The opportunities and potential of camelina in marginal land in Europe

The European bioeconomy is steadily driving an industrial, economic, and social growth looking for sustainable biobased feedstocks able to replace fossil-based materials. In this scenario, there is an urgent and increasing need to produce locally industrial crops, with multiple applications and broad suitability to different pedo-climates. Furthermore, the actual EU legislation imposes to produce industrial crops not competing with food ones, and one possibility is to grow them on marginal land. Among others, camelina [Camelina sativa (L.) Crantz] has been identified as one of the most suitable options for marginal land in Europe, but so far there is a lack of studies conducted in such conditions able to provide reliable production data, on which it will be possible to build plausible business plans. At this scope different field trials have been established in four European countries, i.e., Italy, Greece, Germany, and Poland, in multiple growing seasons from 2018 to 2021, under different types of marginality. In details, in Italy camelina was tested under steep slopes (25% and 15%), in Greece in a soil with low fertility (pH < 5.5) and adverse terrain conditions (steep slope >12%); in Germany in a soil with limitations in rooting, i.e., rooting depth < 30 cm + stoniness > 15%, and in Poland in two sites one with sand > 40%, and the other with clay > 50% of the texture. Camelina was grown with an autumn cycle in Italy and Greece, and with a spring one in Germany and Poland. Camelina production was impacted by the marginal land, seed yield was on average 0.94 Mg DM ha(-1), ranging from 0.38 Mg DM ha(-1) for camelina sown in spring in Poland in the sandy soil, up to 1.93 Mg DM ha(-1) for camelina sown in autumn in Italy on a 15% slope. Camelina completely failed only in one growing season in the clay soil in Poland, in relation to extreme weed pressure, while in all the other situations it was able to produce seed. Seed quality, that was surveyed only in Italy and Poland, was not negatively impacted by marginality, demonstrating its capacity to cope with harsh growing conditions. Growing camelina in southern European marginal land, in autumn sowing, seemed the most conservative and safe strategy to achieve profitable yields. In terms of agronomic management, the most important choices to optimize the crop in marginal land resulted: weed management, N fertilization, and the harvesting phase.