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.

In recent years, the European countries recycle only 5−7% of bio-waste. One activity of the biological waste disposal is granulation. The production of fertilizer from animal manure with supplement represents an important area of environmentally friendly bio-fertilizer production. This paper presents an investigation of estimation manure compost physical-mechanical properties for reuse of organic waste − cattle and cow manure, sugar production waste − molasses through new technology pellets production and of granulated fertilizer impact on soil. The experimental manure samples produced by industrial methods and samples produced in the laboratory from the time period of 2014 to 2017 were investigated. The following physical – mechanical characteristics were estimated: biometric indicators (dimensions, mass), volume and density of raw material and pellets, material and pellet’s humidity and pellets strength. Experiments results have shown that the difference in limit strength between experimental and industrial organic compost pellets was about 5%. Experiments of fertilizers on the impact on soil shown that the amount of nutrients added to the soil depends on the rate of the granulated compost fertilizer. As the norm increases, organic carbon, humus, mobile phosphorus and potassium increase in soil. Increases in soil fertility, improved agrochemical properties, soil organic matter accumulation and humus increase. Granulated compost fertilizers have no effect on soil acidity. The presented results could be helpful to the development of the fertilizing process by the granulated compost fertilizer for improvement of soil quality in small farms.

Precise and environmentally friendly fertilization is one of the most effective agrotechnical measures to improve crop yield, crop quality, and environmental sustainability. The aim of this study was to determine the uniformity of spreading of organic fertilizers on the soil surface at different flows by evaluating the influence of the physical and mechanical properties of the fertilizers. The physical properties of organic fertilizers have been found to have a significant impact on the uniformity of fertilizer distribution. The investigation of fertilizer properties showed that the average moisture content of meat and bone meal granular fertilizers was 8.6 ± 0.2%, of cattle manure granular fertilizers—14.9 ± 1.5%, of dry lime—9.4 ± 0.1%, of wet lime—17.0 ± 1.1%, and of manure—66.7 ± 6.9%. It was found that the granules of cattle manure were more evenly spread on the soil surface (Gaussian coefficient 0.46) than the granules of meat and bone meal (g₂ = 7.11). At the same time, manure was found to be most evenly distributed on the soil when dry lime was spread more evenly than wet. Simultaneously, it was revealed that the physical properties of the fertilizer, such as higher moisture, lower mass, granule length, and width, affected the uniformity of fertilizer distribution on the soil surface.

In order to extend grain’s storage time and ensure its quality, it is necessary to sort and clean it. The aim of this study was to justify the rational shape of the sorting chamber and the optimal technological parameters for the sorting of wheat grains in airflow. This study used newly designed grain sorting chambers with constant, widening, and narrowing cross-sections for the airflow sorting of “Skagen” wheat grain. The aerodynamic properties of wheat grains were investigated when moisture was at 14 ± 2.0%. The grain flow rate in the chambers varied from 4 to 12 kg min⁻¹ every 2 kg min⁻¹. In addition, the airflow velocity varied from 8 to 12 m s⁻¹ every 1 m s⁻¹. The tilt angle of the constant cross-section camera was increased to 5°. Experimental studies have determined a terminal airflow velocity of 11.53 m s⁻¹ for wheat grains. At the terminal airflow velocity, the grain flight coefficient was obtained to be about 0.074. These studies showed that the narrowing chamber is preferable for lower grain flow rates compared to the constant cross-section of the chamber. The widening chamber requires a lower airflow velocity to achieve the same performance and quality as the other chambers.