In order to investigate the abiotic stress (drought) tolerance of oat (Avena sativa L.) with silicon and sulphur foliar fertilisation treatments, and monitor the effect of the treatments on the physiology, production, stress tolerance, plant, and grain quality of winter oat varieties, a field experiment was conducted in the growing season of 2020–2021. As a continuation of our article, published in another Special Issue of Plants, in this publication we evaluate the effect of silicon and sulphur treatments on the quality of winter oats. The whole grain sulphur content was significantly different between varieties. The foliar fertiliser treatments caused greater differences in both the carbon and nitrogen, and sulphur contents in the green plant samples, compared to the differences measured in the grain. Foliar treatments had a significant effect on the sulphur content of both plant samples and grains. Significant differences in the Al, Ba, Ca, Cu, Fe, K, Mn, Mo, Na, Ni, P, Pb, Sr, and Zn contents of oat grains were measured, both between treatments and between varieties. Winter oat varieties did not respond equally to the foliar fertiliser treatments in terms of either macronutrient or micronutrient content. When P, K, Ca, Mg, and S were summarised, the highest values were in the control plots. Significant differences in protein content were identified between winter oat varieties in response to the treatments, but the varieties did not respond in the same way to different foliar fertiliser treatments. Based on our results, we recommend the use of foliar fertilisation in oats in drought-prone areas.

Utilizing heat pumps has varied benefits, including decreasing the proportion of fossil fuels in the energy mix and reducing CO₂ emissions compared with other heating modes. However, this effect greatly depends on the type of external energy and the type of the applied heat pump system. In our study, two different types of heat pumps, three different modes of operation, three different types of auxiliary energy, and three different CO₂ emission values from electricity generation were selected to calculate the CO₂ emissions related to heating a theoretical house and calculate the CO₂ emissions reduction compared with gas firing. According to the calculations, a wide range of CO₂ emission reductions can be achieved, from scenarios where there is no reduction to scenarios where the reduction is 94.7% in monovalent mode. When operating in a bivalent mode, the values are less favorable, and several systems show no reduction, particularly when operating in an alternate mode at a bivalent temperature of 2 °C. However, the reduction in fossil CO₂ emissions can be kept at a high value (up to 56.7% with Hungary’s electricity mix) in a bivalent system by using biomass as a resource of auxiliary energy and geothermal heat pumps, which is very similar to the CO₂ emission reduction in monovalent systems (54.1%).

The aim of our report is to refer on the actual state of small biogas power plants in Hungary summarising the increase in their number and capacity and their effects on climatic change. The above is based on the CO₂ emission of the energetic utilization of biogas and the calculation of its ecological footprint that were compared to the environmental effects of natural gas energetic utilization. The aim of this paper does not include the complete life cycle analysis therefore the environmental benefits of the energetic utilization of biogas produced from various raw material are presented via only the direct CO₂ emission of the production process.

Powerful geothermal energy utilisation requires geoinformatic tools from potential surveying throughthe designing and setting of geothermal systems to certain operational tasks. However, practical dataprocessing strongly depends on the elaboration of basic data and information, the type of the geothermalenergy harvesting system and the character of the calculation demonstrated by case studies from EastHungary, in addition the usability of the resulted maps are also presented. Besides their usability forinvestors these maps could be refined in the location of the development before hydraulic/heat transportmodelling.

The role of geothermal energy is smaller in the global energy mix than what its potential would indicate, but it can be improved by incorporating geothermal energy potential assessments into spatial planning. For adequate decision support and sustainable utilisation, subregion-scale assessments should be applied due to the high variability in geothermal characteristics. Different GIS tools were used for the interpretation and integration of the different spatial data into one model showing areas with their geothermal characteristics on maps. Considering the present study site with a size of 83 km × 103 km located in NE Hungary, 39 2D reflection seismic sections and high-resolution geological data of 137 thermal wells were interpreted in OpendTect and then in ArcGIS to define spatial differences in geothermal potential. It was found that nine geothermal subregions (GSRs) can be distinguished in the present study site based on the applied GIS algorithms. Each GSR was characterised and land-use structure was studied based on Corine Land Cover 2018. The exploitation of water with at least 30 °C is possible in all GSRs, while the maximum achievable temperature and reservoir geometry vary; a subregion-scale delineation framework is required for regional planning.