András Makó

Modelling the Potential Effects of the Hungarian Red Mud Disaster on Soil Properties

In this experiment, the effects of the Hungarian red mud disaster were studied in a soil column experiment focusing on element solubility. The effect of flooding with the highly alkaline red mud suspension and the effect of the percolation of precipitation water through the 10 cm thick red mud layer were modelled separately. Both scenarios affected the soil pH up to a depth of 80 cm. An increase in the total element concentration was only observed for Na and Mo, probably due to the leaching of red mud particles measuring 0.05–0.02 and <0.002 mm in the column. At the same time, the water-soluble concentrations of the potentially toxic elements As, Co, Cr, Cu, Ni, Pb, and Zn rose, at least in the top soil layer, but the concentration values remained below the limit values laid down by quality standards. Over a longer period of time, the main environmental risk raised by the disaster is the secondary salinization of the area.

Water Retention of Salt-Affected Soils: Quantitative Estimation Using Soil Survey Information

Soil water retention (SWR) at −0.1, −33, −1500, and −150000 kPa matric potentials and available water content (AWC) were estimated from information available from 729 horizons of salt-affected soils in the Hungarian Detailed Soil Hydrophysical Database. Soil characteristics of the 1:10,000 scale Hungarian soil maps were used as input parameters. Ordinal and nominal (categorical) variables: texture, organic matter content, calcium carbonate content, soluble salt content, pH, and soil subtype classes of the soil map were used to develop a new prediction method based on the CHAID classification tree. Results of the model development were compared with results using conventional prediction methods (classification tree (CRT) and multiple linear regression (MLR)). Four types of pedotransfer rules were established by classification tree methods. The first rule uses continuous-type input parameters, the second uses soil taxonomical information in addition, the third and fourth one uses categorical-type input parameters. In addition, continuous pedotransfer functions (point estimations) were established as well. Results show that the root mean square error (RMSE) of the developed method is between 1.25 vol% (150000 kPa) and 6.40 vol% (−33 kPa). With the mentioned available input parameters, for salt-affected soils the prediction reliability is similar with categorical and continuous-type information. To predict SWR from categorical-type information the CHAID method is advisable. In the case of continuous-type input parameters MLR is suggested, based on this study. The established hydropedologic methods can be readily used to prepare available water content maps for the topsoil of salt affected soils based on solely soil survey information. Supplemental materials are available for this article. Go to the publishers online edition of Arid Land Research and Management to view the free supplemental file.

Effects of leaching from alkaline red mud on soil biota: modelling the conditions after the Hungarian red mud disaster

A soil column experiment was set up to investigate the effect of red mud from Ajka (Hungary) on a typical soil profile from the affected area. The chemical changes caused by the red mud leachate and the effects of these changes on living organisms were assessed. Ecotoxicological tests were performed with Vibrio fischeri, Sinapis alba and Folsomia candida and the number of aerobic heterotrophic microorganisms was determined. The total, plant-available, exchangeable and water-soluble fractions of Na, Mo, Cu and Cr increased in the soil, mostly owing to their leaching from the red mud layer, but partly to the increase in the pH and DOC concentration. The chemical changes only had significant effects on the test organisms in the 0–30 cm soil layer, except for F. candida, which also had a lower survival rate in the 30–50 cm soil layer. No severe toxic effects were detected in the test organisms; in fact a stimulating effect was revealed for the aerobic heterotrophic cell number and for S. alba germination. However, the red mud itself was toxic, so the ecotoxicological tests justified the removal of red mud from the soil surface after the disaster.

Study the estimation possibilities of soil hydraulic conductivity

The most important elements of the soil water regime water retention and hydraulic conductivity are known to play an important role in the fate and transport of organic and inorganic compounds in the soils. They determine the air and water management, biological activity and nutrient management of the soil (Vdrallyay, 2005). The knowledge of the soil hydraulic properties has one of the most important effects on the success of plant production (Baser et al.; 2004, Rajkaine and Szundy, 2004; Farkas et al., 2005). Earlier studies (Mako el al., 2005) proved that soil water retention characteristics can be reliably estimated for soil subtypes using the grouped means of texture and humus content categories of soil maps. In the current work we study predicting possibilities of soil hydraulic conductivity from data of soil maps and cartograms as readily available information. For these studies we used the database of the Hungarian Soil Information and Monitoring System. For estimating of soil hydraulic conductivities we used the TALAJTANonc 1.0 software (Fodor and Rajkai, 2005).

Soil Attribute Parameterization for Plant‐Specific Evaluation of Cropland Productivity in Hungary

Abstract The potential of croplands is determined by annual and seasonal variations in the capacity of the soil to supply water and nutrients. This research was aimed at, with use of the available pedological, topographical, and meteorological data, to describe how yield formation is influenced by the major soil attributes determining fertility and to construct a land evaluation model. The aim was also to describe how fertilization influences the fertility of various soils. For this purpose, data on the soil, agrotechnology, and yield of >80,000 fields, representing approximately 4 million ha of arable land, were statistically analyzed over a 5‐yr period (1985–1989). As part of this work, differences between the most common soil types were evaluated, as manifested in the yield data of wheat. This evaluation was backed up by an analysis of the modifying effects of soil texture, lime status, and nitrogen fertilization. The database of a smaller sample area was used to study the fertility of various soil types for various crops, and calculations were made to quantify the fertilizer effect and the effects of soil characteristics. Results confirm that it is worthwhile performing fertility classification based on soil groupings at higher taxonomic levels. Differences in the fertility of soils with more favorable properties within the soil taxonomic units even out at the highest fertilizer rates, whereas soils with poorer properties, treated with lower rates of fertilizer, exhibit far greater differences in fertility. The best way to achieve a complex quantification of the effect of attributes which influence productivity seems to be by differentiating between soil types, taking into consideration the major physical and chemical characteristics of the particular soil units.

Role of soil properties in water retention characteristics of main Hungarian soil types

Relationship between easily available soil properties and soil water retention at given matric potentials were analysed on brown forest soils, chernozems and meadow soils of Hungarian Detailed Soil Hydrophysical Database (Hungarian acronym: MARTHA). We studied the influence of soil properties displayed on the 1:10000 scale Hungarian soil maps on soil water retention at -0.1, -33, -1500 and -150000 kPa. Continuous (particle size distribution, organic matter content, calcium carbonate content and pH) and category type (ordinal: soil texture, ordinal type information on organic matter content, calcium carbonate content and pH; nominal: soil subtype classes) variables were used in the analyses. The relationships was analysed with random forest method based on conditional inference trees (cforest). Water retention of different soil types was characterized. Importance of soil properties in the prediction of soil water content varies according to soil type and matric potentials.

Comparison of Nonaqueous Phase Liquids' Conductivity and Air Permeability of Different Soils

It was recently shown that estimated transport parameters for nonaqueous phase liquids (NAPLs) could differ significantly from measured parameters because of poor estimates for fluid conductivity. Most of the estimation procedures of the different multiphase flow simulators assume that porous media are rigid and noninteracting (ideal porous medium). This assumption is not valid in aggregated soil systems consisting in part of clay minerals. Inadequate conductivity estimates may be a direct result of desaggregation or clay volume changes (pore‐size distribution changes) when contact with different fluids occurs. To expand the experimental data set of models describing the movement of organic liquids polluting the soils and possibly to discover new relationships between the NAPL conductivity and the other soil parameters, a series of experiments was set up in which the air permeability was measured with a PL 300 permeameter (UGT) and the fluid (NAPL and water) conductivity was measured using the falling head method. The measurements were carried out on artificial soil columns. The soils originated from different horizons of characteristic Hungarian soils. The relationships between the NAPL conductivity and the various other soil parameters were examined statistically. To give a better prediction for the NAPL conductivity, a new estimation method that is based on the easily measurable soil parameters was suggested.

Soil fertility assessment in a case study in Hungary

Introduction The wild plants accommodate to the soil conditions themselves but the plants which are produced by us are grown on different soil types and soil conditions. So it is important to know which soil type can grow arable crops with the best success. (Fekete, 1958) The specific land use allows that the plant production should be profitable in the way of sustainability of fertility on croplands. (Birkas, 2001) Soils have been described for many years in terms of the proportions of particles of different sizes that they contain. This basis of characterization soils developed because particle size is an obvious characteristic related to soil behavior and plant response. (Black, 1967) The main goal of this study was to evaluate crop lands on an objective basis and to create land use classes with the help of the evaluated values. Land evaluation helps the correct planning of agronomic land use very much. This study introduces how you can evaluate the soil fertility through the potential agronomic production. The method determines the production potential of agricultural lands in a quantitative way.

Nonaqueous-Phase Liquid Retention of Mineral Mixture Series Containing Different Clay Minerals

The pollution of soils with nonaqueous-phase liquids (NAPL) may endanger the quality of soils, their utilization, and the groundwater reservoir. To develop NAPL transport models, the most important soil parameters are the hydrophysical properties of the solid phase such as the retention capacity. Because the measurement of these soil properties is time-consuming and costly, in most cases they are estimated. However, the commonly used estimation methods are mostly validated with laboratory measurements using soil columns made from sand, quartz, or glass-bead samples, with negligible contents of clay and organic matter. These estimation methods consider the soil as ideal porous media and thus may not provide appropriate results for soils with variably physical and chemical properties. In the 1990s a research program commenced at this university to create an appropriate estimation method for predicting the NAPL retention capacity of soils. Two estimation methods, the Leverett equation and the prediction with pedotransfer functions (PTF), were compared. We assumed that the oil retention of soil is sufficiently predictable from basic soil properties, but we later discovered that these models needed to be refined further because NAPL retention in soils may be influenced by different properties at a higher pressure level than at lower pressure. Moreover, the quantity and the quality of clay minerals in soils may also influence the retention capacity of soils. The aim of this study was to determine the effect of different investigated soil parameters on NAPL retention measured at different pressure values. A series of mineral mixtures containing different clay minerals were used, the PTFs were established, and the role of the main soil properties in NAPL retention was investigated with statistical analysis.

Climate sensitivity of soil water regime of different Hungarian Chernozem soil subtypes

In this study the possible effects of two predicted climate change scenarios on soil water regime of Hungarian Calcic Chernozem soils has been investigated. Soil profiles classified as Calcic Chernozem — in total 49 — were selected from the MARTHA soil physical database that incorporates soil data at national scale. These profiles were subdivided into three groups (sandy loam, loam and clayey loam) in accordance with their mechanical composition. Soil water retention curves were scaled separately for each of the three textural groups, using similar media scaling in order to represent the variability of soil hydrophysical data with one parameter, the scaling factor (SF). Reference soil profiles were chosen according to the cumulative distribution function of the scaling factor, six for each textural group. Daily downscaled meteorological data from A2 and B2 climate scenarios of the Hadley Centre (2070–2100) and data from a reference period (RF, 1961–1990) were used in this study to characterize different climatic situations. Nine representative years were selected in case of all the three scenarios, using the cumulative probability function of the annual precipitation sum. Scenario analyses were performed, validating the SWAP soil water balance simulation model for the 18 reference soil profiles and 27 representative years in order to evaluate the expected changes in soil water regime under different from the present (RF) climatic conditions (A2 and B2 scenarios). Our results show that the scaling factor could be used as a climate sensitivity indicator of soil water regime. The large climate sensitivity of the majority of Chernozem soil subtypes water regime has been proven.