Soil organic carbon fractions in different land use systems of Chernozem soil

The relationship between soil carbon fractions in Chernozem soils was assessed in soil samples of three different environments: arable soil, grassland and oak for­est. Grassland and oak forest had higher soil organic carbon (SOC), carbon soluble in hot water (HWC), particulate organic carbon (POC) and mineral-associated carbon (MOC) than the arable soil. The POC/MOC ratio was lowest in arable soil, indicating a smaller carbon pool for microbial turnover. POC increases with higher total SOC, indicating that the pres­ervation of organic matter depends on the renewal of labile fractions. Our results showed that fertilization had active role in soil carbon stabilization, while crop rotation had less effect on a soil carbon turnover. Our result could contribute to the better understanding of SOC fractions composition and relevance in Chernozem soil, thus could help in selection of cropping management systems for SOC preservation. [Projects of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR031072 and Grant no. TR031073

Efekat biouglja na morfološka svojstva kukuruza i soje

This paper analyses the effects of the biochar application morphological traits in maize and soybean under semi-controlled conditions. During the study, the increasing doses of biochar (0%, 0.5%, 1, 3, and 5%) were incorporated in three soil types: Alluvium, Humogley and Chernozem to determine plant height and shoot weight. The experiment was set up as fully randomized design with three repetitions. The plants were grown in pots of 5 l with controlled watering and N fertilization. The research results have shown that there are differences in terms of biochar effects on soils. The greatest effect on plant height and shoot weight was obtained when the biochar was applied to Humogley soil and lower effects were found on the Alluvium soil. The increase in aboveground mass of maize and soybeans was significantly conditioned by adding different doses of biochar. Based on these results, it can be concluded that adding biochar can significantly affect the growth of plants. This is a consequence of the changes it causes in soil, which requires further tests to complement the current findings.U radu je ispitivan uticaj primene biouglja na morfološka svojstva kukuruza i soje u polukontrolisanim uslovima. Primenjene su rastuće doze biouglja na tri tipa zemljišta: aluvijum, černozem i humoglej i praćena je visina biljaka i masa nadzemnog dela. Ogled je postavljen po randomiziranom rasporedu sa tri ponavljanja u sudove zapremine 5 litara, a setva je izvršena u mesecu maju. Rezultati istraživanja su pokazali da postoje razlike u pogledu ispitivanih zemljišta i primenjenih doza biouglja. Najbolji efekat je dobijen kada je biougalj primenjen na zemljište humoglej a najmanji uticaj primene biouglja je utvrđen na aluvijalnom zemljištu. Porast nadzemne mase kukuruza i soje bio je u značajnoj meri uslovljen dodavanjem različitih doza biouglja. Na osnovu dobijenih rezultata može se zaključiti da dodavanje biouglja može značajno uticati na porast biljaka koji je posledica promene koje on izaziva u svojstvima zemljišta, ali da je neophodno nastaviti dalja ispitivanja kako bi se upotpunila dosadašnja saznanja. Utvrđeno je da su ispitivana svojstva kod soje ispoljila veću reakciju na primenu biouglja u odnosu na kukuruz

Distribution and forms of iron in the vertisols of Serbia

Soil of arable land and meadows from the Ap horizon, taken from ten different localities, were investigated for different forms of Fe, including total (HF), pseudo-total (HNO3), 0.1 M HCl extractable and DTPA (diethylenetriaminepentaacetic acid)-extractable. A sequential fractional procedure was employed to separate the Fe into fractions: water soluble and exchangeable Fe (I), Fe specifically adsorbed with carbonates (II), reducibly releasable Fe in oxides (III), Fe bonded with organic matter (IV) and Fe structurally bonded in silicates (residual fraction) (V). The soil pH, cation exchange capacity, and size fractions (clay and silt) had a strongest influence on the distribution of the different forms of Fe. The different extraction methods showed similar patterns of the Fe content in arable and meadow soils. However, the DTPA iron did not correspond with the total iron, which confirms the widespread incidence of iron-deficiency in vertisols is independent of the total iron in soils. The amount of exchangeable (fraction I) and specifically adsorbed (II) iron showed no dependence on its content in the other fractions, indicating low mobility of iron in vertisols. The strong positive correlation (r = 0.812 and 0.956) between the content of iron in HNO3 and HF and its contents in the primary and secondary minerals (fraction – V) indicate a low content of plant accessible iron in the vertisol. The sequential fractional procedure was confirmed as suitable for accessing the content and availability of iron in the vertisols of Serbia

Original scientific paper Chelate-assisted phytoextraction: effect of EDTA and EDDS on copper uptake by Brassica napus L.

Abstract: Chelate-assisted phytoextraction is proposed as an effective approach for the removal of heavy metals from contaminated soil through the use of high biomass plants. The aim of the present study was to compare the efficiency of the two chelators: EDTA and biodegradable EDDS in enhancing Cu uptake and translocation by Brassica napus L. grown on moderately contaminated soil and treated with increasing concentrations of EDTA or EDDS. Increasing amounts of EDDS caused serious growth suppression of B. napus and an increase in shoot metal concentrations. Growth suppression limited the actual amount of phytoextracted Cu at high concentrations of EDDS. The maximum amount of extracted Cu was achieved by the application of 8.0 and 4.0+4.0 mmol kg-1 EDDS. The shoot Cu concentrations after EDTA application were much lower than with EDDS at the same doses. According to these experiments, EDTA does not appear to be an efficient amendment if Cu phytoextraction with B. napus is considered but EDDS is

Distribution of natural and artificial radionuclides in chernozem soil/crop system from stationary experiments

n The present paper focuses on the determination of radiological characteristics of cultivated chernozem soil and crops from long-term field experiments, taking into account the importance of distribution and transfer of radionuclides in the soil-plant system, especially in agricultural cropland. The investigation was performed on the experimental fields where maize, winter wheat, and rapeseed were cultivated. Analysis of radioactivity included determination of the gross alpha and beta activity as a screening method, as well as the activities of the following radiouclides: natural (Pb-210, U-235, U-238, Ra-226, Th-232, K-40, Be-7) and artificial (Sr-90 and Cs-137). The activities of natural and artificial (Cs-137) radionuclides were determined by gamma spectrometry, while the artificial radionuclide Sr-90 was determined by a radiochemical analytical method. Based on the obtained results for the specific activity of K-40, Cs-137, and Sr-90, accumulation factors for these radionuclides were calculated in order to estimate transfer of radionuclides from soil to crops. The results of performed analyses showed that there is no increase of radioactivity that could endanger the food production through the grown crops