Epsilon Archive for Student Projects

Abstract

In recent years various benefits of small scale, sustainable agriculture have been revealed. However such systems have rarely been assessed on a system level.
In this study emergy synthesis of a sustainable urban, food-producing plot was performed in order to assess the benefits and possible obstacles of such systems. Emergy evaluation was chosen due to its ability to show important interactions and evaluate different types of inputs in a common form (solar energy equivalents). Preliminary results of system indices (EIR: 1.4; EYR: 1.4; ELR: 2.66; EFR: 3.66; and ESI: 0.5) have shown relative low production efficiency in contrast to the amount of resources invested. In case of our model, labor represented the highest emergy contribution, an overwhelming 96 % of all input emergies.
And even though labor was done voluntarily, considering its supporting energy flows it is a non-renewable input resource. And while feedback (controlling) resources such as labor, or imported materials can accelerate system growth, extensive and long-term use of these resources is neither sustainable nor economical.
With respect to our output, first year results suggest that overwhelming portion of inputs resources were used to establish essential material and energy pathways and to build up environmental storages. Which suggests that self-organization requires considerable amount of resources and time.
System output in terms of yield generated has shown low result, with relatively high transformty values for co-products.
But while system yield has shown to be low, resource efficiency when all output are considered is high. Which implies an advantage in favor of sustainable urban food-producing systems because in contrast to conventional systems important resource inputs have shown to be stored and recycled. Such attributes mean greater sustainability, resilience and adaptation during an era of resource scarcity.