The Impact of Field Size on the Environment and Energy Crop Production Efficiency for a Sustainable Indigenous Bioenergy Supply Chain in the Republic of Ireland

Abstract: This paper investigates, using the GIS platform, the potential impacts of meeting national bioenergy targets using only indigenous sources of feedstock on the habitats and carbon stores that exist within Ireland’s field boundaries. A survey of the Republic of Irelands field was conducted in order to estimate and map the size and geographic distribution of the Republic of Ireland’s field boundaries. The planting and harvesting costs associated with possible bioenergy crop production systems were determined using the relationship between the seasonal operating efficiency and the average field size. The results indicate that Ireland will need a large proportion of its current agricultural area (at least 16.5%) in order to its meet national bioenergy targets by 2020. The demand cannot be met by the current area that both has suitable soil type for growing the bioenergy crops and is large enough for the required operating efficiency. The results of this study indicate that implementing and meeting national bioenergy targets using only indigenous feedstock will likely impact the country’s field boundary resources negatively, as crop producers seek to improve production efficiency through field consolidation and field boundary removal. It was found that such boundary removal results in a loss of up to 6 tC/km² and 0.7 ha/km of previously permanent habitat where average field size is small. The impact of field consolidation on these resources reduces substantially as larger fields become consolidated.