Cultivation of Crambe abyssinica non-food crop in Portugal for bioenergy purposes: agronomic and environmental assessment

Crambe abyssinica is a non-food crop referenced in the literature as having high potential for renewable energy production. A comprehensive study regarding cultivation of Crambe was developed considering agronomic aspects (plant density, irrigation and fertilization), climatic aspects (weather conditions) and environmental impacts (life cycle assessment). This is probably the first study carried out with this specie in Portugal aiming to evaluate its adaptability and the potential impacts caused by its cultivation. Crambe was cultivated during four growing seasons using seeds of FMS Brilhante cultivar with a germination rate of 84%. The seeds yields were 742 kg ha(-1); 119 kg ha(-1) and 95 kg ha(-1) for the first, second and third growing seasons, respectively, lower than that reported in Brazilian studies (989-1347 kg.ha(-1)). The fourth growing season did not produce seeds due to prevalence of cold weather. The seeds oil content varied between around 26% and 34%. The first growing season showed the best growing cycle, the results evidencing that weather conditions, namely temperature and soil's moisture, possibly influence not only seeds yield but also oil yield. Mild temperatures until flowering and high water availability allowed achieving good emergence rates on shorter periods (between 19-43 days). Life cycle assessment performed according ISO 14040:2006 showed that the impacts related to Crambe cultivation in extensive farming mode (with organic fertilization and small inputs of labor) are mainly related to the consumption of diesel and electricity used in the preparation of field for sowing and its irrigation. Overall, Crambe cultivation showed lower impact for climate change than that verified for others systems in extensive mode.