Biomass formation and yield performance in diverse multicrops and their potential for biofuel use

Herbaceous plant biomass is an important resource for energy production and an effective strategy to ensure energy supply independence. Growing agricultural plant mixtures (multicrops) contributes to increasing biomass yields, enhancing farm biodiversity, improving soil health, and promoting environmental sustainability.. However, most crop mixtures have not been studied at all. For this reason, research was conducted from 2020 to 2022 at Vytautas Magnus University, Agriculture Academy. The aim of the study was to evaluate the development and productivity of plant mixtures, as well as the related energy and environmental aspects of the applied agrotechnologies, under short-growing-season conditions. Ternary crops tended to be 14% taller, with 24% higher leaf assimilation area, 19% higher chlorophyll index, and 4–8 times higher first-year dried biomass yields than individual single-species crops. The productivity of the ternary crop reached its highest Comprehensive Evaluation Value (4.54), which was mainly influenced by the chlorophyll index of the leaves. Ternary cultivation was the most fuel-consumptive technology, with 18–32% higher fuel consumption (103.3 L ha ^− 1 ), due to its higher energy input; however, it generated the most significant net energy (367,668.1 MJ ha ^− 1 ) because of its most abundant yield of dried biomass. Ternary crop biomass pellets had the highest density (1,238 kg m ^-3 ), lower ash content (6%), and the highest ash shrinkage starting temperature (1042° C). It is advisable to cultivate high-capacity yielding ternary crops for one year, which have medium GHG emission and LCA impacts of the pellets produced, but the highest net energy output.