Lucjan Pawłowski

In the face of increasingly frequent natural disasters resulting from climate change and disruptions in the supply chains of energy resources, the demand for energy carriers based on locally sourced renewable resources is growing. Biomethane, derived from biomass and having multiple uses in the energy sector, fully meets these conditions. Analyses of the development and spatial distribution of biomethane production plants, the prevalence of methods of its production, and directions of applications, made on the basis of the data gained from official databases and research papers, are the main subjects of the paper. Additionally, the advantages and disadvantages of biomethane production, taking into account the results of the life cycle assessments, and the prospects for development of the biomethane market, facing regulatory and policy challenges, are considered. The results of the review indicate that biomethane production is currently concentrated in Europe and North America, which together generate over 80% of the globally produced biomethane. An exponential growth of the number of biomethane plants and their production capacities has been observed over the last decade. Assuming that the global strategies currently adopted and the resulting regional and national regulations on environmental and socio-economic policies are maintained, the further intensive development of the biomethane market will be expected in the near future.

Agriculture is the second-highest, after energy use, source of greenhouse gas emissions, which are released from soils and animal digestion processes and as a result of energy consumption at various stages of agricultural production. However, changes in the management of agricultural systems may mitigate the negative impact of this sector on the atmosphere and climate. This paper presents a literature review on energy consumption in agriculture and the potential of agricultural crop production to assist in mitigation of global warming by increasing absorption of CO₂ from the atmosphere. The issue was considered in the context of managing the cultivation of main, catch and cover crops. The potential of carbon sequestration in the above- and below-ground biomass of selected crops was analyzed. It was stated that, depending on the species, main crops can sequester up to 113 CO₂ ha⁻¹ yr⁻¹ in whole biomass, while catch or cover crops can sequester up to 14.80 CO₂ ha⁻¹ yr⁻¹ and 0.17 CO₂ ha⁻¹ yr⁻¹ in the above- and below-ground biomass, respectively. The benefits of the spread of catch or cover crops, such as improvement of soil quality (leading to an increase in primary crop yield by even as much as 65%) and a phytosanitary effect, as well as the barriers that limit the use of catch crops, including the problems with matching crop species to climate and soil conditions and the risk of reducing farmers’ income, were considered. The results of the review show that catch crops can assimilate an additional amount of 4 to 6 tonnes CO₂ ha⁻¹ yr⁻¹, and thus, spreading of catch crops is an effective way to reduce the climate impact of agriculture.

Industry 4.0 and related new technologies have a negative impact on air pollution, waste generation and the intensive use of raw materials, information and energy [1, 2]. Consequently, efforts have been made to integrate sustainability into the operations of companies. In the countries of the European Union, there is a need to look for solutions dedicated to Industry 4.0, which will reduce the negative impact of new technologies on the environment. Manufacturing technologies (e.g. 3D printing) are also gaining importance. New production technologies must minimise waste and eliminate the use of hazardous materials [3]. Waste recovery and treatment technologies also need to be developed and implemented. These must be energyefficient technologies. Pro-environmental measures should be analysed and refined throughout the product development process, as they can only produce the best results. Within organic production, companies can already plan and realise resource consumption through digital simulations in the aspect of the Circular Economy [4, 5]. Another aspect we want to consider is new production technologies in Agriculture 4.0, which is starting to actively use Industry 4.0 solutions [6]. The aim of the Special Section Sustainability in production in the aspect of Industry 4.0 is to present the latest developments and applications in the following topics: • New and innovative techniques in design and manufacturing in the aspect of sustainability. • Impact of new and innovative techniques on the environment. • Computer tools supporting environmental analysis. • Computerisation of production and environment in the aspect of Industry 4.0. • Eco-design. • Ecological awareness of companies. • "Green practices" in companies.

Reviewing the current state of knowledge on sustainable production, this paper opens the Special Section entitled “Sustainability in production in the context of Industry 4.0”. The fourth industrial revolution (Industry 4.0), which embodies a vision for the future system of manufacturing (production), focuses on how to use contemporary methods (i.e. computerization, robotization, automation, new business models, etc.) to integrate all manufacturing industry systems to achieve sustainability. The idea was introduced in 2011 by the German government to promote automation in manufacturing. This paper shows the state of the art in the application of modern methods in sustainable manufacturing in the context of Industry 4.0. The authors review the past and current state of knowledge in this regard and describe the known limitations, directions for further research, and industrial applications of the most promising ideas and technologies.

With the acceleration of the Belt and Road Initiative, Poland–China agricultural trade has increasingly strengthened, but there is little exchange or cooperation in agricultural machinery. China’s agricultural UAV industry has flourished over the past 7 years. In China, by using typical food crops and economic crops to control diseases and pests, agricultural drones can reduce the use of fertilizer, pesticides, and water, improve operational efficiency, open up new markets through the ‘sale + services’ mode, and reduce production costs and labor shortages. The spraying of agricultural UAVs and related pest-disease-defense services applied in China are also suitable for Poland’s decentralized, small-scale production modes. By learning from China’s development progress of precision-agriculture aviation, Poland can develop 5th-generation (5G) unmanned intelligent organic farms from traditional organic agriculture, use agricultural UAVs in the spraying of Plant Protection Products (PPPs), and carry out special protection or loss management on typical fruits. Furthermore, by building its own spraying system, aviation industry, and service team, Poland can realize resource optimization, technological empowerment, application expansion, and industrial innovation. Therefore, this paper focuses on the development experience of Chinese agricultural UAVs and discusses its enlightenment to the precision-agriculture aviation application of Poland.

The role of catch crops in modern agriculture has increased in recent years. In addition to a production of animal feed, they have a positive impact on quality of soil. This study determined the suitability of selected stubble catch crops (white mustard, lacy phacelia, and a mixture of faba bean + spring vetch) to improve production, economic and energy effects of spring wheat grown in 3-year monoculture relative to the control treatment (without catch crops). Two tillage systems were used: conventional tillage and no-tillage (conservation tillage). A field study was conducted over the period 2014-2016 at the Czeslawice Experimental Farm, Lubelskie Voivodeship, Poland. The study proved the high suitability of catch crops to increase the spring wheat yields (under both tillage systems). Regardless of the catch crops, the productivity of wheat was higher under conventional tillage. The catch crops (in particular white mustard) and the conservation tillage system contributed to an improved energy efficiency index of production. The white mustard catch crop also had the most beneficial effect on the economic profitability of spring wheat production. This was due to the low cost of cultivation of this catch crop and its beneficial impact on obtaining high yields of spring wheat.

Biomass, a basic product of agriculture, is one of the main sinks of carbon in global cycle. Additionally, it can be used as a renewable source of energy, leading to depletion in CO₂ emissions. The paper presents the results of estimations on the current and potential share of catch crop cultivation in climate change mitigation, in Poland, where the agricultural sector plays a significant economic role. The estimation of CO₂ assimilation in biomass was performed on the basis of our own data on yields of commonly used catch crops, obtained in randomly selected 80 farms in Poland, and the content of carbon in the biomass. Calculation of energy potential of the biomass was conducted, assuming its conversion into biogas, on the basis of our own data on catch crop yields and the literature data on their biomethane potentials. The results have shown that catch crops in Poland, which are cultivated to an area of 1.177 mln ha sequestrate 6.85 mln t CO₂ yr⁻¹. However, considering the total area of fields used for spring crop cultivation, it is possible to increase the sequestration to 18.25 mln t CO₂ yr⁻¹, which constitutes about 6% of the annual emission of CO₂ in Poland. Biomethane yields per hectare of particular crops ranged from 965 to 1762 m³ CH₄ ha⁻¹, and were significantly lower compared to maize, which is commonly in use in biogas plants. However, due to high biomethane potential and favorable chemical composition, catch crops can be a valuable co-substrate for the feedstocks with a high C:N ratio. The potential recovery of energy produced from aboveground biomass of catch crops harvested in Poland during the year is 6327 GWh of electricity and 7230 GWh of thermal energy. Thus, it is advisable to promote catch crops on a wide scale due to substantial environmental benefits of their cultivation.

The global fluxes of carbon in the ecosystem of Earth, with particular attention drawn to the cycle of CO₂were characterised. The sequestration of carbon dioxide in the biomass of plants, especially the ones which can be cultivated as catch crops is described. It was shown that the cultivation of catch crops may play an important role in the mitigation of CO₂emissions.