János Tamás

Assessing element distribution and speciation in a stream at abandoned Pb–Zn mining site by combining classical, in-situ DGT and modelling approaches

The distribution and speciation of elements along a stream subjected to neutralised acid mine drainage (NAMD) effluent waters (Mátra Mountain, Hungary; Toka stream) were studied by a multi-methodological approach: dissolved and particulate fractions of elements were determined by HR-ICPMS, whereas speciation was carried out by DGT, supported by speciation modelling performed by Visual MINTEQ. Before the NAMD discharge, the Toka is considered as a pristine stream, with averages of dissolved concentrations of elements lower than world averages. A considerable increase of element concentrations caused by effluent water inflow is followed by a sharp or gradual concentration decrease. A large difference between total and dissolved concentrations was found for Fe, Al, Pb, Cu, Zn and As in effluent water and at the first downstream site, with high correlation factors between elements in particulate fraction, indicating their common behaviour, governed by the formation of ferri(hydr)oxides (co)precipitates. In-situ speciation by the DGT technique revealed that Zn, Cd, Ni, Co, Mn and U were predominantly present as a labile, potentially bioavailable fraction (>90%). The formation of strong complexes with dissolved organic matter (DOM) resulted in a relatively low DGT-labile concentration of Cu (42%), while low DGT-labile concentrations of Fe (5%) and Pb (12%) were presumably caused by their existence in colloidal (particulate) fraction which is not accessible to DGT. Except for Fe and Pb, a very good agreement between DGT-labile concentrations and those predicted by the applied speciation model was obtained, with an average correlation factor of 0.96. This study showed that the in-situ DGT technique in combination with model-predicted speciation and classical analysis of samples could provide a reasonable set of data for the assessment of the water quality status (WQS), as well as for the more general study of overall behaviour of the elements in natural waters subjected to high element loads.

Vegetation Pattern and Heavy Metal Accumulation at a Mine Tailing at Gyöngyösoroszi, Hungary

Abstract Vegetation at an abandoned heavy metal bearing mine tailing may have multifunctional roles such as modification of water balance, erosion control and landscape rehabilitation. Research on the vegetation of mine tailings can provide useful information on tolerance, accumulation and translocation properties of species potentially applicable at moderately contaminated sites. Analyses of the relationship between heavy metal content (Pb, Zn and Cu) and vegetation in a mine tailing were carried out. These analyses included: (1) spatial analysis of relationship among heavy metal distribution, pH and vegetation patterns, and (2) analysis of heavy metal accumulation and translocation in some plant species. Presence of vegetation was found to be significantly dependent on pH value, which confirms that phytotoxicity is a function of element concentration in solution, which is primarily controlled by pH value in mine tailings. Among the most abundant plant species, dewberry (Rubus caesius), vipersbugloss (Echium vulgare), scarlet pimpernel (Anagallis arvensis) and narrowleaf plantain (Plantago lanceolata) accumulate significant amounts of Pb, Cu and Zn, while in the case of annual bluegrass (Poa annua) only Pb can be measured in elevated contents. Considering the translocation features, scarlet pimpernel, narrowleaf plantain, and dewberry accumulate heavy metals primarily in their roots, while heavy metal concentration in vipersbugloss and annual bluegrass is higher in the shoots.

Analysis of a small agricultural watershed using remote sensing techniques

Salinization of land and sweet water is an increasing problem worldwide. In the Carpathian Basin, particularly in arid and semi‐arid regions, irrigation is a contributing factor to the secondary salinization problems, one of the major problems affecting soils in Hungary. Conventional broadband sensors such as SPOT, Landsat MSS, and Landsat ETM+ are not suitable for mapping soil properties, because their bandwidth of 100–200 mm cannot resolve diagnostic spectral features of terrestrial materials. Analytical techniques, developed for analysis of broadband spectral data, are incapable of taking advantage of the full range of information present in hyperspectral remote sensing imagery. In our pilot project in Tedej farm in the Great Plain Region, Hungary, the DAIS sensor was used to assess salinity risk, covering the spectral range from the visible to the thermal infrared wavelengths at 5 m spatial resolution, and other major indicators of soil salinization (NDVI, SAVI, canopy cover) were quantified with advanced remote sensing techniques using the TETRACAM ADC agricultural multispectral camera which offers red/green and NIR imaging at megapixel resolution. As a result, prominent absorption bands around 1450 nm and 1950 nm wavelength in most soil spectra are attributed to water and hydroxyl ions. Occasional weaker absorption bands caused by water also occur at 970, 1200, and 1700 nm. Absorption features near the 400 nm wavelength for all samples are also noticeable. Absorption bands at 1800 and 2300 nm are attributed to gypsum, while strong absorption features near 2350 nm are assigned to calcite (CaCo3). Saline soils exhibited significantly higher reflectance values all throughout the 325–2500 nm wavelengths of the spectrum. Soils with a high amount of soluble salts gave a higher average reflectance than soils with a low salt content. In the project, an ADC camera‐based real‐time integrated system was developed to take advantage of more specialized spectral information and to provide even more accurate and useful data directly from the field. The results revealed that the NDVI and SAVI index and the canopy cover mapping taken with multispectral cameras can be useful as an indirect marker and help for detecting salinization. However, we did not find a strong correlation between NDVI and soil salinity. This is probably because the detection and assessment of lower levels of salinity are difficult, mainly owing to the nature of the remotely sensed images; with such images, it is not possible to obtain information on the third dimension of the 3‐D soil body. Also, the impact of salinity on electromagnetic properties needs to be explored further to understand how it can be derived indirectly from remotely sensed information. With the rapid validation of remotely sensed hyperspectral data, the decision in the future, with the best trade‐off between irrigation and sustainable land use made by agricultural specialists in this region, can be more environmentally sound and more accurate using the results from the pilot.

Biodiversity and Biomass Production of Weeds in a Long-Term Fertilization Experiment

A field experiment was carried out to study the influence of nitrogen (N), phosphorus (P), and potassium (K) nutrient supply on weed flora in maize. The investigations were conducted in a long-term fertilization experiment launched in 2003 on a loamy chernozem soil with lime deposits, in Fejér County, Hungary. The composition, biomass weight, and density of weeds were determined in relation to different nutrient supplies. Seventy-five percent of weeds consisted of three species: Ambrosia artemisiifolia L., Datura stramonium L., and Helianthus annuus L. Density of weeds varied relative to the different nutrient treatments, with a range of 82–131 plants m−2. The total weed density was significantly lower by 19.9–37.8 percent in the N-containing treatments (NP, NPK) than in non-N treatments. The density of the nitrophil D. stramonium L., Chenopodium album L., Chenopodium hybridum L., and Amaranthus blitoides S. Watson was higher when N supply was greater.

Spreading, ecology and damages caused by the common milkweed (Asclepias syriaca L.) in Hungary

One of the biggest challenges for the safe maize production is the yield stability in a wide range of environments with different soil fertility, weather conditions, prevailing pests and diseases as well as cultural practices. In order to achieve it, new hybrids with higher tolerance to biotic and abiotic stress are continuously being created. In order to compare performance of maize hybrids in environments with different levels and types of stress, and relate it to the stalk lodging incidence, we compared performance of 64 maize hybrids obtained by crossing 16 inbred lines with four inbred testers in three different environments. Two environments at same location (Rugvica) differed in crop rotation, and the third environment at location Botinec was considered as dry because of low water capacity of the soil. Mixed models that included all design elements and genetic background of hybrids were used to analyze the effect of lodging on yield in different environments. The results show that stalk lodging had a significant effect on yield, but significant lodging x environment interaction indicates that this effect was rather environment specific.Sweet pepper Istra F1 hybrid was grown in a greenhouse on K rich soil. For evaluation of K antagonism, two K rates (55 and 85 kg ha-1) were applied in a randomized complete block design with four replications. Total number of fruits, total number of BER affected fruits as well as average fruit mass were recorded for each harvest. Fruit and leaf K and Ca content were determined at three plant growth stages (at the stage of the first, third and fifth fruit cluster). Higher K rate gave higher : average fruit mass (169.45 g), total number of fruits per plant (7.95), number of BER affected fruits per plant (3.82), K in leaves (5.44% DM), K in fruits (6.35% DM), but negatively correlated with Ca concentration in fruits (0.57% DM) and leaves (3.24% DM). This resulted in decreased marketable yield of sweet pepper fruits.

Speciation of Heavy Metals in Sewage Sludge

In recent years in Hungary, there has been a growing interest in utilizing soil as a medium for treatment of industrial and municipal wastes. Since sewage sludge has nutrient value, mainly as a source of nitrogen phosphorous and micronutrients, its application to agricultural lands is one way of recycling these nutrients and conserving natural resources. Sewage sludge may contain relatively large amount of heavy metals. To evaluate the ecological risk of this fact we have to measure the element content of soil and sewage sludge. Total metal contents of these samples can be determined easily with ICP spectrometer after digestion with nitric acid. Total amount of heavy metals generally not enough to evaluate the dangers of a these contaminates. The nature of cadmium, chromium, lead, nickel, zinc and copper in biologically and chemically treated sewage sludge was investigate by sequential extraction method. Sequential extraction: The four extracts employed were CaCl2, NaOH, EDTA and nitric acid, as described by McGrath (McGrath 1989) to study the metals in attached to different phases of soil: gave an estimate of: Extraction with 0.1 M calcium chloride gave an estimate of the water soluble and exchangeable fraction of metals; extraction with 0.5 M sodium hydroxide estimated the element organically bound; extraction with sodium-EDTA estimated: oxides and carbonates. After digestion with nitric acid the &

Agricultural biomass monitoring on watersheds based on remotely sensed data.

x2018;residual’ (nitric acid soluble) amounts of elements were determined. 23 elements was determined by inductively coupled plasma emission spectrometer. Samples were taken from the sewage farm of Debrecen (Tamas 1994). Sewage was treated with an adsorbent and was added with calcium-hidroxide. Metal content of liquid aerob sewage sludge and treated, dewatered sludge were studied by sequential extraction. The chemical treating decreased the exchangeable, organically bounded, and carbonate forms of Cd, Cr, Cu, Mn, Ni, Pb and Zn, and increased the residual amounts certainly. This chemical changing was followed under the sewage treating. For example the exchangeable Cd content decreased from 0.202 μg/g to 0.115 μg/g as the result of treatment. The metals concentrated mainly in residual fraction.

Noninvasive Water Stress Assessment Methods in Orchards

There is a close quality relationship between the harmful levels of all three drought indicator groups (meteorological, hydrological and agricultural). However, the numerical scale of the relationships between them is unclear and the conversion of indicators is unsolved. Different areas or an area with different forms of drought cannot be compared. For example, from the evaluation of meteorological drought using the standardized precipitation index (SPI) values of a river basin, it cannot be stated how many tonnes of maize will be lost during a given drought period. A reliable estimated rate of yield loss would be very important information for the planned interventions (i.e. by farmers or river basin management organisations) in terms of time and cost. The aim of our research project was to develop a process which could provide information for estimating relevant drought indexes and drought related yield losses more effectively from remotely sensed spectral data and to determine the congruency of data derived from spectral data and from field measurements. The paper discusses a new calculation method, which provides early information on physical implementation of drought risk levels. The elaborated method provides improvement in setting up a complex drought monitoring system, which could assist hydrologists, meteorologists and farmers to predict and more precisely quantify the yield loss and the role of vegetation in the hydrological cycle. The results also allow the conversion of different-purpose drought indices, such as meteorological, agricultural and hydrological ones, as well as allow more water-saving agricultural land use alternatives to be planned in the river basins.

Evaluation and Controlling of Agricultural Hillside Erosion Based on Integrated GIS Methods

In large orchards up-to-date information is needed on water capacity and possible water stress of the fruit trees because the physiological reactions against the changing water capacity appear much earlier than the water stress. These physiological changes cannot be observed visually in the early period of water stress. One of the most sensitive indicator of photosynthetic activity, mutations, stress the chlorophyll content of the vegetation, which can be monitored by photometry. Thus, combining airborne remote-sensing technology and reflectance measurements of leaves can be the solution for detection of changing water content. With the use of remote-sensing technology, a large amount of agroecologic information can be achieved on sites such as orchards. The examined intensive apple and the extensive pear orchards, established on sandy soils, are situated in the northeastern part in Hungary. The apple orchard has a microirrigation system. Hyperspectral image was taken by AISA Dual airborne hyperspectral camera. The full spectra range of this system is 400–2450 nm, which was set to the maximum 498 spectral channels at the 2.25-m2 spatial resolution. Parallel to the flight campaign, leaf samples were also taken. Samples of different kind of apple species were analyzed by ALTA II and AvaSpec 2048 hand portable spectrometers. Based on the hyperspectral image, vegetation indices were also calculated to detect the effect of water stress. The normalized difference vegetation index (NDVI), which is sensitive to changes in biomass, and the water band index (WBI), which is sensitive to changes in canopy water status, were calculated to measure the water supply of the leaves. As a result, the reflectance of 886 and 937 nm can result more accurate WBI (WBI = δ886/δ937) in the case of pear trees. The water-stressed samples showed a greater reflectance in near-infrared spectrum and a lower reflectance in the red spectrum.

Application of advanced technologies for the detection of pollution migration

The aims of our study were to survey the spatial distribution of physical and water management properties of soils in order to examine erosion risks in orchards and to supply complex research evaluation activities for further studies.