Abstract: Plant cultivation activities represent the widest form of environmental agression at global scale. Their sustainability influences the stability of natural ecosystems at local, regional and global level. In this context, the aim of this study is to assess the sustainability of arable land in ROSCI0123 Măcin Mountains using the Pimentel- Eulenstein model. The model takes into account as input data various parameters characterizing the agricultural activities in the whole area occupied by six administrative units (mechanization, chemical treatment, irrigation etc.), this way assesing the energy efficiency and sustainability of crop plants. The results show that the exploitation of arable land in ROSCI0123 Măcin Mountains is done unsustainably in terms of energy efficiency, leading to a medium risk of affecting the valuable environmental components. Under these conditions, improved farming management is a key component in the management of ROSCI0123 Măcin Mountains.