Soybean (Glycine max L.) is one of the most important crops grown globally. Biochar has been proposed as an alternative to aid sustainable soybean production. However, comprehensive studies that include both the economic aspects of soybean production and biochar are scarce. Poland, with an economy largely based on agriculture, is an interesting case to investigate the cost-effectiveness of using biochar in soybean production. We show that the use of biochar at rates of 40, 60 and 80 t/ha is unprofitable compared with a traditional soil amendment, such as NPK fertilization. The breakeven price for biochar to be economically viable should be USD 39.22, USD 38.29 and USD 23.53 for 40, 60 and 80 Mg/ha biochar, respectively, while the cost of biochar used for this experiment was USD 85.33. The payback period for doses of 40 and 60 Mg/ha was estimated to be three years. With a carbon sequestration subsidy of USD 30 per ton of CO₂, the use of biochar may be profitable in the first year of soybean production. This is the first comprehensive economic analysis of the use of biochar in soybean production in Poland and one of the few published worldwide.

Comprehensive environmental impact assessments of buildings and construction as a whole consider the preparation of construction and finishing materials, their transportation, the process of erecting buildings, long-term operations—including the consumption of electricity, water, and fuels—and the management of the waste generated during the demolition of facilities. In terms of the above-mentioned elements, the most negative environmental impact on a building’s life cycle is in its exploitation stage. In order to reduce this impact, modern sustainable construction uses renewable energy sources. In the area of the Polish building market, analyses of CO₂ emissions, the application of LCAs for building materials, and assessments of the social impacts of modern buildings are still very limited. The aim of this study is to evaluate the environmental life cycles and social costs of the CO₂ emissions of single-family residential buildings, in which four different systems providing energy (heat and electricity) from renewable and nonrenewable sources are used. In this research, it was found that the annual CO₂ emissions per square meter of building surface area in the analyzed objects were in the range of 30 to 176 kg CO₂. The greatest contributor to the environmental effects was energy consumption (58% to 90%). The CO₂ analysis conducted showed that facilities that use a heat pump are characterized by an environmental effect that is six times lower than that of facilities that are powered by coal combustion and electricity from the network. Similarly, the social costs associated with CO₂ emissions were significantly lower in the case of the use of renewable energy sources.

Climate change has a decisive impact on the physical parameters of soil. To counteract this phenomenon, the ongoing search for more effective agri-technical solutions aims at the improvement of the physical properties of soil over a short time. The study aimed to assess the effect of biochar produced from sunflower husks on soil respiration (SR), soil water flux (SWF), and soil temperature (ST), depending on its dose and different soil cover (with and without vegetation). Moreover, the seed yield was assessed depending on the biochar fertilization. Field experiments were conducted on Calcaric/Dolomitic Leptosols (Ochric soil). SR, ST, and SWT were evaluated seven times in three-week intervals during two seasons, over 2018 and 2019. It was found that the time of biochar application had a significant effect on the evaluated parameters. In the second year, the authors observed significantly (p < 0.005) higher soil respiration (4.38 µmol s⁻¹ m⁻²), soil temperature (21.2 °C), and the level of water net transfer in the soil (0.38 m mol s⁻¹ m⁻²), compared to the first year. The most effective biochar dose regarding SR and soybean yield was 60 t ha⁻¹. These are promising results, but a more comprehensive cost-benefit analysis is needed to recommend large-scale biochar use at this dose.

Organic matter is an indispensable element of soil. Its quantity and quality affect its properties, e.g., structure, buffering, sorption capacity, air–water relations, and thermal properties. The purpose of the research was to assess greenhouse gas (GHG) emissions in soybean cultivation, fertilized with biochar from various crops. Two experimental factors were included: the dose of biochar and the type of biochar used as per raw material used in its production. The adopted functional unit was 1 ton of soybeans. To reach the adopted goal, a strict field experiment was carried out. The total amount of GHG emitted by the cultivation was calculated according to the ISO 14040 and ISO 14044 standards. The system boundaries included: GHG emissions from fertilizers and seeds used, GHG emissions related to biochar production, emissions related to fossil fuel combustion, and emissions related to the decomposition of crop residues and soil organic matter and the decomposition of biochar. The results of the research indicate a significant potential of biochar to reduce GHG emissions in agricultural production. From the environmental and production perspective, the addition of biochar at 60 Mg ha⁻¹ is the most advantageous. A further increase in the addition of biochar was related to a decrease in plant yield and an increase in GHG emissions per functional unit of the product. The use of biochar in soybean cultivation resulted in a 25% reduction in GHG emissions compared to the object without the biochar addition. The amount of GHG emissions for soybeans ranged from 846.9 to 1260.1 kg of CO₂/Mg. The use of biochar from forest biomass resulted in a higher yield, 12% on average, compared to sunflower husk biochar. The introduction of biochar to soils can be an effective improvement in the economic and environmental efficiency of plant production, as it increases the use of nutrients by the plant and intensifies carbon sequestration in soils.

This paper presents results of work on the reduction of toxic metal content while decreasing its oxygen activity. During the study the effects of different doses of ozone in the air used for aeration of the stabilized compost in the first post-thermophilic phase were analyzed. The results showed...