Citation: Assirelli, A.; Santangelo, E.; Stagno, F.; Roccuzzo, G.; Musio, S.; Amaducci, S. Hemp Sowing Seed Production: Assessment of New Approaches in North-Italy. Sustainability 2022, 14, 17020. https://doi.org/10.3390/su142417020 Academic Editor: Kevin Murphy Received: 31 October 2022 Accepted: 14 December 2022 Published: 19 December 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). sustainability Article Hemp Sowing Seed Production: Assessment of New Approaches in North-Italy Alberto Assirelli 1, * , Enrico Santangelo 1 , Fiorella Stagno 2 , Giancarlo Roccuzzo 2 , Salvatore Musio 1 and Stefano Amaducci 3 1 Consiglio per La Ricerca in Agricoltura e L’analisi Dell’economia Agraria, Centro di Ingegneria e Trasformazioni Agroalimentari (CREA-IT), Via Della Pascolare 16, 00015 Monterotondo Scalo, Italy 2 Consiglio per la Ricerca in Agricoltura e L’analisi Dell’economia Agraria, Centro di Olivicoltura, Frutticoltura e Agrumicoltura, Corso Savoia 190, 95024 Acireale, Italy 3 Istituto di Agronomia e Coltivazioni Erbacee, Facoltà di Agraria, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29100 Piacenza, Italy * Correspondence: alberto.assirelli@crea.gov.it Abstract: Bottlenecks occur as the cultivated area increases and the inappropriate mechanization methods hinder the stable supply of seeds for hemp multiplication. Moreover, the seeds ripen scalarly, and a timely stabilization is required to impede a germinability reduction. The study coupled the delayed sowing of a non-specific hemp variety to a harvesting system allowing for the collection of seeds with other threshing fractions. The final goal was the identification of an innovative route integrating agronomic and mechanical aspects for the improvement of the supply chain of seed production. To this aim, harvesting trials were carried out on the variety Futura sowed at the end of June in North Italy and were collected with a combine equipped with a separator developed for the recovery of threshing residues. The shortening of the growth cycle did not affect the plant height (173 cm on average). The effective working time of the combine was 57% of the total working time and the field efficiency was 1.14 ha h −1 , a good performance considering that in our work the seeds was threshed simultaneously to the harvest operation. Seed losses were found to be mostly at the expense of the mowing and threshing system (sector B) but remained below 5%. The separation system allowed for the rescue of 492.20 kg ha −1 (DW basis) of high-value threshing residues. Keywords: mechanization; harvesting; grain loss; hemp 1. Introduction Hemp (Cannabis sativa L.) is a high-yielding multi-purpose crop historically cultivated mainly for fiber production [1–3]. In the last decade, after more than a half-century of ban from cultivation, the European hemp cultivated area has been increasing, encouraged by the positive impact on the environment, such as the low requirement for pesticides [4] and the increasing request of raw materials for the emerging bio-based economy [5]. Even so, the European hemp production chain is a niche economy, because of the missed constant upgrade in terms of variety selection, agronomic practices and harvesting techniques, which are required parameters for stable supplies of standardized raw materials. In recent years, new technologies for increasingly sophisticated machines and new hemp varieties led to new scenarios [6]. The choice of a hemp harvesting system strongly depends on its final use: fibers (long or short); non-textile uses (paper, panels, substrates) where the fiber length is irrelevant; seed; double use (fiber and seed). Weaknesses of the hemp production chain in Italy, including seed production, comprise the need for research on mechanization and the lack of a national production chain [7]. One of the main general issues concerns the high biomass yields, as well as the specific mechanical characteristics of the crop which determine a huge load to the machine components. The mechanical harvesting of hemp seeds has other specific peculiarities. Hemp is characterized by the Sustainability 2022, 14, 17020. https://doi.org/10.3390/su142417020 https://www.mdpi.com/journal/sustainability