ENGINEERING FOR RURAL DEVELOPMENT Jelgava, 26.-28.05.2021. 412 PHYSICAL MECHANICAL PROPERTIES EVALUATION OF EXPERIMENTAL GRANULATED POULTRY MANURE FERTILIZER Ramunas Mieldazys, Egle Jotautiene, Algirdas Jasinskas Vytautas Magnus University, Lithuania ramunas.mieldazys@vdu.lt, egle.jotautiene@vdu.lt, algirdas.jasinskas@vdu.lt Abstract. Currently there are searches for new and more rational ways to use agricultural organic waste for new forms of energy, creating fertilizers and other products. One of biodegradable waste management ways is raw material granulation, as processing of recyclable materials into compressed organic products. According to the EU legal requirements manure is considered to be waste the livestock owner has to account for and eliminate using as crop fertilizer and not polluting the environment. Poultry manure granulation can increase the bulk density, improve storability, reduce transportation costs, and make these materials easier to handle using the existing handling and storage equipment. Granulation process parameters and factors affecting the manure-based material of organic granular fertilizer physical-mechanical properties were investigated. Poultry manure raw material samples were dried naturally till about 46% moisture content. Before granulation samples were dried artificially till about 15% moisture content. There were prepared 5 experimental poultry manure samples and granulated mixtures of manure waste with molasses and lime sludge adds in laboratory conditions. For granule production a small capacity 7.5 kW granulator was used with a horizontal 6 mm matrix. During the research, the physical – mechanical characteristics were estimated: biometric indicators (dimensions, mass), raw material and granule volume and density, moisture content and granule strength. The aim of this work is to investigate the granular organic fertilizer with relevant physical-mechanical properties which influence the product quality. Keywords: poultry manure; granules; physical-mechanical properties; density, granule strength. Introduction With reference to Lithuania, according to official statistics, from 2015 to 2019 a total of poultry 11 836 292 heads were reared [1]. The number of most popular animals at the beginning of the year is presented in Table 1. The number of poultry tends to increase, and such concentration of livestock farming activity makes it critical from the environmental points of view. Such farms are becoming larger, and the number of farmed poultry is increasing. According to Polish scientists, quantities of poultry manure generated in poultry production are expected to continue to grow [2]. Therefore, it is necessary to improve the manure management technologies in line with the required reduction of livestock farming environmental pressure [3]. Table 1 Number of poultry at the beginning of 2015–2019 [1] Animal kind 2015 2016 2017 2018 2019 Poultry (head) 10 218 417 93 695 63 10 098 885 10 405 427 11 836 292 The amount of poultry manure varies according to the specifics of the poultry type: 120 kg for layer chickens, 80 kg for meat chickens, 200-350 kg for turkeys and 150 kg for ducks (1000 birds per day generate the amount of manure in kg) [4; 5]. According to scientists, the speed of producing manure waste in poultry farming consists of about 40-45 t of waste for 1000 birds in a year [6]. Poultry farming has a significant impact on the environment and should be improved as part of a proper waste management system. There is a number of technologies for processing poultry manure into added value products or recovered energy, however, still the most common way of processing poultry manure is biological treatment, such as composting or anaerobic digestion, but still the problems related to the excessive emission of ammonia, and thus nitrogen loss, and odors have not been sufficiently solved [2]. One of manure management technologies trend is to process poultry manure into valuable granular fertilizing products. High levels of nutrients, nitrogen, potassium and phosphorus amounts in poultry litter indicate suitability for fertilizer and soil improver production [2; 7]. Granular poultry litter is more useful and suitable as an organic fertilizer compared to the not treated raw form [8]. Therefore, the production of granules from poultry manure and litter, as they contain macro and micro nutrients, has a great potential for agricultural applications, which is enhanced by their satisfactory mechanical quality, especially the mechanical granule strength [2; 9; 10]. Granulated chicken manure positively affected soil moisture retention, infiltration, and increased the aggregate stability [11]. By analysing the results DOI: 10.22616/ERDev.2021.20.TF085