Growing as much crop biomass as possible in the shortest possible time is the target for most bio-energy producers. However, according to the requirements of the Green Deal, the consumption of fertilizers and crop protection products will have to be significantly reduced between 2023 and 2027. In order to meet all the necessary conditions for the production of biomass, a stationary field experiment was carried out at the Experimental Station of Vytautas Magnus University, Lithuania, in 2020–2021. Multi-cultivations of maize, hemp and faba bean were investigated. The aim of this study was to ascertain the impact of multi-cropping intensity on soil structural composition, stability, penetration resistance and gas concentration–respiration. As expected, multi-cropping stabilized the gas concentration and emission from the soil and decreased the proportion of micro-structures in the top soil layers. However, the stability of the soil decreased in all the experimental plots. Gas concentration and respiration mainly depended on soil structural composition, temperature and moisture content. The results of the experiment suggest performing investigations at a long-term scale because the intensive variation of meteorological conditions had a higher impact on the soil properties than the multi-cropping systems.

As solid biofuels gain increasing importance, the issue of rational management of the ash obtained from biofuel combustion is becoming increasingly relevant. This relevance will only increase in the future, since it is predicted that the main biofuel raw material will not be wood, but agricultural biomass with a high ash content. Biomass ash contains valuable nutrients, such as potassium and phosphorus, and therefore, it could be used for fertilization in agriculture. The concentration of nutrients in the ash can be made more balanced by granulating it with organic waste. This work presents the results of the environmental impact of using multi-crop biomass ash for fertilization of spring barley using the life cycle assessment method. Five scenarios were analyzed: (1) mineral fertilizer (MF), (2) non-granulated ash (NA), (3) ash and cattle manure pellets (ACM), (4) ash and sewage sludge pellets (ASS), and (5) ash and sapropel pellets (ASP). The results of the study show that all scenarios using ash for fertilization have a lower environmental impact compared with the scenario using only mineral fertilizers (MFs). The lowest carbon footprint (583.94 CO_2eq.) was determined for the ASP scenario. Normalization of the results showed that the ASS and ASP scenarios are the best from an environmental point of view, with the lowest environmental impact (24.90 and 24.60 Pt, respectively).