When processing barley for the brewing and food industries, one of the process steps is the separation of barley grains. After separation, waste fractions are created that contain damaged grains, dust, stones, grass, clay residues, etc. The waste fractions therefore contain recyclable components. It is important to find a suitable way to use these waste fractions. This research is focused on the possibilities of applying torrefied waste fractions as soil enrichment to support plant growth. The first waste fraction contained lower-quality barley grains that are used as feed for livestock. The second waste fraction contained grass seeds and chaff and can be used as feed for forest animals. The third waste fraction, which contained aspiration dust, is currently being incinerated and disposed at biogas plants. Experiments were conducted with different ratios of torrefied fractions added to the soil and the values of total nitrogen were analyzed as an indicator of the benefit to the soil. The results showed that torrefied waste fractions exhibit positive properties for plant growth. The best results were achieved with a mixture containing 10 and 50 % of soil enriched with torrefied second and third waste fractions. Experiments confirmed a positive effect on plant growth, which suggests the possibility of applying this procedure in practice. Compared to current research, this method can contribute to the sustainable management of biowaste and its effective use for improving soil conditions with a high potential for sustainable agriculture.

The use of biochar in agriculture is associated with the concepts of carbon sink and carbon negative, which will constitute additional income for farms in the near future and may provide them with a key role in the fight against global warming. The existing model in the Scandinavian countries is one of the first to combine biochar with carbon dioxide biosequestration. Fertilizers with excessive nutrient content, salinity issues, impurities, or irregular pH levels can induce phytotoxicity, damaging plant health and growth. Torrefied woody biomass can work as a bulking agent, carbon carrier, or as an amendment for composting materials containing high amounts of water and/or nitrogen contents. Superheated steam torrefaction as a valorization process increases the amount of pores in which minerals can be stored and the plant will grow faster and bigger by using these pores agglomerated minerals. The torrefaction process was conducted using the DynTHERM TG Rubotherm high-temperature and high-pressure thermogravimetric analysis apparatus under conditions of superheated steam flow. Various residence times (10, 20, and 40 min) and torrefaction temperatures (250, 275, and 300 degrees C) were explored to assess their efficacy in reducing the phytotoxicity of torrefied spruce. To confirm this assumption, a toxicity test with Lemna minor L. was carried out according to Radi & cacute; et al. (2011) and extended to the determination of chlorophyll index and chlorophyll fluorescence to assess the physiological status of the plants after treatment with different doses of spruce wood biocarbon. Research indicates that biochar positively impacts soil quality and plants. Thanks to its unique properties, biochar provides nutrients, enhancing fertilization efficiency [1]. Biochar, after concentrating and adsorbing the nutrients from the wastewater, can be used as a soil amendment or fertilizer. Biochar blended with organic residues full of nutrients is more effective in improving soil properties and crop yields than the exclusive application of pure biochar or other fertilizers. Traditional chemical fertilizers have drawbacks, such as rapid nutrient leaching, severe environmental pollution, and high costs. Therefore, biochar is gaining increasing recognition worldwide.