A sustainability framework for assessing studies about marginal lands for planting perennial energy crops

One of the issues with large-scale perennial energy crop production is increasing land use competition between ‘food and feed’ and ‘fuel’. A commonly suggested solution is to limit energy crop plantation to marginal lands. However, the concept and the methods used to assess marginal lands remain vague and inconsistent across bioenergy-related studies. We propose a sustainability-based framework to review and classify studies for marginal lands used for bioenergy crops. This framework innovatively puts the marginal land in a sustainability-based framework, showing the interaction of biophysical, socioeconomic, qualitative, and quantitative assessments. We found that current studies lack integration of biophysical and socioeconomic considerations in the marginal land analysis. They also lack qualitative approaches to assess marginal land. We suggest that future work should emphasize integrating biophysical, socioeconomic, quantitative, and qualitative analysis for sustainable marginal land identification and use.