Increased demand for food production, influenced by the constant growth of population, resulted in the agricultural production systems that are more energy and economy intensive. The aim of this study was to evaluate the energetic and economic efficiency of sugar beet and wheat production. Attention was given to the fertilizer usage and its share in energy consumption since it can amount to 50%. Data show that energy input in wheat production was 5.84 MJ·kg−1 and in sugar beet it was 0.93 MJ·kg−1. The highest share of energy input both in wheat and sugar beet was observed for fertilizers, 52.45% and 46.70%, respectively. Economic analysis has shown that wheat production is a low profitable production with a net return of only 20.69 USD·ha−1, in comparison with sugar beet production with a net return of 513.53 USD·ha−1. Costs related to the fertilizer use prevailed in total variable and total production costs. Economic analysis has also shown that the benefit-to-cost ratio was higher in sugar beet production (1.33) compared to wheat production (1.03). Furthermore, it was determined that these economic indicators were less sensitive in sugar beet production than in wheat production regarding the variation of fertilizer.

Mineral fertilizers have a pivotal role in contemporary agricultural production, especially when seeking to exploit the full biological potential of crops. This paper presents the results of a three-year experiment on the distribution uniformity of different mineral fertilizer application systems. One of the objectives in this study was to define the physical and mechanical properties of four different types of mineral fertilizers and examine their changes during storage, transportation and application. A total of four fertilizers were taken into account: UREA, CAN, MAP and NP. The main physical properties, i.e. particle size, particle size distribution, friction coefficient, angle of repose and particle resistance, were analyzed on samples collected from the storage, the trailer (prior to application) and the field (after application). The results obtained show that fertilizers with a particle size distribution of 3.3 to 4.75 mm exhibit higher values of the angle of repose, friction and resistance. The lowest value of the angle of friction (17.53 0 ) was observed in the UREA fertilizer after application, whereas the highest angle of friction (24.37 0 ) was measured in the MAP fertilizer obtained from the storage. The values of the static repose angle varied depending on the fertilizer type and the place of sampling (storage, trailer or field). The lowest value of the static repose angle (30.34 0 ) was measured in the MAP fertilizer after application, whereas the highest static repose angle (36.91 0 ) was measured in the NP fertilizer from the storage. The NP fertilizer exhibited the highest value of the dynamic friction angle, whereas the lowest value of the dynamic friction angle was calculated for the UREA fertilizer. The NP fertilizer particles showed the highest resistance, whereas the UREA fertilizer particles were most susceptible to breakage. REZIME Sаvremenа poljoprivrednа proizvodnjа se ne može zаmisliti bez primene đubrivа, posebno sа аspektа boljeg korišćenjа biološkog potencijаlа rodnosti gajenih biljаkа. U radu je prikazan deo rezultata trogodišnjih ispitivanja tehničko-tehnološkog sistema aplikacije mineralnih đubriva različitim tipovima centrifugalnih rasipača. Jedan od ciljeva istraživanja bio je i određivаnje fizičkomehаničkih osobinа rаzličitih tipova minerаlnih đubrivа, njihovih promena tokom samog procesa aplikacije i njihovog uticaja na kvalitet same aplikacije. U istraživanje su uključena četiri tipa mineralnih đubriva i to UREA, KAN, MAP i NP.Dobijeni rezultati tokom ispitivanja fizičko-mehaničkih osobina primenjivanih mineralnih đubriva pokazuju da đubriva koja imaju najveći procenat granula prečnika između 3,3 mm i 4,75 mm imaju najveće uglove trenja i nasipanja, kao i dobru otpornost prema lomu granule. Vrednosti ugla trenja su značajno varirale u zavisnosti od tipa đubriva i mesta uzorkovanja. Najniža vrednost, 17,53 o je zabeležena kod UREE nakon aplikacije a najviša, 24,37 o kod đubriva MAP iz skladišta na imanju. Vrednosti statičkog ugla nasipanja su takođe statistički značajno va...

The efficiency of primary agricultural production is under constant analysis relative to energy, economy and ecology. Notwithstanding technological innovations in agricultural production, engineers and researchers are still seeking to create a production system that would render the primary agricultural production more energy efficient and ecologically sustainable.The purpose of this paper is to examine the energy consumption and efficiency of crop production with an emphasis on the importance of mineral fertilizers and their influence on the overall energy consumption. The results obtained indicate that mineral fertilizers claim a share of the total energy consumption in crop production ranging from 40.53 % in sunflowers to 55.19 % in maize. A statistically significant correlation was found between the energy inputs for fertilizers and crop yields. The regression analysis performed showed a positive correlation between the energy inputs for fertilizers and yields in all the crops considered, with the exception of wheat.

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The equipment and engagement of tractor and attached machines were examined on the example of the average family farm Šiljić in Serbia. The research was performed on a registered agricultural farm in the village of Selevac, municipality of Smederevska Palanka. The family farm Šiljić has a total of 5,4 ha of used agricultural land. In production season 2019/2020 wheat was sown on 2 ha and 1 ha of maize, sunflower and triticale each. On the area of 0,4 ha is a backyard and garden. The farm owns a tractor IMT-558, a plough, a disc harrow, a harrow, a sprayer and a trailer, purchased in 1979. The old machinery is in use. The registered family farm Šiljić is insufficiently equipped with mechanization. With a two-axle tractor with a power of 42.65 kW and 5 attached machines cultivates 5.4 ha, so the energy equipment is 8.5 kW/ha. The tractor is mostly engaged in the production of corn 10,0 h/ha, sunflower 9,5 h/ha, triticale 8,33 h/ha and the least is wheat 7,41 h/ha of effective work. On the farm Šiljić, on the area of 5 ha, out of a total of 42,66 hours of work, the tractor was mostly used in the basic tillage 17,0 h or 3,1 h/ha. The tractor is also engaged in pre-sowing soil preparation with a disc harrow 9 h (1,8 h/ha) and a harrow 7 hours (1,4 h/ha), in a transport 5,33 h (1,07 h/ha), in the application of pesticides with a sprayer 4,33 h (0,87 h/ha). In addition to the total effective work in the implementation of certain agro-technical measures in the production of field crops, the tractor was hired at 7,30 hours to leave and return from the plot (auxiliary working hours). Fuel consumption in basic tillage was 18 l/ha, in presowing preparation with a disc harrow 10 l/ha, harrow 5 l/ha and 5 l/ha in the application of pesticides and transport of products.