The use of metallurgical slag as a by-product of the steel industry in chemical melioration of acid soils

The effect of metallurgical slag application on chemical properties of the soils with limited productive ability (Stagnosol), as well as on chemical composition of cultivated vegetables (spinach and cabbage) as experimental crops, through the vegetative experiments performed in semi-controlled conditions, was studied. The longterm investigations were aimed to define the main parameters for possible wider usage of this secondary raw material (by-product of the steel industry, respectively) for chemical melioration and fertilization of acid soils in Serbia, as well as to indicate the justification of its application in agricultural practice. Generally, it was concluded that the studied metallurgical slag of the standardized chemical composition can be added to the acid soils toward amelioration the fertility without adverse effects.  http://dx.doi.org/10.5937/metmateng1403191

Sadržaj i odnos apsorbovanog Ca i Mg u serpentinitskim zemljištima Srbije

The contents of adsorbed Ca and Mg and their ratio (Ca/Mg) were researched in the serpentinite rankers of Serbia. The samples were taken from seven wider locations (Zlatibor, Kopaonik, Miroč, Maljen, Bukovi, Suvobor and Bubanj Potok) in the altitudinal belt between 100 and 1700 m. Altogether 32 soil profiles were opened and 47 soil samples were analyzed. The percentages of adsorbed Ca and Mg were determined by the method of the Atomic Absorption Spectrophotometry, after extraction with NH4-acetate. The study results show that the content of adsorbed Mg-ions in almost all analyzed samples was higher than the percentage of adsorbed Ca-ions, so their ratio (Ca/Mg) is less than 1. This Ca/Mg ratio has an unfavorable impact on the plant development and it was concluded that this is one of the basic reasons of the low productive capacity of the serpentinite rankers in Serbia.U radu su prikazani rezultati istraživanja sadržaja adsorbovanog Ca i Mg kao i njihovog odnosa (Ca/Mg) u serpentinitskim rankerima Srbije. Uzorci su uzeti iz sedam širih lokacija (Zlatibor, Kopaonik, Miroč, Maljen, Bukovi, Suvobor i Bubanj Potok) u visinskom pojasu između 100 i 1700 m nad.visine. Ukupno su otvorena 32 pedološka profila i analizirano je 47 uzoraka zemljišta. Sadržaj apsorbovanog Ča i Mg određen je metodom atomske aprsorpcione spektrofotometrije, posle ekstrakcije sa NH4-acetatom. Rezultati istraživanja su pokazali da je skoro u svim ispitanim uzorcima sadržaj apsorbovanog Mg-jona veći od sadržaja apsorbovanog Ca-jona, te je i njihov odnos (Ca/Mg) manji od jedinice. Ovakav odnos Ca/Mg se nepovoljno odražava na uspevanje biljaka i smatramo da je jedan od osnovnih uzroka niske produktivne sposobnosti serpentinitskih rankera Srbije

Uticaj prve rodne etaže na kvalitativno-kvantitativna svojstva semena soje

The aim of this study was to determine the effect of height of the first fertile floor on the qualitative and quantitative characteristics of soybean seeds. For qualitative traits the focus was on the energy of germination and seed germination of the studied genotypes investigated per soybean plant and the first fertile floor of the plant. Results of research indicated that there were significant differences between genotypes observed by morphological characteristics (plant height, height of first fertile floor, number of fertile floors, number of pods and seeds, seed weight, etc.) as well as qualitative properties (energy of germination and seed germination). Cultivar Gorštak, with genetically incorporated height of the first fertile floor (12.38 cm), was superior to other two genotypes. A similar trend was found in other morphological analyses. Based on energy of germination and seed germination of all fertile floors per plant, there were no significant differences between soybean genotypes. However, of paramount importance are the established values of these parameters relevant to the first fertile floor. Cultivar Gorštak had significantly higher energy of germination (90.46%) and total germination (91.00%) compared to the other two genotypes.Cilj istraživanja bio je utvrđivanje uticaja visine PRVE rodne etaže na kvalitativno-kvantitativna svojstva semena soje. Kod kvalitativnih svojstava akcenat je stavljen na energiju klijanja i ukupnu klijavost semena istraživanih genotipova posebno po biljci i prvoj rodnoj etaži. Sumiranjem rezultata istraživanja, utvrđene su značajne razlike između genotipova, posmatrano po morfološkim karakteristikama (visina biljaka, visina prve rodne etaže, broj rodnih etaža, broj mahuna i semena, masa semena i dr) kao i kod kvalitativnih svojstava - energije klijanja i ukupna klijavost semena. Sorta Gorštak sa genetički inkorporiranom visokom prvom rodnom etažom (12,38 cm) bila je dominantna u odnosu na druga dva genotipa. Sličan trend je utvrđen i kod drugih morfoloških analiza. Energija klijanja i ukupna klijavost semena svih rodnih etaža, posmatrano po genotipovima, nije pokazala značajne razlike. Međutim, od izuzetnog značaja su utvrđene vrednosti ovih parametara kada je reč o prvoj rodnoj etaži. Sorta Gorštak imala je vrlo značajnu veću vrednost energije klijanja (90,46%) kao i ukupnu klijavost semena (91,00 %) u odnosu na druga dva genotipa

Wear of diamond-coated cutting tool inserts upon machining of Al-12% Si and glass fiber/polyester resin composites

Results of the wear resistance of the diamond-coated cutting tool inserts upon machining Al-12% Si alloy and glass fiber/polyester resin composites are presented in this paper. The aim of this paper was to demonstrate the advantages of application of cutting tool inserts with the diamond coating over the conventional tungsten-carbide (WC) tools, and to obtain the cheaper serial production (shorter machining time) and satisfactory lifetime of the diamond cutting tool inserts. Surface roughness of the machined samples was measured for both as-received and diamond coated inserts. The diamond microstructure of undamaged part of inserts as well as the appearance of microstructure of diamond coated inserts after machining has been investigated. Results of the behavior of two regimes of preparation of diamond-coated inserts were compared and analyzed. Generally, the wear resistance of the diamond-coated cutting tool is superior over the conventional tool

Sadržaj teških metala u poplavnoj površinskoj vođi i poplavljenom zemljištu na teritoriji opštine Sečanj

This paper presents a part of the research related to the content of microelements and heavy metals in the floodwater and in the soil after the failure of the embankment on the river Tamiš in Rumania and the catastrophic flood during the second half of April 2005 on the territory of central Banal. Based on the results of the analyses of total contents of dangerous and harmful elements (copper, zinc, iron, manganese, cobalt, lead, cadmium, nickel and chromium) in the soil of the flooded area of central Banat, it can be concluded that the floodwater and flooded soil were not polluted by heavy metals, because the total concentrations of the study elements do not exceed the maximum admissible concentrations in any of the water or soil samples, according to the Regulation on the admissible values of dangerous and harmful substances in the soil and irrigation water and the methods of their analysis (Official Gazette of the Republic of Serbia 23/1994).U ovom radu prikazan je deo istraživanja koja se odnose na sadržaj mikeoelemenata i teških metala u poplavnoj vodi, i zemljištu nakon probijanja zaštitnog nasipa reke Tamiš u Rumuniji i katastrofalne poplave u drugoj polovini aprila meseca 2005.god. na teritoriji srednjeg Banata. Prema rezultatima izvršenih analiza ukupnog sadržaja opasnih i štetnih materija (bakra, cinka, gvožđa, mangana, kobalta, olova, kadmijuma, nikla i hroma) u zemljištu na poplavljenom području srednjeg Banata, može se zaključiti da poplavna voda kao i zemljište nisu bili zagađeni teškim metalima, jer ukupni sadržaj ispitivanih elemenata ni u jednom uzorku vode I zemljišta ne prelazi maksimalno dozvoljenu koncentraciju prema Pravilniku o dozvoljenim količinama opasnih i štetnih materija u zemljištu i vodi za navodnjavanje i metodama njihovog ispitivanja (Službeni Glasnik Republike Srbije 23/1994)

Mehanički sastav krečnjačkih crnica (kalkomelanosola) sa područja Rajca

Particle size distribution of different evolution phases of calcareous black soils were studied for the area of Rajac. Four subtypes of calcareous black soils (organogenic, organo-mineral, brownized and loessivized black soils) were singled out. Altogether 20 soil profiles were analyzed, i.e. 2 profiles of organogenic black soils, 7 profiles of organo-mineral black soils, 7 profiles of brownized black soils and 4 profiles of loessivized black soils. The study results indicate that the textural classes of all the analyzed subtypes of calcareous black soils are salty-clay loams, salty clay soils and clay soils.U radu su prikazani rezultati istraživanja mehaničkog sastava različitih evolucionih faza krečnjačkih crnica sa područja Rajca. Izdvojena su četiri podtipa krečnjačkih crnica (organogena, organo-mineralna, biaunizirana i lesivirana crnica). Ukupno je analizirano 20 peđoloških profila i to 2 profila organogene crnice, 7 profila organo-mineralne crnice, 7 profila braunizirane crnice i 4 profila lesivirane crnice. Rezultati istraživanja pokazali su da svi ispitani podtipovi krečnjačkih crnica po teksturnoj klasi pripadaju praškasto-glinovitim ilovačama, praškastim glinušama i glinušama

Specifičnosti transformacije mineralnih oblika azota u kiselim zemljištima

Investigations were performed on soils of different acidity, ranging in the pH interval 4.65-5.80 (in water). Changes of the mineral nitrogen forms in the examined soils were studied by applying short-term incubation experiments performed under aerobic conditions, with a humidity of 30 % and a temperature of 20°C, both with and without the addition of 100 and 300 ppm NH4-N. The results of the incubation experiments showed that retarded nitrification was present in all the examined soils. Increased and toxic quantities of nitrites (35.7 ppm) were formed during the incubation, which remained in the soil solution for several days, and even weeks, in spite of favorable conditions of moisture, aeration and temperature for the development of the process of chemoautotrophic nitrification. Decelerated chemoautotrophic nitrification was the source of the occurrence of nitrite in the examined less acid soil (soil 1), while in soils of higher acidity (soils 2 and 3) after addition of 100 and 300 ppm NH4-N, nitrite occurred due to chemical denitrification (chemodenitrification). Nitrites formed in the process of chemodenitrification underwent spontaneous chemical oxidation resulting in nitrate formation (chemical nitrification). The content of mineral nitrogen (NH4 + NO3 + NO2-N) decreased during the incubation period, proving gaseous losses from the examined soils. Application of lower doses of nitrogen fertilizers could decrease nitrogen losses by denitrification as well as the occurrence of nitrite in toxic quantities in the investigated pseudogley soil.Istraživanja su obavljena na zemljištu tipa pseudoglej iz okoline Šapca. Ispitivana zemljišta spadaju u grupu kiselih i jako kiselih zemljišta. Promene mineralnih oblika azota su praćene pomoću kratkotrajnih inkubacionih ogleda (vlažnost 30 % i temperatura 20 °S), sa i bez dodatka 100 i 300 ppm NH4-N. Tokom inkubacije utvrđene su povišene i toksične količine nitrita, koje su se u zemljišnom rastvoru zadržavale više dana i nedelja. Utvrđene količine nitrita su se javljale kao posledica usporene biološke nitrifikacije (kod manje kiselog zemljišta), dok su pri dodatku 100 i 300 ppm NH4-N one nastajale u procesu hemodenitrifikacije. U ispitivanim zemljištima se odvijala i spontana oksidacija nastalih nitrita hemijskim putem (hemijska nitrifikacija). Da bi se smanjili gubici azota procesom denitrifikacije i stvaranje toksičnih količina nitrita na pseudoglejnom zemljištu se može preporučiti primena nižih doza azotnih đubriva u odnosu na doze koje se primenjuju kod neutralnih i alkalnih zemljišta

Labile fractions of soil organic carbon in mollisols from different climatic regions

Characterization of Labile Fractions of Soil Organic Carbon in Mollisols from different climatic regions. The research studied the potential mineralization and characterization of labile SOM of different types of Mollisols: Hapludolls, Argiudolls, Calciustolls, and Haplustolls. Labile C fractions distributed oppositely than total SOC and were the greatest in Calciustolls and the lowest in Hapludolls. The amount of soil microbial biomass C (MBC) was significantly higher in dry than in wet regions. The highest amount of light fraction C was in dry-thermic followed by dry-frigid, and the least amount was in wet regions. Dry regions were able to retain a higher level of labile C than the moist regions, due to a slower annual decomposition rate

Sadržaj mobilnog nikla u serpentintskim rankerima Srbije

The paper presents the study results of the content of mobile Ni in serpentine rankers of Serbia. The samples were taken from seven wider locations (Zlatibor, Kopaonik, Miroč, Maljen, Bukovi, Suvobor and Bubanj Potok) in the altitudinal zone between 100 and 1700 m. Extraction of mobile Ni was conducted with 1.0 N HC1, and its contents were determined by the method of atomic absorption spectrophotometry. The results of analysis show that around 70% of the tested samples contain 200 - 600 mg/kg of mobile Ni, which is far above the admissible quantities for the total Ni in the soil. Therefore, the serpentine rankers of Serbia contain phytotoxic concentrations of mobile Ni, which is one of the main reasons of poor growth of plants on these rankers.U radu su prikazani rezultati istraživanja sadržaja mobilnog Ni u serpentintskim rankerima Srbije. Uzorci su uzeti sa sedam širih lokacija (Zlatibor, Kopaonik, Miroč, Maljen, Bukovi, Suvobor i Bubanj Potok) u visinskom pojasu između 100 i 1700 m nad.visine. Ekstrakcija mobilnog Ni izvršena je sa 1.0 N HCl, a njegov sadržaj određen metodom atomske apsorpcione spektrofotometrije. Rezultati analiza pokazuju da oko 70% ispitanih uzoraka sadrži 200 - 600 mg/kg mobilnog Ni, što je mnogo vise od dozvoljenih količina koje se daju za ukupni Ni u zemljištu. Prema tome, serpentintski rankeri Srbije sadrže fitotoksične koncentracije mobilnog Ni, što je jedan od bitnih razloga lošeg uspevanja biljaka na njima

The use of metallurgical slag as a by-product of the steel industry in chemical melioration of acid soils

The effect of metallurgical slag application on chemical properties of the soils with limited productive ability (Stagnosol), as well as on chemical composition of cultivated vegetables (spinach and cabbage) as experimental crops, through the vegetative experiments performed in semi-controlled conditions, was studied. The longterm investigations were aimed to define the main parameters for possible wider usage of this secondary raw material (by-product of the steel industry, respectively) for chemical melioration and fertilization of acid soils in Serbia, as well as to indicate the justification of its application in agricultural practice. Generally, it was concluded that the studied metallurgical slag of the standardized chemical composition can be added to the acid soils toward amelioration the fertility without adverse effects