There is no specialized equipment designed to spread granular cylindrical organic fertilizer in the soil. There are also no rational recommendations available on how to spread this type of fertilizer. Mineral fertilizer spreaders are most often used for spreading granulated organic fertilizer. However, these fertilizers are significantly different from mineral fertilizers. Due to these differences, organic granular fertilizers often are spread unevenly, and the fertilizer does not reach the required working width. Furthermore, the rate of spreading is not accurate, and the fertilizer is often crushed too much. The objective of this research is to develop a simulation model for granular organic fertilizer applications with a centrifugal spreader in EDEM (extended distinct element method) software. It is possible to develop a numerical model that corresponds to a real spreader, and to determine the key physical–mechanical parameters for the application of granular organic fertilizer. This model can also be used for evaluating the transverse uniformity of the fertilizer in the field (along the trajectory normal to the machine). The results of this research show that the distance traveled by the fertilizer granules partially depends on the particle size, initial speed, type of fertilizer and the parameters of the spinning discs of the spreader.

Granular organic fertilizers have been increasingly used in agriculture due to the longer delivery of nutrients to plants and the milder impact on the environment. The aim of this study was to determine the energy, environmental and economic efficiency of granular and non-granular organic fertilizers. Four technological scenarios of organic fertilizer use were used for comparative assessment: (1) manure fertilization (16.0 t ha⁻¹), (2) manure fertilization (30.0 t ha⁻¹), (3) manure pellet fertilization (2.0 t ha⁻¹), and (4) fertilization with meat and bone meal pellets (0.7 t ha⁻¹). Experimental studies using the mass flow method of laser spectroscopy were performed to evaluate the comparative environmental impact of granular and non-granular organic fertilizers. Economic assessment was performed for mechanized technological operations of loading, transportation and distribution of organic fertilizers, estimating the price of aggregates used and fuel consumed, the costs of individual technological operations and other indirect costs. The results showed that for mechanized technological operations, when fertilizing with granular organic manure and meat and bone meal fertilizer, energy consumption is 3.2 to 4.0 times lower compared to fertilization with manure. The average ammonia (NH₃) emissions from granular organic fertilizers were found to be six times lower than from non-granular organic fertilizers. The lowest costs for mechanized works were incurred when using meat and bone meal pellets, the highest economic benefits of organic fertilizers by elements was when using manure 30 t ha⁻¹, and the highest costs for organic fertilizers were incurred when using manure pellets.

A need for the disposal of poultry manure and the reduction of its impact on the environment encourages the search for cleaner and more efficient ways to utilize and recycle production waste. It is known that granulated ash and manure are the most effective alternatives for ash and manure recycling, as compared to the unprocessed product. This paper presents an investigation of ash and poultry manure recycling for granulated fertilizers. Accepted standard experimental methods were used. The physical and mechanical characteristics of the granules, elemental composition ratio, and the process of compression of the raw material mill were determined experimentally. This research shows that, when a higher ash concentration was determined, the initial bulk density was larger and the density and pressure in the granulation process increases faster. The content of ash in the raw material increased granule strength; however, when increasing the ash mass in the raw material from 25% to 50%, energy consumption increased from 6.59 kJ·kg⁻¹ to 17.72 kJ·kg⁻¹. The process of compression of the raw material mill was obtained in two stages. In the first stage of compression, the mass density varied from 3–11 kg·m⁻³ and the pressure varied from 1.25–8.27 MPa. In the second pressure stage, the mass deformation was elastic and the pressure process was described by indicator functions.

In agricultural activities, there is an increasing need for organic fertilizers to use nature-friendly materials used to fertilize the soil. Farmers have been using granular organic fertilizers made from composted or dried manure of cattle, poultry, pigs, ash, bone meal, and other materials for some time, but the quantities of these organic fertilizers are not large. Biochar is also being intensively studied as a material to improve soil quality and plant growth and reduce greenhouse gas emissions from soil. The suitability of cattle manure compost, poultry manure, biochar, and their combinations for granular fertilizers was analyzed in this work. The preparation of biochar for granulation may have differences compared to other organic materials due to the moisture content, fractional composition, bulk density, and other parameters of the granulated material, so this work examines the physical–mechanical and chemical properties of cattle and poultry manure and biochar raw material and the final granulated product. Research has found that the fractional composition of raw materials under investigation manure and biochar was up to 2 mm. The moisture content of the studied raw material varied from 8.97% in the case of poultry manure to 25.11% in the case of cattle manure compost. The lowest moisture content was obtained due to additional drying. The addition of biochar reduces the granule density in investigated cases. Poultry manure granules were the most mechanically stable, with a semi-static stability of 382.6 ± 78.08 N. After the addition of biochar, weaker binding properties were determined in the experimental granules. Analysis of the composition of elements shows that these granules can be used for fertilization or soil improvement. High concentrations of nitrogen (N), phosphorus (P), and potassium (K) were detected in the granules. The obtained results showed that it is appropriate to enrich the manure granules with biochar.

Testing the reliability of the threshing unit is difficult and thus often neglected before the harvesting season, which can result in breakdown maintenance during peak harvesting time in difficult-to-access areas for sensor mounting. In this paper, the vibration analysis of the threshing condition of the combine harvester was performed by introducing the bracket for inaccessible locations. The Adash A4900 Vibrio M analyzer (Adash spol. s.r.o., Ostrava, Czech Republic) was used for a vibration signal measurement and the DDS Adash software was used for signal processing. The demodulated fast Fourier transform (FFT) root mean square (RMS) (500 Hz–16 kHz) method was used to evaluate the bearing condition and DDS Adash Fault Source Identification Tool (FASIT) technology was used to evaluate other mechanical conditions such as the looseness, misalignment, and unbalance of the threshing unit of the Massey Ferguson series of combine harvesters. Modal and random vibration analyses were performed on the bracket and components and compared to prevent the resonance phenomenon using the Ansys Software (Ansys, Inc., Canonsburg, PA, USA). The constrained modal analysis of the threshing drum was performed to observe the deformation. Decent results were obtained from the method used. The method was again validated by the tangential threshing test bench and successfully determined the bearing fault condition. The method used is an uncomplicated and effective way of performing the bearing analysis of the tangential unit of the combine harvester.

Due to the continuous creation of organic granular fertilizers of the new composition, there is a lack of knowledge about their properties and the influence of the norm on spreading efficiency. To increase the efficiency of the use of granular organic fertilizers, their spreading aims are to properly choose the most rational spreading parameters and fertilizer norms, considering the characteristics of the fertilizer. To determine this quickly and with lower costs, various theoretical models and computer programs are used to study the dynamics of fertilizer spreading. The purpose of this work was to perform theoretical and experimental comparative studies of the influence of the characteristics and dosage norms of granular fertilizers of poultry manure on the spreading efficiency. During the research, the physical properties of granular poultry manure fertilizers were determined, which have an impact on the quality of spreading. Experimental studies of fertilizer spreading were carried out using two centrifugal spreaders with the same parameters (Amazone ZA-M-1001 (spreading dosage norm, 200 kg ha⁻¹ and 400 kg ha⁻¹; driving speed, 10 km h⁻¹) and ZA-M-1201 (spreading dosage norm, 600 kg ha⁻¹, 800 kg ha⁻¹, and 1000 kg ha⁻¹; driving speed, 5 km h⁻¹)). Before the fertilizer was spread, measurements were made of the flow rate of the spreadable fertilizer through one bunker shutter. Fertilizer application simulations were performed using the discrete element simulation program EDEM. Research has shown that spreading the studied granular fertilizers at the dosage norm of 600 and 800 kg ha⁻¹ allows for the future expansion of the limits of spreading research using a spreading simulation. The most important directions of research would be the research of the spreader vanes’ shape, length, and rational settings positions, using the standard commonly used centrifugal spreader, after making small modifications of the spreader, to achieve that the spreader could spread larger norms of fertilizer or drive faster during spreading.