Jonas Volungevičius

The role of pH in heavy metal contamination of urban soil

AbstractThe aim of this study to assess interdependence between urban soil pH and its accumulation of heavy metals. The article meant to be a contribution to a better knowledge of peculiarities and diagnostics of urban soil and its anthropogenic transformation. The hypothesis assumes that relationship between urban soil pH and its accumulation of heavy metals may be determined by the origin and age of parent material as well as the nature and degree of the anthropogenic impact. The spatial variability of topsoil pH level was performed in 100 points in eldership of Snipiskės of the city Vilnius. Laboratory analysis was based on ISO 10390:2005. Samples were collected from 20 cm topsoil layer in the same sampling points where have been analysed concentrations of topsoil chemical elements using optical atomic emission spectrophotometry. The contamination of urban soils exhibits somewhat different compared to agricultural soils. In contradiction to earlier studies in Lithuanian agricultural soils where strong ...

The problem of soil interpretation according to the WRB 2014 classification system in the context of anthropogenic transformations

ABSTRACT Evaluation of soil transformations and degradation is important not only for agriculture, but also for fundamental research on identification of new features for classification. In 1999, new Lithuanian soil classification (LTDK-99) was developed by adopting the diagnostic principles of WRB 1998. Together with new knowledge, it highlighted some relevant soil research and classification problems. Not only new terms but also diagnostic features of several newly distinguished first-level soils groups are being discussed, especially for the identification of cambisols, planosols, arenosols, and regosols. Additionally, a group of stagnosols is suggested for inclusion into this classification. The presence of glaciogenic secondary clay minerals in Lithuanian cambisols does not imply unambiguous brownification involvement, neither any study shows cambisols having specific to brownification iron minerals. The intensively occurring lesive in these soils questions correctness of identification of cambisols additionally aggravated by strong and deep anthropogenization of the soil profiles within the territorial range. Complex glaciogenesis makes it difficult to identify Lithuanian planosols. WRB 2014 (update 2015) identifies planosols according to the pedogenesis in old, strongly weathered binomial deposits using examples mostly from South American, South and East African plateaus of the subtropical zone. The same classification assigns planosols identified in Lithuania to stagnosols, that is, to the soils characterized by binomial genesis and stagnification. The diagnostic features of arenosols and regosols are similar in both groups and are related to primitive pedogenesis. Difficulties in distinguishing between the two groups in Lithuania are strengthened by the intensive cultivation of the ecosystems in their territorial range. The existing problems in Lithuanian soil diagnostics underline the questions of soil classification in general, especially regarding the evolution tendencies in soil classification. The article draws attention to the soil diagnostic aspects like distribution and genesis of clay particles, genesis of territory, and anthropogenic transformation for the improvement of soil identification.

The effects of agrogenic transformation on soil profile morphology, organic carbon and physico-chemical properties in Retisols of Western Lithuania

ABSTRACT The aim of this study was to determine changes in the morphological, physical and chemical properties of Retisols caused by their agrogenic transformation. The study carried out on Retisols on relatively natural and agrogenically affected land in 2016. Soil samples taken from the genetic horizons of all profiles to measure soil organic carbon, pH, hydromorphic and physical properties. Due to long-term, deep ploughing, the sequence of soil horizons in the Retisol profile had changed from O–Ah–El–ElBt to Ahp–ElBt. Intensive soil liming changed chemical properties and morphological features of Retisol. The clay and silt particles leached out of from the Ah and El horizons to the deeper layers due to illuviation and podsolization. The content of SOC in the 0–30 cm layer of the Ah horizon of agrogenically affected Retisol was 1.0%, and in the forest Retisol – 1.7%; however, forest Retisol was more acidic. Ploughing and no tillage management caused a reduction in total porosity, water holding capacity and plant available water content compared with the other land-uses. We conclude that the use of ploughless tillage on Retisol is not identical to the conditions of natural soil formation and soil fertility maintenance.