Biofuels or not biofuels? The “Nexus Thinking” in land suitability analysis for energy crops

Biofuels play a key role in the decarbonization process of the transport sector contributing to climate change mitigation, energy security and rural development. However, the competition between energy and food in the use of resources, such as land, water and energy input, requires a robust and integrated methodological framework to promote a holistic sustainable resource management. Here, we propose a land suitability model for energy crops to analyze the dynamic interrelationships between land, water and energy, with the aim of promoting the efficient use of resources in the bioenergy context. The model was developed using multi-criteria decision analysis (MCDA) techniques in geographic information systems (GIS) integrated with the Water-Energy-Food nexus approach. The model was tested for the Basilicata region (southern Italy), comparing two energy crops: (i) rapeseed (Brassica napus L.) and (ii) cardoon (Cynara cardunculus L.). The application to the case study shows the importance of the land suitability analysis to identify the most suitable crop in a given territory, while the nexus spatial analysis for locating the suitable areas where a more efficient use of water, energy and land resources is reached. The results revealed also that the use of irrigation water would allow greater use efficiency of the other resources, such as land and energy, an aspect not to be underestimated in the energy, land and agricultural planning processes. The research work contributes to the debate on the sustainability of bioenergy, so that they can represent a sustainable solution to the energy issue and climate change.