Cultivation of Cardoon, biomass species for green chemistry, with a circular economy approach

Since the early 2000s, CNR ISAFOM has been involved in different research activities aimed at cultivating the cardoon (Cynara cardunculus L.) as a new biomass crop. While in the first years of activity the research objective was aimed almost exclusively to energy production (1), in the last 6/8 years, the interest has focused on the potentiality of this species for the realization of new cultivation systems with low input intended to produce biomass, grains and roots for green chemistry in marginal areas of the Mediterranean environment applying a Bio economy criterion. The cornerstone of these researches, carried out with the support of several projects in collaboration with important industries in the sector, is represented by the possibility that the products obtained from the entire plant can be used for the realization of a model of Biorefinery compatible with the territory applying a circular economy approach, respecting the use of natural resources. The cultivation of the thistle allows to have considerable advantages from the point of view of the use of resources thanks to the fact that its production cycle can be completed in the condition of dry farming. The useful products obtained from the thistle made up of oleaginous grain with a good protein content, lignocellulosic biomass, roots rich in inulin and the presence of bioactive molecules in almost all the components of the biomass, allow its full exploitation to support different production sectors. Among the main sectors interested in this species we mention the bio-plastics supply chains to produce mulching cloths and bio-chemicals to produce various products including bio-lubricants, bio-herbicides, in addition to the production of protein meal for animal husbandry that represent an interesting co-product with high added value (2). Many of these products are directly expendable in the agricultural sector with a circular economy approach. More specific research conducted at the CNR ISAFOM in Catania showed that the cultivation of cardoon destined for biorefining, takes advantage of the organic substance supplied with the distribution of Municipal Solid Waste (MSW) compost with a significant increase in the carbon stored in the soil (3). Lastly, it should not be forgotten that it is a multi-year crop that requires limitation of soil tillage and entirely covers the soil with its biomass during the rainy season, for which there are clear advantages linked to the mitigation of erosion phenomena in the internal hilly areas. This can represent an additional advantage in the presence of the intensification of extreme weather phenomena induced by climate change. The results of the research conducted allow us to say that it is possible to build on the thistle, a virtuous and realistic cultivation system, able to maximize the agricultural crops through a sustainable use of resources respecting the environment, to create innovative products consistent with the development of an eco-compatible bioeconomy.