EURASIAN JOURNAL OF SOIL SCIENCE

153 - 160

Authors: Maria Manuela Carvalho, Maria Cristina Vila, Cristina Delerue-Matos, Maria Teresa Oliva-Teles, António Fiúza

Bioremediation is an attractive and useful method of remediation of soils contaminated with petroleum hydrocarbons because it is simple to maintain, applicable in large areas, is economic and enables an effective destruction of the contaminant. Usually, the autochthone microorganisms have no ability to degrade these compounds, and otherwise, the contaminated sites have inappropriate environmental conditions for microorganism’s development. These problems can be overcome by assisted bioremediation (bioaugmentation and/or biostimulation). In this study the assisted bioremediation capacity on the rehabilitation of three natural sub-soils (granite, limestone and schist) contaminated with benzene was evaluated. Two different types of assisted bioremediation were used: without and with ventilation (bioventing). The bioaugmentation was held by inoculating the soil with a consortium of microorganisms collected from the protection area of crude oil storage tanks in a refinery. In unventilated trials, biostimulation was accomplished by the addition of a nutrient mineral media, while in bioventing oxygen was also added. The tests were carried out at controlled temperature of 25 ºC in stainless steel columns where the moist soil contaminated with benzene (200 mg per kg of soil) occupied about 40% of the column’s volume. The processes were daily monitored in discontinued mode. Benzene concentration in the gas phase was quantified by gas chromatography (GC-FID), oxygen and carbon dioxide concentrations were monitored by respirometry. The results revealed that the three contaminated soils were remediated using both technologies, nevertheless, the bioventing showed faster rates. With this work it was proved that respirometric analysis is an appropriate instrument for monitoring the biological activity.

169 - 177

Authors: Martin Reiss, Peter Chifflard

Periglacial cover beds are an important trigger of slope-water paths in sloped terrain of the mid-latitudes. Most hydropedological studies focus on the quantitative analysis about the interrelation between subsurface layering and runoff processes at the slope scale. In this research we emphasis on a qualitative environmental geochemical analysis of trace elements and dissolved organic carbon in a small forest hydrological study area in the central parts of the subdued mountains of Germany (Location: KrofdorferForst, +50° 41' 3.69", +8° 38' 38.87"). The main objective is to assess the effect of lithological discontinuities of stratified soils within the depth functions of trace elements concentration in soil solutions (soil water and its dissolved and mobile fraction in a vertical distribution). Lorz (2008) show that depth functions of manganese (Mn) are characterized by strong pedogenic dynamics, analysing a shortened sequential extraction of solid soil material. We investigated the hypothesis that lithological discontinuities act like aquicludes. Therefore we expect abrupt changes within the depth function of manganese as a result of such water-blocking effect (= geochemical barriers) as a consequence of mobilization under wet soil conditions. In a preliminary case study we sampled soil solutions from three different plots within a 400m-toposequence. We use in situ trench installed suction lysimeters with ceramic tips (Irrometer Soil Solution Access Tube) to extract soil water samples each 20 cm from top- (10 cm) to subsoil (110 cm). For geochemical element analysis we use an inductively coupled plasma mass spectrometry (ICP-MS). The results: A clear character of abrupt changes within the depth function could be illustrated for most of the plots. For example, at the upper slope plot a contrast of the depth function is from 1013 ppb mean concentration at 50 cm profile depth to 290 ppb mean concentration at 70 cm profile depth (17 month sampling period). To conclude, these results demonstrate that hydrochemical quality and translocation processes of soil solutions determining an interrelation between subsurface layering and run off processes - respectively could be seen as an environmental consequence of it.

185 - 190

Authors: Zeynep Demir, Coşkun Gülser

Effects of rice husk compost (RHC) on some soil quality parameters under greenhouse conditions were investigated. Experiment were conducted in a randomized plot design with different application doses of RHC (0, 3, 6 and 9%) into surface soil (0-20 cm) with three replications in a greenhouse of Agricultural Faculty in Ondokuz Mayıs University. RHC application generally improved the soil quality parameters according to the control treatment during the experiment carried out with growing tomato plant in the greenhouse in 2010. The soil organic matter (OM) contents significantly increased by the application of RHC in the following order; 9%>6%>3%>0%. While RHC applications in the greenhouses significantly reduced pH contents of soils according to the control, the RHC application increased the values of respiration rate (CO2), EC, NO3-N and available phosphorus (P). While the exchangeable Ca values of soils generally decreased, the exchangeable Mg and K values generally increased according to the control with RHC application. Bulk density (BD) values in the greenhouse were reduced with RHC application doses in the following order 0%>3%> 6%>9%. The values of field capacity (FC), permanent wilting point (PWP) and available water capacity (AWC) generally increased according to the control with the application of RHC dosses in the following order 9%>6%>3%. The highest positive correlations among the physical, chemical and biological properties were found between OM and PWP (0.924**), AWC and FC (0.907**), OM and FC (0.897**), CO2 and PWP (0.862**), PWP and FC (0.791**); while the highest negative correlations were found between BD and FC (-0.854**), BD and PWP (-0.871**), BD and OM (-0.868**), BD and CO2 (-0.838**), BD and P (-0.821**), Ca and FC (-0.812**). The highest tomato yield (7.77 ton/da) was obtained with the 9% of RHC application. RHC application to the soil in greenhouse generally improved soil quality and tomato yield.

198 - 202

Authors: Dolgor Khaydapova, Evgeny Milanovskiy, Evgeny Shein

Rheological properties of kaolinite, montmorillonite, ferralitic soil of the humid subtropics (Norfolk island, southwest of Oceania), alluvial clay soil of arid subtropics (Konyaprovince, Turkey) and carbonate loess loam of Russian forest-steppe zone were determined. A parallel plate rheometer MCR-302 (Anton Paar, Austria) was used in order to conduct amplitude sweep test. Rheological properties allow to assess quantitatively structural bonds and estimate structural resistance to a mechanical impact. Measurements were carried out on samples previously pounded and capillary humidified during 24 hours. In the amplitude sweep method an analyzed sample was placed between two plates. The upper plate makes oscillating motions with gradually extending amplitude. Software of the device allows to receive several rheological parameters such as elastic modulus (G’, Pa), viscosity modulus (G", Pa), linear viscoelasticity range (G’>>G”), and point of destruction of structure at which the elastic modulus becomes equal to the viscosity modulus (G’=G”- crossover). It was found out that in the elastic behavior at G '>> G " strength of structural links of kaolinite, alluvial clay soil and loess loam constituted one order of 105 Pa. Montmorillonit had a minimum strength - 104 Pa and ferrallitic soil of Norfolk island [has] - a maximum one -106 Pa. At the same time montmorillonite and ferralitic soil were characterized by the greatest plasticity. Destruction of their structure (G '= G") took place only in the cases when strain was reaching 11-12%. Destraction of the kaolinite structure happened at 5% of deformation and of the alluvial clay soil and loess loam - at 4.5%.

211 - 219

Authors: Joulia Meshalkina, Alexis Yaroslavtsev, Ilya Mazirov, Miljan Samardzic, Riccardo Valentini, Ivan Vasenev

The eddy covariance (EC) technique as a powerful statistics-based method of measurement and calculation the vertical turbulent fluxes of greenhouses gases within atmospheric boundary layers provides the continuous, long-term flux information integrated at the ecosystem scale. An attractive way to compare the agricultural practices influences on GHG fluxes is to divide a crop area into subplots managed in different ways. The research has been carried out in the Precision Farming Experimental Field of the Russian Timiryazev State Agricultural University (RTSAU, Moscow) in 2013 under the support of RF Government grant # 11.G34.31.0079, EU grant # 603542 LUС4С (7FP) and RF Ministry of education and science grant # 14-120-14-4266-ScSh. Arable Umbric Albeluvisols have around 1% of SOC, 5.4 pH (KCl) and NPK medium-enhanced contents in sandy loam topsoil. The CO2 flux seasonal monitoring has been done by two eddy covariance stations located at the distance of 108 m. The LI-COR instrumental equipment was the same for the both stations. The stations differ only by current crop version: barley or vetch and oats. At both sites, diurnal patterns of NEE among different months were very similar in shape but varied slightly in amplitude. NEE values were about zero during spring time. CO2 fluxes have been intensified after crop emerging from values of 3 to 7 µmol/s∙m2 for emission, and from 5 to 20 µmol/s∙m2 for sink. Stabilization of the fluxes has come at achieving plants height of 10-12 cm. Average NEE was negative only in June and July. Maximum uptake was observed in June with average values about 8 µmol CO2 m−2 s−1. Although different kind of crops were planted on the fields A and B, GPP dynamics was quite similar for both sites: after reaching the peak values at the mid of June, GPP decreased from 4 to 0.5 g C CO2 m-2 d-1 at the end of July. The difference in crops harvesting time that was equal two weeks did not significantly influence the daily GPP patterns. Cumulative assimilation of CO2 at the end of the growing season was about 150 g C m−2 for both sites. So the difference in NEE was the consequence of essentially higher respiration rates in case of vetch and oats (about 350 g C m−2) comparing to barley (250 g C m−2) that needs additional research. The results have shown high daily and seasonal dynamic of CO2 emission too as a result of different and contrasted conditions: crop type, crop development stage, soil moisture and air temperature. Obtained unique for Russian agriculture data are useful for land-use practices environmental assessment, for soil organic carbon dynamics analysis and agroecological evaluation.