Ievinsh, Gederts & Vikmane, Māra & Ķirse, Agnese & Karlsons, Andis. (2017). Effect of Vermicompost Extract and Vermicompost-Derived Humic Acids on Seed Germination and Seedling Growth of Hemp. Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.. 71. 10.1515/prolas-2017-0048.
Hemp (Cannabis sativa L.) cultivars grown for industrial use have recently emerged as a sustainable alternative source of industrial fibre and bioenergy, and is a highly valuable food and animal feed resource. The aim of the present study was to evaluate the effect of vermicompost extract, vermicompost mineral nutrient composition, and vermicompost-derived humic and fulvic acids on seed germination and growth of hemp seedlings. In general, separate application of all vermicompost components stimulated seed germination and hypocotyl and radicle growth, as well as increased chlorophyll concentration in cotyledons. Effective concentration range and the degree of stimulation varied significantly between the treatments. For practical purposes, application of vermicompost and vermicompost-derived extracts for stimulation of hemp growth could be useful at concentrations 5%, 0.05 mg·mL⁻¹ and 1%, for vermicompost extract, humic acids and fulvic acids, respectively.
Sustainable agricultural production, especially in organic agriculture, requires new means of fertilisation and plant protection. The use of variety of fertilizers and other products derived from organic waste is extremely promising in light of renewable resource utilisation (Ðimon and Czakó, 2014). Processing of biological waste by a corporate action of earthworms and microorganisms is involved in the production of the organic fertiliser vermicompost, which is rich in humic substances and mineral nutrients (Lazcano et al.,2008). This fertilizer improves soil fertility related characteristics (Ferreras et al., 2006) and has a multifaceted biological action on plants. Plant growth promotion (Ievinsh, 2011; Grantina-Ievina et al., 2013), and induction of resistance against pathogens (Zaller, 2006; Ersahin et al., 2009) and herbivores (Edwards et al., 2011, Cardoza and Buhler, 2012) are among the well-known effects of vermicompost application. In particular, plant growth-promoting activity of vermicomposts has been usually attributed to the high content of humic compounds (Muscolo et al., 1999)
In addition, because of the relatively high mineral content in vermicomposts, part of the growth-enhancing activity of vermicompost and vermicompost extracts might be due to the positive effect of additional mineral nutrients on plant growth (Karlsons et al., 2016).