TECHNICAL EVALUATION OF MECHANICAL HARVESTING OF HEMP FIBRE

Hemp (Cannabis sativa L.) is considered a high-yielding crop providing raw materials for a large number of final products. Nowadays, the growing demand for more sustainable production systems brought a renewed interest in this crop. Despite the increase, the total hemp cultivated area is still relatively small when compared to most of the commodity crops in Europe. Moreover, the European hemp fibre market is stagnating while the seeds and secondary metabolites markets have had a relevant increase since 2010. To support the sustainable growth of the European hemp fibre market, the hemp stalks should be valorized with optimized agronomic technique and harvesting systems and with an adequate transformation of the raw materials. The study aim at evaluating the technical sustainability of a traditional mechanization system for fibre hemp harvesting that involves cutting, windrowing, baling and logistic chain for industrial process. Two hemp varieties were cultivated in two farms in Northern Italy and harvested at the full flowering stage. The hemp plants processed at the harvesting time resulted adequate in height for the mechanized harvesting and the subsequent baling without compromising crop productivity. The drying period in the field (around 40 days) was adequate to obtain stable and homogeneous balers. The crops were cutted into three sections using a tractor front mounted prototype machine patented by the University of Bologna (UNIBO. To complete the harvesting operations conventional windrowers and round balers, properly adjusted, were used. The working times were in line with other traditional agricultural crops and the qualitative aspects of the harvested hemp were adequate, without damage or clogging. The use of partially modified farm machines resulted in a decrease of the harvesting time with respect to specific machines and in line with other crops management (eg. haymaking).