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Purpose: A life cycle assessment (LCA) study was undertaken for the orchard stage of the NZ avocado value chain, to guide the development of indicators for facilitating continuous improvement in its environmental profile. Methods: The functional unit (FU) was 1 kg Hass avocados produced in NZ, up to the orchard gate. The baseline model assessed avocados produced in fully productive orchards, using input data collected from 49 orchards across 281 ha in the three main avocado growing regions of New Zealand. In addition, the non-productive and low production years of avocado orchards were assessed using data from four newly established avocado operations spread across 489 ha. Climate change, eutrophication, water use, freshwater ecotoxicity and terrestrial ecotoxicity results were calculated for each orchard. Finally, national scores were calculated for each impact category from the weighted averages of the individual orchard results in the baseline sample of the three studied regions. Results: There was significant variability between orchards in different input quantities, as well as impact scores. The impact assessment results showed that fuel use and fertiliser/soil conditioner production and use on orchard were consistently the main hotspots for all impact categories except water use, where impacts were generally dominated by indirect water use (irrespective of whether the orchards were irrigated or not). When considering the entire orchard lifespan, the commercially productive stage of the orchard life contributed the most to all impact category results. However, the impacts associated with 1 kg avocados, when allocated based on the total impacts across the orchard lifespan, were 13–26% higher than the baseline results which considered only the commercially productive years of the orchard life. Conclusion: The study identified the priority areas for focussed improvement efforts (in particular, fertiliser and fuel use for all impact categories, and agrichemical use for the ecotoxicity impacts). Second, the regional- and national-level impact scores obtained in this study can be used as benchmarks in indicator development to show growers their relative ranking in terms of environmental performance. When using the indicators and benchmarks in a monitoring scheme, consideration should be given to developing separate benchmarks (using area-based functional units) for young orchards. It will also be necessary to develop a better understanding of the reasons for the variability in inputs and impacts so that benchmarks can be tailored to account fairly and equitably for the variability between orchards and regions. [ABSTRACT FROM AUTHOR]

Purpose: The growing awareness of the importance of biodiversity in agroecosystems in increasing and ensuring the supply of biomass has led to heightened interest from governments and farmers in alternative crops. This article assesses one such alternative crop, cup plant (Silphium perfoliatum L.), in terms of the environmental aspects of cultivation for forage production. Many studies have previously focused on cup plant, but so far, this plant has not been assessed using the life cycle assessment (LCA) method. Materials and methods: This study compares the environmental load of cup plant with the most commonly grown silage crops in Central European conditions—maize—and with another common forage crop—lucerne using LCA. The system boundaries include all the processes from cradle to farm gate and both mass-based (1 ton of dry matter) and area-based (1 ha of monoculture) functional units were chosen for the purposes of this study. The results cover the impact categories related to the agricultural LCAs, and the ReCiPe Midpoint (H) characterization model was used for the data expression, by using SimaPro 9.0.0.40 software. Results: This study compares the cultivation of cup plant with the most commonly grown silage crop in Central European conditions—maize—and with another common forage crop—lucerne. The paper shows the potential of cup plant to replace conventional silage (maize and lucerne silage mix) with certain environmental savings in selected impact categories, and importantly, while still maintaining the same performance levels in dairy farming as with conventional silage, as already reported in previous publications. For the Czech Republic alone, this would, in practice, mean replacing up to 50,000 ha of silage maize and reducing the environmental load by about tens of percent or more within the various impact categories and years of cultivation. Conclusion: Cup plant can replace the yield and quality of silage maize, represents a lower environmental load per unit of production and unit of area and generally carries many other benefits. Thus, cup plant is a recommendable option for dairy farming. Given the recent experience and knowledge of the issue, the cup plant can be considered an effective alternative to conventional silage. [ABSTRACT FROM AUTHOR]

Purpose: Dissolving pulp production is mostly reliant on wood, which drastically depletes forest resources. To prevent the over-exploitation, the efforts were required by considering waste materials utilization. Therefore, a comprehensive assessment to account for environmental impacts was needed. The purpose of this research was to determine the environmental impact of empty fruit bunches (EFB) utilization from oil palms as a promising raw material substitute for wood in the production of dissolving pulp and furfural as co-product. Methods: The consequential life cycle assessment (cLCA) was performed by following the methodology in ISO 14040. Inventory for the input–output materials and energies for the proposed integrated dissolving pulp and furfural co-production process was evaluated based on laboratory-scale experiments. Meanwhile, the field survey as a reference for the existing practice in the conventional dissolving pulp industry was conducted. The SimaPro v8.0.5® software was used for the LCA calculation with the Centrum voor Milieuwetenschappen Leiden (CML) environmental impact assessment method. Several environmental impact categories, such as acidification, global warming, eutrophication, and human toxicity potential, were quantified. Results and discussion: This study examined three proposed scenarios for dissolving pulp and furfural co-production compared with the conventional dissolving pulp production. In the Scenario 1, 50% of the wood consumption was replaced by EFB and applied to acid prehydrolysis/soda cooking followed by ECF bleaching, with an additional process to co-produce furfural. In the Scenario 2, 100% of wood consumption was replaced by EFB, with the same cooking and bleaching parameters as those in Scenario 1. In the Scenario 3, 100% of wood consumption was replaced by EFB, and the acid was replaced by water in the prehydrolysis process to improve the total environmental performance with the same conditions as the previous scenarios. The Scenario 3 was the most promising scenario and had the lowest environmental impact. Conclusions: This research was conducted to propose EFB, which is environmentally sustainable and economically profitable, as a wood substitute in the co-production of dissolving pulp and furfural. The scenarios were proposed and compared with the existing practices. Based on the cLCA approach, this study recommended the EFB as a promising raw material and referred to Scenario 3 for the environmentally friendly system production. [ABSTRACT FROM AUTHOR]

Purpose: This review develops and applies a visualization method for understanding how chemical fertilizer inventory data, including greenhouse gas (GHG) emission factors and fossil fuel energy requirements, have been used in previous life cycle assessment (LCA) studies of oil palm and discusses how inconsistencies detected in previous studies can be decreased. Methods: As a visualization method for previous publications, a "family tree" was constructed using a directed graph (digraph) representation. Each node in the graph indicates an article, and an arrow from the source to a destination illustrates that the former article was cited in the latter article as a source of the background inventories. Bibliographical data extracted from the Web of Science were used for constructing the genealogy of fertilizer inventory use. Results and discussion: Several groups ("families") were identified through creation of the family tree. The most noticeable group was formed around the LCA database ecoinvent, which has the maximum number of out-flows (arrows from the node), suggesting a considerable influence of ecoinvent in the LCA of oil palm. In addition, temporal and spatial inconsistencies (outdated technological assumptions and substitutional use of European data) were detected in the visualization; therefore, the severity of the inconsistencies was discussed through an analysis of scenario uncertainty in nitrogen fertilizer production. The importance of devoting attention to fertilizer production technologies rather than simply to regional differences was clarified. Conclusions: This study demonstrates the usefulness of applying visualization methods in understanding the overall configuration of earlier studies. It is expected that the visualization and its implications constitute a way forward to good practices in inventory analysis. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to analyse the variability in the carbon footprint (CF) of organically and conventionally produced Valencian oranges (Spain), including both farming and post-harvest (PH) stages. At the same time, two issues regarding sample representativeness are addressed: how to determine confidence intervals from small samples and how to calculate the aggregated mean CF (and its variability) when the inventory is derived from different sources. Methods: The functional unit was 1 kg of oranges at a European distribution centre. Farming data come from a survey of two samples of organic and conventional farms; PH data come from one PH centre; and data on exportation to the main European markets were obtained from official secondary sources. To assess the variability of the farming subsystem, a bootstrap of the mean CF was performed. The variability of the PH subsystem was assessed through a Monte Carlo simulation and a subsequent subsampling bootstrap. A weighted discrete distribution of the CF of distribution and end-of-life (EoL) was built, which was also bootstrapped. The empirical distribution of the overall CF was obtained by summing all iterations of the three bootstrap procedures of the subsystems. Results and discussion: The CF of the baseline scenarios for conventional and organic production were 0.82 and 0.67 kg CO2 equivalent·kg orange−1, respectively; the difference between their values was due mainly to differences in the farming subsystem. Distribution and EoL was the subsystem contributing the most to the CF (59.3 and 75.7% of the total CF for conventional and organic oranges, respectively), followed by the farming subsystem (34.1 and 19.8% for conventional and organic oranges, respectively). The confidence intervals for the CF of oranges were 0.72–0.92 and 0.61–0.82 kg CO2 equivalent·kg orange−1 for conventional and organic oranges, respectively, and a significant difference was found between them. If organic production were to reach 50% of the total exported production, the CF would be reduced by 5.4–8.4%. Conclusions: The case study and the methods used show that bootstrap techniques can help to test for the existence of significant differences and estimate confidence intervals of the mean CF. Furthermore, these techniques allow several CF sources to be combined so as to estimate the uncertainty in the mean CF estimate. Assessing the variability in the mean CF (or in other environmental impacts) gives a more reliable measure of the mean impact. [ABSTRACT FROM AUTHOR]

Purpose: To promote eco-efficient sugarcane products, there is a need for life cycle assessment (LCA) methods that enable rapid assessment of the environmental implications of alternative agricultural practices. In response, a customised LCA method for sugarcane growing was developed and operationalized in the CaneLCA tool. The aim of the paper was to describe the CaneLCA method in detail and to test the effectiveness of the tool’s parameterisation for evaluating the environmental implications of cane growing practice alternatives.Methods: CaneLCA (Version 1.03) was developed over 6 years (2011-2017) in conjunction with the Australian sugarcane sector. The LCA process was customised for sugarcane growing by focusing on ‘cradle to farm gate’ operations and relevant impact categories, and by parameterising practice variables. To evaluate the effectiveness of the tool, we used it to assess a case study of actual practice changes in the Wet Tropics region of Australia, in terms of the scope of practice variables and environmental implications that can be accounted for.Results and discussion: The case study results generated by CaneLCA were consistent with those generated by past studies using LCA software. The parameterisation of practice variables allowed for all the practice changes represented in the case study to be assessed. It is suitable for evaluating such known practice alternatives, but less suited to evaluating very innovative practice alternatives, as it is constrained by the underlying algorithms and factors. Most of the environmental implications could be considered, except for effects on soil quality. This will be an area for future tool development to understand the full implications of agricultural practice change, along with the introduction of dynamic models to better estimate emissions.Conclusions: CaneLCA makes the LCA process more rapid for evaluating alternative sugarcane growing practices, thereby speeding up progress towards devising more eco-efficient sugarcane products. It provides a model that could be adapted for other sugarcane growing regions, and for other perennial cropping systems. The novelty of the method is the detailed parameterisation of practice variables so that a wide range of alternative practices can be evaluated. [ABSTRACT FROM AUTHOR]

Purpose: The carbon footprint of palm oil on mineral soils based on primary data from Malaysia was published in 2011, but a study for palm oil grown on peat is missing. The estimation of greenhouse gas emissions (GHG) of oil palm planted on peat in Malaysia was divided into three main components, namely GHG emissions from land use change, peat oxidation due to the establishment of oil palm plantations, and operations during cultivation and milling processes. The study collected comprehensive primary data for the latter and derived a best estimate for the other emissions to provide guidance for the most appropriate values and uncertainty range for oil palm planted on peat. The study highlights uncertainties and gaps in knowledge and provides recommendations for reducing GHG emissions for oil palm planted on peat.Methods: GHG emissions were estimated based on published data (LUC and peat oxidation) as well as from comprehensive primary data from operations at plantations mainly on peat in Sarawak and the palm oil mills for the period of 3 years. For this study, the data is partitioned into three case scenarios: (a) base case, where oil palm plantation is assumed from previously logged-over (PSF) with medium level of peat oxidation and 50% of the mills have the facilities to capture methane; (b) best-case scenario, where oil palm is assumed planted from previously degraded PSF or land with lowest estimation of peat oxidation and mills with methane capture facilities; and (c) worst-case scenario, where oil palm is assumed planted from previously virgin PSF with the highest estimation of peat oxidation and mills with methane capture facilities. GHG emissions from cultivation and milling stage were modeled using the System for Integrated Environmental Assessment of Product (SimaPro, version 8) with Ecoinvent database (ver 3).Results and discussion: Total GHG emissions for oil palm planted on peat for three scenarios arising from three main components range from 12.4 t CO2 eq ha−1 (best case) to 76.6 t CO2 eq ha−1 (worst case). These variations depend on C stock of previous vegetation, depth of drainage, length of time of drainage, amount of nitrogen fertilizer used, and use of methane capture facilities at the palm oil mills.Conclusions: GHG emissions for oil palm planted on peat can be reduced by developing plantations from degraded PSF or grassland with low carbon stock, with effective water management coupled with methane capture facilities at the mill and judicious application of nitrogen fertilizers using precision application according to requirement of the site based on diagnosis of nutrient requirement from soils and foliar analyses. In Malaysia, only 13% of the areas planted with oil palm are on the peat soil. Therefore, the overall GHG emission at the national level (13% planted on peat and 87% on mineral soils) can be further reduced by around 4.1 t CO2 eq ha−1 year−1. [ABSTRACT FROM AUTHOR]

Purpose: As highlighted in recent reviews, there is a need to harmonise the way life cycle assessment (LCA) of perennial crops is conducted. In most published LCA on perennial crops, the modelling of the agricultural production is based on data sets for just one productive year. This may be misleading since performance and impacts of the system may greatly vary year by year. The purposes of this study are to analyse how partial modelling of the perennial cycle through non-holistic data collection may affect LCA results and to make recommendations. Methods: Three modelling choices for the perennial crop cycle were tested in parallel in two contrasted LCA case studies: oil palm fruits from Indonesia, and small citrus from Morocco. Modelling choices tested were as follows: (i) a chronological modelling over the complete crop cycle of orchards, (ii) a 3-year average from the productive phase, and (iii) various single years from the productive phase. In both case studies, the system boundary was a cradle-to-farm gate with a functional unit of 1 kg fresh fruits. LCA midpoint impacts were calculated with ReCiPe 2008 in Simapro©V.7. We first analysed how inputs, yields and potential impacts varied over time. We then analysed process contributions in the baseline model, i.e. the chronological modelling, and finally compared LCA results for the various perennial modelling choices. Results and discussion: Agricultural practices, yields and impacts varied over the years especially during the first 3-9 years depending on the case study. In both case studies, the modelling choices to account or not for the whole perennial cycle drastically influenced LCA results. The differences could be explained by the inclusion or not of the yearly variability and the accounting or not of the immature phase, which contributed to 7-40 or 6.5-29 % of all impact categories for oil palm fruit and citrus, respectively. Conclusions: The chosen approach to model the perennial cycle influenced the final LCA results for two contrasted case studies and deserved specific attention. Although data availability may remain the limiting factor in most cases, assumptions can be made to interpolate or extrapolate some data sets or to consolidate data sets from chronosequences (i.e. modular modelling). In all cases, we suggest that the approach chosen to model the perennial cycle and the representativeness of associated collected data should be made transparent and discussed. Further research work is needed to improve the understanding and modelling of perennial crop functioning and LCA assessment. [ABSTRACT FROM AUTHOR]

Purpose: Palm oil systems generate substantial amounts of biomass residues which are, according to best agricultural practices, preferably returned back to plantation in order to maintain soil fertility. However, there are often variations in this practice. Differences in economic status and possible treatment options for biomass residues determine the preferences to perform life cycle assessment (LCA), leading to a divergence in results. Difficulties when comparing LCA results based on literature are not unusual. The objectives of this paper are to provide guidelines for methodological choices that enable a systematic comparison of diverse scenarios for the treatment and valuation of empty fruit bunches (EFBs) and to explore effects of the scenarios on the environmental performances of a palm oil system. Methods: Eleven scenarios were selected to address the possible EFB valuation and expanded boundaries with reference to the main palm oil system (EFBs applied as mulch, converted to compost or ethanol, treated in an incinerator, and sold as coproducts). The life cycle inventories were modeled based upon an Ecoinvent database. Solutions to multifunctional problems were suggested, including the application of system expansion, substitution, and partitioning, depending upon the nature of the scenarios. Results and discussion: Comparison among LCA results based on the same multifunctional units (crude palm oil + palm kernel oil + palm kernel cake) can be accomplished only in cases where additional coproducts were utilized internally. Based on the global warming impact, the mulch option was preferred. The effect of the avoided process of producing synthetic fertilizers and the assumption that all parts of mulch are available as soil nutrient dominantly determined the final result. These need further verification. This study also demonstrates that the status of EFB as waste or goods is influential on the final results if the EFB is employed externally but has no effect if it is utilized internally. Conclusions: The proposed guidelines provide methodological choices in terms of system boundary, functional unit, and solutions to multifunctional problems. The methods can be used to systematically compare LCA results of different treatment options and valuation of EFB. The preferred alternative for managing this biomass residue could improve environmental performances and orient toward best practices, such as those suggested by the Roundtable on Sustainable Palm Oil (RSPO). Further studies incorporating a site-specific case of palm oil systems would better illustrate the usefulness of the proposed guidelines. [ABSTRACT FROM AUTHOR]