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  • Publication
    Reevaluation of energy use in wheat production in the United States
    (Wiley, 2006) ;
    Steinberg, Laura J. 
    Energy budgets for agricultural production can be used as building blocks for life‐cycle assessments that include agricultural products, and can also serve as a first step toward identifying crop production processes that benefit most from increased efficiency. A general trend toward increased energy efficiency in U.S. agriculture has been reported. For wheat cultivation, in particular, this study updates cradle‐to‐gate process analyses produced in the seventies and eighties. Input quantities were obtained from official U.S. statistics and other sources and multiplied by calculated or recently published energy coefficients. The total energy input into the production of a kilogram of average U.S. wheat grain is estimated to range from 3.1 to 4.9 MJ/kg, with a best estimate at 3.9 MJ/kg. The dominant contribution is energy embodied in nitrogen fertilizer at 47% of the total energy input, followed by diesel fuel (25%), and smaller contributions such as energy embodied in seed grain, gasoline, electricity, and phosphorus fertilizer. This distribution is reflected in the energy carrier mix, with natural gas dominating (57%), followed by diesel fuel (30%). High variability in energy coefficients masks potential gains in total energy efficiency as compared to earlier, similar U.S. studies. Estimates from an input‐output model for several input processes agree well with process analysis results, but the model's application can be limited by aggregation issues: Total energy inputs for generic food grain production were lower than wheat fertilizer inputs alone, possibly due to aggregation of diverse products into the food grain sector.
      42  1Scopus© Citations 60
  • Publication
    Value‐based bricolage: Resource mobilization in the circular economy
    Sascha P. Klein
    Patrick Spieth
    Circular‐born firms face resource constraints first, as they emphasize the use and reuse of materials as an opposite to the linear production system of taking, making, and disposing of resources, and second, due to systemic challenges like lack of scale and information on resources. Given these challenges, entrepreneurs need to find novel solutions for resource mobilization in the circular economy (CE). This study aims to identify how entrepreneurs mobilize resources to accomplish these challenges. With qualitative, multiple‐case study research in circular‐born firms developing a CE business model (CEBM), we identify four patterns of resource mobilization serving different purposes in the development of a CEBM. While three patterns—resource seeking, material bricolage, and ideational bricolage—are established concepts in entrepreneurship, we identify and conceptualize a fourth unique pattern in the CE: value‐based bricolage. By conceptualizing the activity domains of value‐based bricolage and examining the motivation and outcomes of each pattern in designing CEBMs, we provide new insights into how solutions to challenges concerning the use of resources in the CE enable circularity.
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