Benchmarking environmental and operational parameters through eco-efficiency criteria for dairy farms

https://doi.org/10.1016/j.scitotenv.2011.02.013Get rights and content

Abstract

Life Cycle Assessment (LCA) is often used for the environmental evaluation of agri-food systems due to its holistic perspective. In particular, the assessment of milk production at farm level requires the evaluation of multiple dairy farms to guarantee the representativeness of the study when a regional perspective is adopted. This article shows the joint implementation of LCA and Data Envelopment Analysis (DEA) in order to avoid the formulation of an average farm, therefore preventing standard deviations associated with the use of average inventory data while attaining the characterization and benchmarking of the operational and environmental performance of dairy farms. Within this framework, 72 farms located in Galicia (NW Spain) were subject to an LCA + DEA study which led to identify those farms with an efficient operation. Furthermore, target input consumption levels were benchmarked for each inefficient farm, and the corresponding target environmental impacts were calculated so that eco-efficiency criteria were verified. Thus, average reductions of up to 38% were found for input consumption levels, leading to impact reductions above 20% for every environmental impact category. Finally, the economic savings arising from efficient farming practices were also estimated. Economic savings of up to 0.13 € per liter of raw milk were calculated, which means extra profits of up to 40% of the final raw milk price.

Research highlights

► Computation of operational and environmental benchmarks for dairy farming. ► Operational reductions of up to 38%, leading to impact reductions above 20%. ► Lack of a consistent pattern linking operational efficiency to specific parameters. ► Quantification of the economic savings related to the move towards efficiency. ► Validation of LCA + DEA methodology.

Introduction

The recognition of the food sector as a relevant source of environmental impact demands the evaluation of food production systems in a comprehensive way (Garnett, 2008, Mattsson and Sonesson, 2003). In particular, livestock-related systems are considered a major environmental issue (Garnett, 2009, Steinfeld et al., 2006). In this context, Life Cycle Assessment (LCA) has been widely used to evaluate the environmental impact of livestock products (de Vries and de Boer, 2010, IDF, 2009). Pork, chicken, beef, milk and eggs are among the most frequently assessed food products.

LCA is an internationally standardized methodology (ISO, 2006a, ISO, 2006b) to assess the environmental aspects and potential impacts associated with a product by means of (i) the compilation of an inventory of relevant inputs and outputs of a product system, (ii) the evaluation of the potential environmental impacts linked to those inputs and outputs, and (iii) the interpretation of the results of the inventory analysis and impact assessment phases in relation to the objectives of the study.

To date, several LCA studies have focused on the environmental performance of conventional and organic milk production systems at farm level. The number of farms assessed in each study is highly variable ranging from only 1 (Cederberg and Mattsson, 2000) to 119 dairy farms (Thomassen et al., 2009). On the one hand, studies dealing with a short number of farms acknowledge the need of more reliable inventories for the dairy farming stage if a global view of the dairy farming sector is pursued (Hospido et al., 2003). On the other hand, when managing multiple farms, the common procedure relies either on the definition of average inventory data (Basset-Mens et al., 2009a, Casey and Holden, 2005a) or on the report of average environmental impacts (Thomassen et al., 2009), sometimes making a rough distinction according to production rate ranges (Cederberg and Flysjö, 2004). In any case, the use of average values entails the handling of standard deviations and, therefore, data quality concerns (Reap et al., 2008a, Weidema and Wesnaes, 1996). In this respect, data variability and uncertainty constitutes a challenging issue in the environmental assessment of agri-food products (Basset-Mens et al., 2009b).

In a scenario where multiple input/output data are available for multiple facilities, Vázquez-Rowe et al. (2010) recommend the use of a methodological approach based on the joint implementation of LCA and Data Envelopment Analysis (DEA), which is known as LCA + DEA methodology. DEA is a linear programming methodology used to quantify in an empirical manner the comparative productive efficiency of multiple similar entities (Cooper et al., 2007). Each homogenous entity whose input/output conversion undergoes assessment is named Decision Making Unit (DMU). LCA + DEA methodology synergically combines LCA and DEA in order to provide a tool for the operational and environmental assessment of multiple DMUs (Iribarren, 2010). This approach allows eco-efficiency verification while avoiding the use of average inventory data (Lozano et al., 2009, Lozano et al., 2010, Vázquez-Rowe et al., 2010, Vázquez-Rowe et al., in press).

In this article, the eco-efficiency concept is managed in accordance with the definition from the World Business Council for Sustainable Development. Hence, eco-efficiency refers to the delivery of competitively priced goods that satisfy human needs while progressively reducing environmental impacts of goods and resource intensity throughout the entire life cycle to a level at least in line with the Earth's estimated carrying capacity (Schmidheiny, 1992).

Iribarren et al. (2010) discussed a set of unexplored potentials of LCA + DEA methodology. Interestingly, the performance of super-efficiency analyses to identify best performing units from an operational perspective was highlighted along with the applicability of LCA + DEA methods to attain economic enhancement of LCA results, therefore improving the use of LCA to support decision making (Reap et al., 2008b).

This article uses LCA + DEA methodology with the aim of performing an eco-efficiency assessment of a high number of dairy farms. Additionally, a super-efficiency study is undertaken in order to suggest the best performing farms. Furthermore, the economic gains linked to the change from inefficient to efficient farming practices are also estimated.

Section snippets

Contextualization of the study

Galicia (NW Spain) accounts for around 13,000 dairy farms, with a total annual production over 2 million tonnes of raw milk. This region provides more than 37% of the Spanish dairy farming production (FEGA, 2010), and ca. 1.3% of the European milk production rate (FAO, 2009). This percentage is 0.3% when turning to a worldwide scale (FAO, 2009).

Galician dairy farms are characterized by a diversity of land use and production models, a variety of farm sizes, and considerable geographical

Inventory data

Data collection is of paramount importance in any LCA, DEA or LCA + DEA study. Indeed, data availability determines the feasibility of these analyses. Table 1 gathers the most relevant inventory data for the sample of 72 Galician dairy farms. Data refer to the annual operation of each farm and correspond to the allocated values for raw milk. As observed, raw milk production levels ranged from 69 to 1100 m3 per year, and a total of 32,000 m3 of raw milk are annually produced by the whole sample.

Environmental and operational performance of Galician dairy farming

In the present study, average current environmental impacts per liter of raw milk were 9.0 g SO2 eq for AP, 4.3 g PO43− eq for EP, 771.3 g CO2 eq for GWP, 0.9 m2a for LC and 3787.6 kJ eq for CED. These average values are in accordance with the range of results provided by previous LCA studies on dairy farming (de Vries and de Boer, 2010, IDF, 2009). Coefficients of variation ranged from 18% for GWP to 31% for LC, which stresses the convenience of avoiding the use of average inventory data by handling

Conclusions and perspectives

The application of a combined LCA and DEA approach provided valuable results to benchmark both operational and environmental parameters in dairy farming. Avoidance of standard deviation concerns, identification of best performers, quantification of economic savings and eco-efficiency verification were highlighted as the main advantages of LCA + DEA methodology when compared to the single use of LCA.

Operational efficiency scores were computed for a sample of 72 Galician dairy farms. On the one

Acknowledgements

The authors acknowledge Prof. Carlos J. Álvarez (Department of Agriltural and Forestry Engineering, University of Santiago de Compostela) for supplying valuable data on 50 Galician dairy farms. Dr. Iribarren and Dr. Hospido wish to thank the Spanish Ministry of Education (grant reference: AP2006-03904) and the Galician Government (contract reference: IPP-06-57), respectively, for financial support.

References (59)

  • S. Lozano et al.

    Environmental impact efficiency in mussel cultivation

    Resour Conserv Recy

    (2010)
  • M.A. Thomassen et al.

    Life cycle assessment of conventional and organic milk production in The Netherlands

    Agr Syst

    (2008)
  • M.A. Thomassen et al.

    Relating life cycle assessment indicators to gross value added for Dutch dairy farms

    Ecol Econ

    (2009)
  • K. Tone

    A slacks-based measure of efficiency in data envelopment analysis

    Eur J Oper Res

    (2001)
  • K. Tone

    A slacks-based measure of super-efficiency in data envelopment analysis

    Eur J Oper Res

    (2002)
  • B.P. Weidema et al.

    Data quality management for life cycle inventories — an example of using data quality indicators

    J Clean Prod

    (1996)
  • AEFA

    Spanish Association of Dehydrated Alfalfa Manufacturers

  • Agroinformacion

    Agroinformacion.com Agricultural Web Site

  • C.J. Álvarez-López et al.

    Typology, classification and characterization of farms for agricultural production planning

    Span J Agric Res

    (2008)
  • ANARPLA

    Spanish National Association of Plastic Recyclers

  • Bartrolí J. Avaluació ambiental del cicle del nitrogen a Catalunya: aplicació de l'anàlisi del flux de substàncies [in...
  • C. Basset-Mens et al.

    Uncertainty of global warming potential for milk production on a New Zealand farm and implications for decision making

    Int J Life Cycle Ass

    (2009)
  • CAG

    Guissona Feed & Food Corporation

  • J.W. Casey et al.

    The relationship between greenhouse gas emissions and the intensity of milk production in Ireland

    J Environ Qual

    (2005)
  • J. Castro et al.

    Nutrient management on Galician dairy farms

    Grassland Sci Eur

    (2006)
  • C. Cederberg et al.

    System expansion and allocation in Life Cycle Assessment of milk and beef production

    Int J Life Cycle Ass

    (2003)
  • C. Cederberg et al.

    Life cycle inventory of 23 dairy farms in south-western Sweden. SIK-Rapport Nr 728

    (2004)
  • W.W. Cooper et al.

    Data envelopment analysis: a comprehensive text with models, applications, references and DEA-solver software

    (2007)
  • D. Davies

    Improving silage quality and reducing CO2 emissions

    Silage Insights eNewsletter; spring 2008

    (2010)
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