No abstract

Technological and structural parameters of a threshing unit must ensure the highest possible quality of its operation under minimum input and cost. The aim of the study was to estimate the variation of speed of threshing cylinder with two different shapes of filler plates (FP-I and FP-II) under various corn ear feed rate into combine harvester. Threshing cylinder speed (frequency of rotation) nb (min-1) was measured simultaneously each 0.075 s using stationary tangential single-cylinder threshing unit located in laboratory-training ground intended for investigation into technological processes of agricultural machinery. Frequency of rotation of non-loaded threshing cylinder speed amounted for 450 min-1. Increase in corn ear feed rate from 6 kg s-1 to 12 kg s-1 caused frequency of rotation of threshing cylinder to decrease from nb=437.82±0.21 min-1 to nb=420.96±0.50 min-1 (using FP-I). Replacing covered spaces between rasp bars with FP-II had no effect on cylinder speed – it has decreased from 438.06±0.23 min-1 to 421.37±0.32 min-1. Results showed that in case of FP-I, the amplitude of speed Anb has increased from Anb=4.07±0.44 min-1 to Anb=8.60±0.88 min-1, whereas in case of FP-II – from Anb=2.67±0.25 min-1 to Anb=4.52±0.62 min-1 in response to increased feed rate from 4 kg s-1 to 12 kg s-1. This means that using the covers FP-II the threshing apparatus will work more evenly. The average threshing cylinder speed, irrespective of the closure of spaces between rasp bars, was found to decrease by approx. 20 min-1 in result of increase in corn ear feed rate from 4 kg s-1 to 12 kg s-1. When threshing corn ears, irrespective of the shape of filler plates, the acceptable feed rate amounted for 10 kg s-1, as it caused to exceed the permissible limit of 5 % allowed for decrease in cylinder speed (nb=427.5 min-1).

Corn ear feed rate variations in the threshing-separation unit of a combine harvester have a significant impact on the dynamic indicators of the threshing process. In this study, we conducted experiments using a stationary tangential threshing device and measured the forces acting on the rear part of the concave as well as the torque of the rotating cylinder during a threshing process. The ThreshLab software was developed for this purpose. We found that increasing the corn ear feed rate made the threshing process more even, due to decreasing the fluctuation of forces acting on the rear part of the concave and torque of the rotating cylinder. The corn ear threshing process may be more stable if the threshing cylinder is fitted with filler plates (FP-II). A comparison of the results obtained for variations in the forces acting on the rear part of the concave with those obtained for variations in the total torque of resistance and the speed of the threshing cylinder revealed a linear correlation between these parameters at varied feed rates. DOI: http://dx.doi.org/10.5755/j01.mech.24.4.20721

Agricultural management, environmentally friendly technologies, chemical, organic and bio-based substances used, as well as meteorological factors, have a significant impact on the fluctuations of soil organic carbon (SOC). The aim of this research was to analyze the effect of different biopreparations on the changes of SOC content and the winter wheat and winter oilseed rape yields by assessing the energy consumption efficiency and the environmental impacts. The experimental research was conducted from 2017 to 2019 in three different treatments, in two of which were used either a molasses and magnesium sulphate based-biopreparation (T1) or a bacteria-based biopreparation (T2), while treatment T3 was applied as a control where no biopreparations were used. The dynamics of SOC content were analyzed at two depths: 0–10 and 10–20 cm. For the analysis of energy efficiency indicators and environmental impacts, the greenhouse gas (GHG) and energy consumption conversion equivalents were used. A summary of the results showed that both types of biopreparations had a positive effect on the changes of SOC content, which was especially evident in the deeper layers at 10–20 cm depth, where, irrespective of the crop type, a more significant increase of the SOC content was observed every year of the experiment compared to the control treatment. Biopreparations had a significant effect in increasing the winter wheat and winter oilseed rape yield. The best energy efficiency ratio was observed in winter wheat (4.84) and winter oilseed rape (5.11) in treatment T1. The results of the environmental impact assessment showed that the lowest GHG emissions were recorded in the winter wheat production in treatment T1 at 108.7–149.1 kg CO2eq Mg−1, while the highest were observed in oilseed rape production in the control treatment T3 at 343.4 kg CO2eq Mg−1.

Abstract. Soil organic carbon is one of the key qualitative soil parameters. I`t affects soil vitality, its humus content, microorganism activity, soil CO 2 emissions, as well as basic fertilizer needs and plants' ability to source nutrients. According to Christopher and Lal (2007), the carbon (C) cycle is closely related to the nitrogen (N) cycle in plants and soil organic matter. The application of precision farming can aid in determining the exact content of organic carbon in soil and the appropriate carbon -nitrogen ratio for plant growth, digestion and absorption of waste. The aim of this work is to determine the impact of biological preparation on the soil organic carbon content, fertilizer needs, harvest and environment. Experimental research was conducted in Pasvalys district, coordinates 55.920437, 24.212736 (WGS); 3 cases were researched: SC1 -biological preparation "Product 1", SC2 -biological preparation "Product 2"; SC3 -no biological preparation (control). Veris P4000 VIS-NIR equipment was used for this research in order to estimate the soil organic carbon content, electrical conductivity, soil hardness and to do spectral analysis in the 380-2200 nm wavelength range in 0-100 cm depth. Research indicates that in the SC1 case, the soil organic carbon content grew from 1.8 % to 2 %, compared to SC3, where the soil organic carbon content change was negative and fell from 2.2 % to 2,09 %. The maximum yield was reached in the SC2 case and resulted in 5.38 t·ha -1 , compared to 5.26 t·ha -1 (SC1) and 4.37 t·ha -1 (SC3).