The purpose of this work is to determine the impact of selected silage maize cultivation technologies, including energy inputs in the production chain (cultivation, harvesting, heap placing), on energy efficiency. The analysis of energy inputs, energy efficiency for the silage maize production technology were estimated. The research was performed for 13 farms producing silage maize. The data from the farms covered all the activities and the agrotechnical measures performed. The calculations of energy inputs made for the silage maize production for selected technologies were performed using the method developed by the Institute of Construction, Mechanization and Electrification for Agriculture (IBMER), once the method was verified and adapted to the needs and conditions of own research. Based on the accumulated energy production and the energy accumulated in the yield, energy efficiency index values for 13 silage maize cultivation technologies were calculated. The greatest impact on the results of energy efficiency calculations was shared by fertilizer and fuel inputs. In conclusion, it can be stated that, in terms of energy efficiency, maize cultivation is justified and it can generate energy benefits.

A digital elevation model (DEM) is an essential element of input data in the model research of watersheds. Recently, progress in measurement techniques has led to the availability of such data with high spatial resolution. Therefore, simplification of DEMs to shorten the time of their processing is a significant, but insufficiently investigated issue. This study, gradually and with various methods, carried out a great simplification of a detailed LiDAR-derived DEM. Then, the impact of that treatment on the precision of the selected elements for modeling a watershed was assessed. The simplification comprised a reduction in resolution, with the use of statistical resampling methods, namely giving an average, modal, median, minimum, maximum, or the closest value to the pixels. This process was carried out in a wide range of pixel sizes, increasing by 50% each time (from 1 m to 1.5, 2.3, 3.4, 5.1, 7.6, 11, 17, 26, 38, 58, and 86 m, respectively). The precision of the obtained DEMs and the precision of the delineation of boundaries of the watershed and watercourses were assessed. With the systematic reduction in the resolution of a DEM, its precision systematically decreased. The changes in the precision of determining the watercourses and boundaries of a watershed were irregular, ranging from being very small, to mild, to significant. A method of giving the minimum value, that was simple with regard to computing, was singled out. In the determination of both the watercourses and the boundaries of a watershed, this method produced one of the best results for the higher resolution and for the lower resolution—considerably better than the other methods tested. The research was conducted on a flat agricultural catchment, and it can be assumed that the obtained conclusions can be considered for similar cases. For catchments with different characteristics, further research is advisable.

The paper determines the effect of selected cultivation technologies, including production chain energy inputs (growing, harvest, heap forming) on greenhouse gas emissions (GHGs) to the atmosphere. The data for the study was collected from 13 actually operating family farms ranging in size from 2 to 13 ha, located in the Podlaskie voivodship (Poland). GHG and ammonia (NH₃) emissions from natural and mineral fertilisation as well as GHGs from energy carriers in a form of fuels (ON) were estimated. The average GHG emissions from the sources analysed were 1848.030 kg·CO₂eq·ha⁻¹ and 29.492 kg·CO₂eq·t⁻¹ of the green forage yield. The average NH₃ emissions per hectare were 15,261.808 kg NH₃ and 248.871 kg NH₃·t⁻¹ of yield. The strongest impact on the environment, due to the GHG emissions to the atmosphere, thus contributing to the greenhouse effect, is due nitrogen fertilisation, both mineral and natural. On average, in the technologies under study, 61% of the total GHG emissions came from fertilisation. The GHG emissions were correlated with the energy efficiency, calculated at the previous research stage, of the production technologies applied. There is a negative correlation (r = −0.80) between the features studied, which means that the higher the energy efficiency of the silage maize plantations, the lower the air pollution emissions in a form of the GHGs from the sources under study. It is so important to prevent environmental degradation to continue, conduct in-depth, interdisciplinary research on reducing the energy consumption of crop production technologies and striving to increase energy efficiency.

Nettle is most often studied as a spinning plant, as a source of biochemicals and environmentally safe fungicides. Major studies are mostly conducted on natural samples and plant populations. Prospects for the use of plant biological resources of stinging nettle (Urtica dioica L.) from the Cretaceous south of the Central Russian Upland to create cultivars for a wide range of applications are considered. The aim of the study is to investigate the productivity of fresh weight and its biochemical composition in the variety of stinging nettle Avicenna, created on the basis of the initial material selected in the Belgorod region of Russia and patented in 2019, and new promising cultivars UD 32/06 and UD 12/16. The experiments were carried out by the split plot method with full randomization in four replicates. The cultivars UD 32/06 and UD 12/16 reliably surpass the Avicenna cultivar in the collection of fresh mass weight by 16.6–22.7% and 23.1 to 27.8%, dry weight by 11.4–28.7% and 1.9–32.7%, and seeds by 19.7–32.0% and 23.2–40.0% accordingly. Analysis of variance showed a significant effect of the factor “Cultivar” on the productive traits “Fresh weight yield” (strength influence 87.2%), “Dry weight yield” (strength influence 43.9%), and “Seed yield” (h²x = 61.6%). The content of crude protein in dry weight of the Avicenna and new varieties is 21.1–24.2%, crude fat: 2.5–4.2%, fiber: 12.0–14.8%. High content of ascorbic acid, calcium, phosphorus, iron, and zinc were observed in all material tested. It is concluded that the biological resources of the wild-growing forms of Urtica dioica L. from the European south of Russia are a valuable source material for obtaining varieties, and varieties with high productivity of the aboveground mass and stable seed productivity. The obtained research results prove the usefulness of nettle cultivation.

This paper presents the results of research on the energetic use of self-combusted hemp pellets and co-firing with pine pellets. The tests were carried out with the use of a boiler equipped with a Lester Projekt Company gasifying burner and an automatic fuel feeding system. The boiler is equipped with an additional heat exchanger that enables the simulation of any heat load. The experimental stand so built guaranteed to obtain results adequate to the real operating conditions. The research material consisted of pellets made of waste biomass of the Futura 75 sowing hemp and pine sawdust pellets. The experiment was carried out in five proportions by mass of mixtures of both fuels (C-hemp, P-pine): 0:100 (P100), 25:75 (C25/P75), 50:50 (C50/P50), 75:25 (C75/P25), 100:0 (C100). For each variant, the following were determined: effective boiler power, boiler energy balance, boiler energy efficiency, the volumetric composition of flue gas (carbon monoxide, carbon dioxide, hydrogen, sulfur dioxide, nitrous oxide), excess air coefficient and the dust content of particle matter—PM10, PM2.5. The heating value was also determined for hemp pellets and pine sawdust pellets, accordingly 17.34 and 19.87 MJ·kg⁻¹. The obtained test results were related both to the volume of exhaust gases leaving the boiler and to one kilowatt hour of heat produced. The obtained test results showed that the boiler fed with pine pellets achieved the highest thermal power (P100)—14.17 kW, while the smallest—hemp pellets (C100)—4.92 kW. The CO₂ emissivity increased with the addition of pine pellets, from 26.13 g (C100) to 112.36 g (P100) relating to 1 m³ and from 430.04 g (C100) to 616.46 g (C25/P75) relating to 1 kWh of heat. In terms of dust emissions, it was found that the combustion of hemp pellets and mixtures thereof is a little worse than that of pine pellets.

The study estimates the amount of emissions resulting from linear sources. There were calculations for a model rural municipality, composed of national, provincial, country, and municipal roads that run through the area. In this study, the following categories of vehicles were assumed to travel along this route: motorcycles, passenger cars, light trucks (vans), heavy trucks without trailers, trucks with trailers, and buses. The analysis used data on the average volume of traffic (SDR) on selected roads on the territory of the sample municipality, based on the frequency of participation in traffic by each mode of transportation on selected road sections. To estimate the emission rates of each pollutant, for each vehicle category separately, the calculations were made based on the emission factor rates for each type of fuel. According to the adopted methodology and based on the adopted assumptions scenarios, pollutants’ emissions were estimated. The implementation of the scenarios offered for reducing CO₂ emissions has been proposed, and it is estimated that, depending on the variant adopted, the reductions will be between 13 and 21% in variant I, between 3 and 8% in variant II, and between 18 and 34% in combining these variants. The variant with a reduction in private car transportation in favor of bicycle transportation in combination with public transportation showed the most favorable effects on the environment.