Model ocene kvaliteta obrade na bazi statistike zemljišta

Tillage exposes the soil to different mechanisms of direct or indirect mechanical decomposition, crucially changing its structure. Among others, a possible initial approach in controlling the quality of each specified operation and complete tillage process assumes establishing the functional relations between the operational parameters of applied mechanization and resulting probability density distribution of soil particle sizes. In this paper, the log-hyperbolic function is introduced and experimentally verified in describing the post-tillage soil particle sizes probability density distribution. Cultivation includes a variety of mechanical soil decomposing mechanisms. Consequently, quality controll of a tillage concept incorporates the analysis of resulting soil particle sizes distribution, usually different from the normal Gaussian model. Following the common practice, shapes of these distributions are quantified in the paper by skewness S (SS) and flatness F (SF) factors. Data from five experiments gave clear relationships F=F(S) and SF=SF(SS), that might be useful in modelling and controlling the tillage quality.Obrada izlaže zemljište uticaju različitih mehanizama fizičke dekompozicije, direktno ili indirektno, suštinski menjajući njegovu mehaničku strukturu. Između ostalih, jedan od mogućih pristupa u analizi kvaliteta svake predviđene operacije i procesa obrade u celini svodi se na uspostavljanje funkcionalnih veza između operativnih parametara primenjene mehanizacije i rezultujuće raspodele čestica obrađenog zemljišta. U ovom radu je, u svojstvu preliminarnog koraka, predložena i eksperimentalno potvrđena primenljivost log-hiperboličke funkcije za opisivanje raspodela veličina čestica obrađenog zemljišta. Obrada zemljišta je mehaničko usitnjavanje zemljišnih frakcija. Stoga je kontrola kvaliteta oranja koncept koji podrazumeva analizu veličina čestica zemljišta i funkciju njihove raspodele koja je obično drugačija od normalane (Gausovog modela). Sledeći opštu praksu, u izvesnim situacijama koriste se faktori asimetrije S (SS) i zaravnjenja F (SF). U radu se anliziraju rezultati pet eksperimenata gde se koriste faktori F=F(S) i SF=SF(SS), a rezultat modeliranja bi koristio za kontrolu kvaliteta rada

Analiza uticaja uslova eksploatacije traktora na njegovu pouzdanost

Tractors exploitation conditions are very complex. This demands different working regimes where each of these are manifested through reactive forces and moments influence on tractors subsystems. These influences are manifested through loads that need to be in acoordance with static and dynamic streighnest, material "tirenes" and wear resistances in order to have desired level of reliability. Considering the fact that material "tirenes" curves can serve only for evaluating the time of exploitation for an element in tractor subsystem, for more precise determination of period of usage an estimation of spares for certain exploitation conditions is needed. This paper deals with their clasification in to six categories concerning the exploitation plot conditions and their influence on tractors.Uslovi eksploatacije traktora su brojni i raznovrsni što zahteva različite režime rada traktora, a svaki od njih se manifestuje kroz uticaj sila i momenata na njegove podsisteme i elemente. Opterećenja koje izazivaju ove sile treba da budu usaglašena sa statičkom čvrstoćom, zamorom i otpornosti na habanje elemenata kako bi se postigao zahtevani nivo pouzdanosti. Kako se na osnovu zamornih krivih dobijenih laboratorijskim ispitivanjem može samo oceniti vek nekog elementa u konstrukciji traktora, a ne i tačno odrediti, za preciznije određivanje trajnosti elemenata predlaže se provera rezerve za određene uslove eksploatacije. S obzirom na brojnost i raznovrsnost uslova eksploatacije, u ovom radu je izvršena njihova klasifikacija u šest kategorija na osnovu karakteristika podloge po kojoj se traktor kreće, odnosno uticaja podloge na različita radna opterećenja

CALCULATIONS IN MILK PRODUCTION ON FAMILY FARMS

Milk production in Serbia is mostly practiced by family farms characterised by small herds of cattle, low milk yield per cow, high feed costs, and variable milk quality. Both small and specialised farms housing up to 10 lactating cows are often unable to maintain their cost-effectiveness. A study was conducted on two family farms i.e. farm A and farm B during 2013-2015 to record production data. Total production value, variable costs and contribution margin were calculated. For easy comparison between the farms, results were expressed per lactating cow. The sensitivity analysis of milk yield and farmgate milk prices showed that, at low values, contribution margins were more sensitive to changes in farmgate milk price. Through subsidies and premium payments, family farms maintain the cost-effectiveness of their production. However, small-scale producers are facing the largest threat, given low milk yields per cow and poor milk quality

Uticajni faktori navodnjavanja kišenjem na nagibima

Intensive plant production can not be imagined without irrigation. Support to this fact is that 18% of the total arable land in the world is irrigated, and the agricultural production from this area is equal to the total production of agricultural products from the rest of non irrigated area, which is 6 times larger. Irrigation in our country is under the real possibilities and needs, is provided on small areas and doesn’t influence significantly the agricultural production. Irrigation with raining on the slopes is very important because of potential of the hilly region in Serbia. Specific limitations of work on slopes, firstly because of protection from erosion, are directly influencing the selection and working regime of irrigation system.Intenzivna biljna proizvodnja nezamisliva je bez navodnjavanja. U prilog ovoj činjenici ide i podatak da se u svetu navodnjava 18% ukupno obradivih površina sa kojih se dobija isto onoliko poljoprivrednih proizvoda kao sa ostalih oko 6 puta većih nenavodnjavanih površina. U našoj zemlji navodnjava se ispod realnih mogućnosti i stvarnih potreba, obavlja se na malim površinama i ne utiče posebno na obim poljoprivredne proizvodnje. Navodnjavanje kišenjem na nagibima ima veliki značaj obzirom na potencijal brdskog područja u Srbiji. Specifičnosti uzrokovane ograničenjima u radu na nagibu, pre svega sprečavanju izazivanja erozije, direktno se reflektuje na izbor i režim rada sistema za navodnjavanje

speed

Introduction of new generation harvesters is analyzed through efficiency, losses and quality of harvested crop. Purpose of the investigation is analysis of new generation harvesters working parameters in corn harvesting. On this base will be defined possibilities of improvement of efficiency and productivity, as well as decrement of fuel consumption. Results of investigation have shown the fallowing parameters: - at harvester A – fuel consumption was 14.04 l/ha, or 58.97 l/h, with the efficiency of 4.2 ha/h and average working speed of 8.0 km/h. - at harvester B – fuel consumption was 22.50 l/ha, or 45.82 l/h, with the efficiency of 2.065 ha/h and average working speed of 6.4 km/h. Efficiency coefficient of the harvester is 0.7, but it can be significantly increased with better harmonizing of working regime and working conditions.Uvođenje savremenih kombajna nove generacije u tehnološki proces ubiranja poljoprivrednih kultura, sagledava se sa aspekta učinka, gubitka i kvaliteta ovršene mase Cilj ispitivanja je analiza parametra i pokazatelja rada kombajna nove generacije u uslovima ubiranja kukuruza, na osnovu čega će se sagledati mogućnosti povećanja učinka, produktivnosti rada, i smanjenja utroška goriva po jedinici proizvoda. Na osnovu ispitivanja utvrđene su vrednosti relevantnih parametara i pokazatelja: - kod kombajna A- potrošnja goriva od 14,04 l/ha, odnosno 58,97 l/h pri učinku od 4,2 ha/h i prosečnoj brzini kretanja od 8,0 km/h. - kod kombajna B- potrošnja goriva od 22,50 l/ha, odnosno 45,82 l/h pri učinku od 2,065 ha/h i prosečnoj brzini kretanja od 6,4 km/h. Stepen iskorišćenja oba kombajna iznosi 0,7, s tim da bi se vrednost ovog stepena mogla znatno povećati sa boljom usaglašenosti režima i uslova rada

Uticaj fizičkih osobina mineralnih đubriva na efikasnost aplikacije

Proper choice and efficient utilization of various technological-technical application systems still has a significant importance concerning ecology, energy and economy in agriculture. Due to the predominant practice of using granulated mineral fertilizers an analysis of mineral fertilizer processing including its production, manipulation and application was made. Physical and mechanical characteristics of mineral fertilizers and fertilizer reaction with the application systems are of outmost importance in fertilizer application system choice. Successful utilization of mineral fertilizers predominantly depends upon the interaction between mineral fertilizers physical-mechanical characteristics and the appropriate type of spreader. The aim of this paper was to analyze working quality of two centrifugal spreaders in relation to physical properties of applied fertilizers in the conditions of seed-bed preparation for corn seeding.Značaj mineralnih đubriva u savremenoj biljnoj proizvodnji kako u agrotehničkom i ekološkom pogledu aktuelizuje izbor i efikasno korišćenje tehnološkotehnoloških sistema aplikacije. Dominantna praksa korišćenja čvrstih mineralnih đubriva (granulata) nameće celovitu analizu procesa mineralnih đubriva koji podrazumeva proizvodnju, manipulaciju i aplikaciju. Interakcija fizičko-mehaničkih svojstava mineralnih đubriva i tipa rasipača od presudnog je značaja za uspešnost primene ovih đubriva. Cilj ovog rada bila je analiza kvaliteta rada centrifugalnih aparata u kontekstu fizičko-mehaničkih osobina primenjenih đubriva. Ispitivanjem su obuhvaćena dva rasipača centrifugalnog tipa tokom predsetvene pripreme za setvu kukuruza

Energetski aspekti navodnjavanja kišenjem

This research has included two different raining irrigation systems, both rain gun and mobile linear system. According to the calculations, can be concluded that those two systems work with different pressures, which causes different losses in the pipe line. Reason for significantly higher losses (1,7 bar) and consequently higher energy consumption (131 kW/ha) at self propelled rain gun is that water energy in this case is used for rolling the hose and movement of the sprinkler. At mobile linear system, the movement is propelled by electro motors and, at the same time, this system works with significantly lower pressures, which means lower energy consumption, as well (45,28 kW/ha).Istraživanjima su obuhvaćena dva različita sistema navodnjavanja kišenjem i to samohodni kišni top i mobilni linearni sistem. Na osnovu proračuna može se zaključiti da ova dva sistema rade sa različitim pritiscima, a samim time i gubitci u cevovodu su različiti. Razlog znatno većim gubitcima (1,7 bar), a time i većoj potrošnji energije (131 kW/ha) kod samohodnog kišnog topa leži u činjenici da se energija vode u ovom slučaju koristi za namotavnje creva odnosno za kretanje prskača.Kod mobilnog linearnog sistema za kretanje se koriste elektro motori, a sem toga ovaj sistem radi sa znatno nižim pritiscima pa je samim time i potrošnja energije manja (45,28 kW/ha)

Monitoring pašnjaka zapadno-kazahstanske oblasti (primer Karatobinskog rejona)

Topic of this research are pastures in the Karatobin region that are parts of the Kaspijan valley desert and semi-deserts. In this paper degradation of the pastures, caused by industry activities is analyzed. Based on the results obtained from the geoinformation research, the degree of pasture degradation in the experimental field of Karatobe (West-Kazkhstan region) is given. Obtained results give the possibility for easy and precise evaluation of the pasture conditions in the region.Predmet istraživanjarada su pašnjaci Karatobinskog rejona Zapadno- Kazahstanske oblasti koji čine deo pustinja i polupustinja Kaspijske nizije-ravnice. Takođe, u radu su razmotreni i procesi degradacije pašnjaka uzrokovanih intenzivnom privrednom aktivnošću. U radu je na osnovu rezultata geoinformacionih istraživanja iznet stepen degradacije pašnjaka na oglednom poligonu Karatobe, Zapadno- Kazahstanske oblasti. Dobijeni parametri omogućavaju brzu i tačnu ocenu stanja pašnjaka u regionu

Operacionalizacija ekonomičnosti potrošnje goriva traktora

Fuel consumption in agriculture is on very high level. Even a small percentage of lowering fuel consumption can contribute to more successful management of agricultural enterprises. Reduced fuel consumption will, also, be a mean of fossil fuel resources preservation and ecology friendlier agriculture production. There are known methods for reducing fuel consumption abut are not fully used. This paper presents results of using known methods in operationalisation of fuel consumption economy. The results are given for tractors with diesel motors and common fuel supply systems.Poljoprivreda je veliki potrošač dizel goriva pa bi i malo procentualno smanjenje značilo veliku uštedu. To bi vodilo ka uspešnijem poslovanju poljoprivrednih preduzeća ali još značajnije je da bi se time doprinelo očuvanju ograničenih resursa fosilnih goriva kao i smanjenju zagađenja okoline. Metode za smanjenje potrošnje goriva su uglavnom poznate ali se nedovoljno primenjuju. Zbog toga se u ovom radu kroz plansku primenu poznatih metoda operacionalizuje ekonomičnost potrošnje goriva kod traktora sa dizel motorima koji imaju klasičan sistem snabdevanja gorivom

Struktura zemljišta nakon dopunske obrade

Tillage exposes the soil to different mechanisms of mechanical decomposition, which crucially change its structure. Possible approach in controlling the quality of each specified operation and complete tillage process assumes establishing the functional relations between the operational parameters of applied mechanization and resulting mass probability density function of soil particle sizes. Based on experimental data from three independent experiments, the appropriate nonlinear relationships between the mass probability density functions of different soil fractions and particle diameters of these fractions. Calculations are based on the least squares fitting method. These expressions can facilitate modeling and prediction of soil fractions distribution and tillage quality control.Mehanizovana obrada izlaže zemljište uticaju različitih mehanizama mehaničke dekompozicije, suštinski menjajući njegovu strukturu. Mogući pristup analizi kvaliteta svake pojedinačne operacije i procesa obrade u celini podrazumeva uspostavljanje funkcionalnih veza između radnih parametara primenjene mehanizacije i rezultujuće masene raspodele frakcija obrađenog zemljišta. Na osnovu eksperimentalnih podataka iz tri nezavisna eksperimenata, formulisane su odgovarajuće nelinearne veze funkcije masene gustine verovatnoće različitih frakcija obrađene oranice i pripadajućih prečnika čestica tih frakcija. Proračun je zasnovan na metodi najmanjih kvadrata. Dobijeni izrazi mogu olakšati modeliranje i procenu veličina frakcija zemljišta, kao i kontrolu kvaliteta mehanizovane obrade oranice