Non-food crops on marginal land: a study case of Camelina sativa (L.) and Crambe abyssinica (Hochst) on medium to steep slope in northern Italy

The European MAGIC project (H2020) based its research activity on the concept that marginal land could be used to grow industrial crops. This strategy could help satisfying the demand for renewable feedstock, mitigate land use competition (iLUC risk) and diversify farmers’ income through the access to new markets. However, the assessment of several key aspects of this strategy still lacks. The present study was established with the aim to help filling the knowledge gaps about the cultivation of Camelina sativa and Crambe abyssinica in marginal land. For the first time, agronomic performances of these two industrial crops were assessed in two slope fields (mild and severe slope) in the Emilia Romagna region (Italy). Camelina and crambe were also compared with barley and sunflower by an index (break-even yield) that aimed to offer a preliminary assessing about the opportunity to cultivate, in a simplified economic framework, such industrial crops in marginal land. The study confirmed that camelina and crambe are suitable for growing in steep slope land, proving their adaptability to a wide range of environments. Under the mild slope condition, both crops showed the ability to maintain satisfactory yield across a broad range of plant populations, whereas under the severe slope condition the poor plant density was a limiting aspect to control weeds and to improve seed yields. Qualitative yield traits (seed oil content and fatty acid profile) of both crops were never negatively affected by the marginality. The negative profitability observed for all the tested crops under the severe marginal condition questioned not only the opportunity to cultivate camelina and crambe under such a land but even the tested food crops. At the opposite, the positive profitability of camelina under the mild slope makes its cultivation in such a condition a concrete choice to be further explored.