanders, comparing different remediation strategies. The indicator could be used as a base for a method to account for soil quality in life cycle analysis.

Modeling ecotoxicity impacts in vineyard production: Addressing spatial differentiation for copper fungicides

Application of plant protection products (PPP) is a fundamental practice for viticulture. Life Cycle Assessment (LCA) has proved to be a useful tool to assess the environmental performance of agricultural production, where including toxicity-related impacts for PPP use is still associated with methodological limitations, especially for inorganic (i.e. metal-based) pesticides. Downy mildew is one of the most severe diseases for vineyard production. For disease control, copper-based fungicides are the most effective and used PPP in both conventional and organic viticulture. This study aims to improve the toxicity-related characterization of copper-based fungicides (Cu) for LCA studies. Potential freshwater ecotoxicity impacts of 12 active ingredients used to control downy mildew in European vineyards were quantified and compared. Soil ecotoxicity impacts were calculated for specific soil chemistries and textures. To introduce spatial differentiation for Cu in freshwater and soil ecotoxicity characterization, we used 7 European water archetypes and a set of 15,034 non-calcareous vineyard soils for 4 agricultural scenarios. Cu ranked as the most impacting substance for potential freshwater ecotoxicity among the 12 studied active ingredients. With the inclusion of spatial differentiation, Cu toxicity potentials vary 3 orders of magnitude, making variation according to water archetypes potentially relevant. In the case of non-calcareous soils ecotoxicity characterization, the variability of Cu impacts in different receiving environments is about 2 orders of magnitude. Our results show that Cu potential toxicity depends mainly on its capacity to interact with the emission site, and the dynamics of this interaction (speciation). These results represent a better approximation to understand Cu potential toxicity impact profiles, assisting decision makers to better understand copper behavior concerning the receiving environment and therefore how restrictions on the use of copper-based fungicides should be considered in relation to the emission site.

The influence of fertiliser and pesticide emissions model on life cycle assessment of agricultural products: The case of Danish and Italian barley

Barley is an ancient crop and a great source of nutrients. It is the third largest agricultural commodity produced in Denmark and represents a relevant crop in Italy too. Due to the increasing customers awareness of sustainability issues, it has become essential to evaluate the environmental impact and the use of resources in food production and distribution systems. However, especially in agriculture, difficulties are encountered when emissions from fertilisers and pesticides need to be modelled, due to a variety of modelling options and their dependency on the availability of site-specific information. How to address these difficulties might affect the results reliability. Hence, this study aims to evaluate, using the life cycle assessment (LCA) methodology, the influence of different models for estimating emissions from fertilisers and pesticides on the environmental impacts of barley cultivation in Denmark and Italy. Two models for fertilisers and pesticides' emissions have been applied; these differ on the extent of data requirements and complexity of calculation algorithms, which might increase the results accuracy and robustness. The results show that the modelling options do affect the environmental impacts of barley production, in particular climate change, eutrophication categories, acidification and freshwater eco-toxicity. This study estimates that the variations for such categories range from 15% in the case of climate change to 89% in the case of marine eutrophication. These findings highlight the importance of the emission modelling options as well as the constraints of data requirements, critical aspects when a LCA study on agricultural products is carried out.