Sorina Dumitru | University of Bucharest (original) (raw)

Papers by Sorina Dumitru

The objective of this paper is to present a sketch map of the accumulation of soluble salts in so... more The objective of this paper is to present a sketch map of the accumulation of soluble salts in soils from Romania, as a support for improving saline soils or preventing undesirable anthropogenic salinization phenomena. The map highlights the spatial distribution and movement of easily soluble salts in soil at the scale of the entire country, It is an overview on origin, sources and pathways of migration and accumulation of easily soluble salts in interdependence with natural factors and conditions. Taking into account the movement pathways of easily soluble salts in soil, two geochemical zones were separated on the map: the eluviation-transit zone and the transit-accumulation zone. In the last zone, areas where the accumulation of salts becomes dominant have been delimited, their transit being insignificant. The movement directions of easily soluble salts in soil are also highlighted on the map. From a naturalistic point of view, the map highlights the close connection between areas with accumulation of salts and areas where geological, geomorphological and hydrogeological conditions lead to a poor drainage. It also highlights the connection and importance of salt sources from geological deposits or salt masses in the hilly area in the formation, expansion and chemistry of saline soils in the plain or floodplain areas located in the neighbouring lowlands.

Carpathian Journal of Earth and Environmental Sciences, Jan 25, 2023

Active C, as a measure of the level of chemical oxidation of organic matter, reflects the carbon ... more Active C, as a measure of the level of chemical oxidation of organic matter, reflects the carbon available to microorganisms. Soil respiration, as a direct way to estimate edaphic microbial activity, could be a measure of the fluctuations of carbon stocks in soils. To determine the ability of soil respiration to evaluate such fluctuations we used soils with an increased content of organic carbon, constant optimal conditions, to eliminate the disturbing factors, analyzed in a short period of time. The influence of the specific decomposition rates of these soils was assessed by both spot determinations of soil respiration and analyzing the flux of CO2 from ex situ soil samples, under standard experimental conditions, to highlight carbon storage in such soils. Reference data can be accumulated through the analysis of these parameters, which compared with the results of quantitative/qualitative determinations regarding the changes in the content of microbial biomass, the content of fulvic sub-fractions, the fluorescence of dissolved organic material and the evolution of the content of siderophores, could be considered, by their own evolutions, as arguments in sustaining the use of respiration in the efficient estimation of carbon storage evolution in the soils. The analyses of these parameters were carried out in two phases, for comparing initial and final data of experiment (after 30 days). The soils had different levels of the respiration potential between phases. The level of soil respiration was reduced in time between 4.27-14.60%, in each soil. The CO2 flux showed, in time, a continuous decreasing trend in both soils. In the case of Mollic Histic Gleysol (Salinic), the coefficient of determination has the value R2=0.92 for the flux determined in the final phase. The levels of microbial biomass of both soils were increased significantly at the end of the experiment. In the case of Mollic Histic Gleysol (Salinic), microbial biomass increased from 456±23.12 μgC∙g-1 to 514±24.57 μgC∙g-1 soil. The fulvic sub-fractions A-D of both soils revealed significant accumulates of soluble organic compounds, with different molecular weights and complexity levels, after 30 days of incubations in standard conditions. The fluorescent components present in the water-extractable organic matter were highlighted by imagistic method. The highest degree of storages of newly bio-synthesized compounds of carbon was registered in organic matter of Mollic Histic Gleysol (Salinic). The intensity of siderophores biosynthesis increased over time, starting from an initial lower presence in the Mollic Gleysol (Salinic) (with Ø 11 mm halo), which were followed by an increasing of siderophores content and availability of iron, at the end of the experimental period. Accumulations of siderophores in the Mollic Histic Gleysol (Salinic) determined a Ø 31 mm halo diameter.

Research Journal of Agricultural Science, 2009

Natural soil bodies are the result of climate and living organisms acting on parent material with... more Natural soil bodies are the result of climate and living organisms acting on parent material with topography or local relief exerting a modifying influence and with time required for soil forming processes to act. One of the main characteristic of the soils is their ability to support growing of living plant out-of-door. Therefore, a good knowledge of soil resources is a prerequisite condition for any good management of agricultural lands. This paper refers to an important part of the Romanian Lower Danube Plain, known as the Braila Plain or Northern Baragan. Its main goal is that to emphasize the geographical distribution of soils according to different geomorphological subunits and pedogeoclimatic microzones. For describing the studied area the Geografic Information System of the Pedogeoclimatic Microzones (GIS-MZP) was used, each microzone being characterized according to specific climate, relief and dominant soil conditions. This operation involved overlapping of soil map with that of microzones one. The use of soil cover data improved the information comprised by former microzones. So, the material elaborated earlier has been revised and up dated with new pedological and climatic information. The main limiting factor for agricultural use of soils from Braila Plain results from the persistent climatic moisture deficit that affects the whole area. Locally, risks of soil salinisation as well as wind erosion also occur. The results of this research, unequivocally underline the necessity of adequate measures for a better soil management, as well as for an improved soil and environment protection.

Carpathian Journal of Earth and Environmental Sciences, Feb 1, 2022

Pollution can occur in any environment, but the way the pollutants spread over depends on the env... more Pollution can occur in any environment, but the way the pollutants spread over depends on the environmental features. Some pollutants remain more or less confined to the contamination site, others do not. This paper proposes a territory zoning showing lands susceptibility for possible groundwater pollution through leaching in Romania, if pollution occurs. The method uses a GIS technique and takes into account soil permeability and texture, relief type, depth to groundwater and climatic water deficit. Six land susceptibility classes were obtained for the whole territory. The highest vulnerability to groundwater pollution was assessed for the most permeable sandy soils, or near - river soils, whereas the most resilient environment was assessed for the low permeable clayey soils. This land classification is aimed at drawing attention to stakeholders in order to rank and take the most appropriate measures to prevent and control pollution, if occurring. The regions that are most vulnerable to pollution should be managed with more care than the most resilient regions. If global warming continues, more severe rainfall events are expected to happen, thus enhancing the leaching of pollutants toward groundwater, specifically for the most vulnerable classes.

Annals of the University of Craiova - Agriculture, Montanology, Cadastre Series, Jan 4, 2023

The current status of Great Brăila Island is the result of an extensive activity of damming/drain... more The current status of Great Brăila Island is the result of an extensive activity of damming/draining/land reclamation of the Brăila Swamp with the aim to be used in agriculture. The final areas obtained from this complex activity preserve the specific variability of the flood areas. In order to be used in agricultural purposes, they need crop technologies which capitalize the physical and chemical soil properties. In order to highlight this variability, physical and chemical analysis on soil samples have been done. The analyzes highlighted the following: the soil texture is uniform (clayey and clay-loamy); the indicators characterizing the structural soil state indicate a good structural aggregation; soil reaction is weakly alkaline on the profile for the entire area; humus content varies from low to medium; the total nitrogen content varies from low to high (the vast majority of samples having medium contents); available phosphorus content varies from high to very high; available potassium content ranges from medium to very high; the total content of soluble salts indicates non-saline soils, while the total cation exchange capacity has medium and high values. The statistical analysis of the studied indicators indicates a coefficient of variation with values between 1.99% for the soil reaction and 53.17% for the structural instability index. Detailed analysis of these coefficients indicate a higher variability for the easily exchangeable indicators (such as nutrient supply) and a lower variability for stable elements (total cation exchange capacity, soil texture and soil reaction, being dependent on parent material). The results of the study highlights a relative homogeneity of the area, the indicators varying inside the same class of values, allowing the application of homogenous agricultural technologies on the study area.

Carpathian Journal of Earth and Environmental Sciences, Aug 31, 2022

Soil organic carbon (SOC) sequestration generally occurs in wet ecosystems such as river flood pl... more Soil organic carbon (SOC) sequestration generally occurs in wet ecosystems such as river flood plains and deltas. This paper deals with the carbon sequestration stock in the Danube Delta soils for various depths as based on the existing soil maps and updated materials and discusses about greenhouse gas emissions in order to enable evaluation of future evolution and possible scenarios in the light of global warming. Histosols represent about 28% of the Delta area and contribute with over 55% to the total SOC pool of this ecosystem. The histic subtypes of the Subaquatic Fluvisols, Gleysols and Arenosols also contribute much more to the total SOC pool than the non-histic subtypes. The large and significant SOC differences between mineral and organic soils is a strong reason for preservation of Histosolsʼ area and for renaturation of some less fertile soils from the lowest parts of Danube Delta in order to increase SOC and decrease atmospheric C. Only about 14.5% from the total Danube Delta area was taken for farming, mainly in its western part, where mineral soils or subtypes of organic soils occur. Histosols are especially situated in the maritime, eastern parts of the Delta ecosystem. In cropland areas the soil depth that is mobilized by plowing, disking or other works and from where the plants uptake water and nutrients is at least 0.5 m, and for some crops even from 1.0 m or below. The present paper deals with various soil depths for SOC referenced values, facilitating their use in specific estimation models. Policy makers, decision makers and opinion-formers should promote preservation of the natural landscape of the Delta under the best possible conditions to contribute to an increase in SOC stock. Maintaining the natural SOC stock at the present-day level and enhancing new organic C deposition in the renatured parts of Delta soils could contribute to global warming mitigation in the future. If global warming continues at the present rate or higher rates, the soil water regime will change reflecting the dynamics of sea level rising. This event will most probably accelerate peat formation and increase Histosol area in the lowest landforms across the Delta. Future research is needed for characteristic stationary sites specifically in the cropland area of the Danube Delta to deepen our knowledge regarding the dynamics of SOC.

Carpathian Journal of Earth and Environmental Sciences, Jan 25, 2023

Soil organic carbon (SOC) is an important parameter in the context of global warming, and a speci... more Soil organic carbon (SOC) is an important parameter in the context of global warming, and a special attention should be given to its dynamics. The purpose of this paper is to test the existence of SOC losses from the soils taken for farming for more than 25 years in some areas of the Danube Delta. Another objective is to quantify such SOC losses if they exist. The studied soils belong to two land reclamation areas, Carasuhat and Dunavat, from the Danube Delta. Data of present-day SOC stocks were compared to the SOC stocks calculated for the period until year 1996 for the same soil units in order to assess the dynamics of SOC losses for more than 25 years. We have found that a specific process was noted for the organic soils, Histosols, which were turned into histic soils after farming, meaning that there was a significant decrease in SOC pool. Thus, SOC losses due to farming were maximum for Histosols, and SOC stocks were highly significantly lower in 2022 versus 1996, due to increasing mineralization processes of organic matter and subsequent greenhouse gas emissions that occurred in cropland areas. Relationships have been found quantifying SOC losses versus the original 1996 stocks, confirming that Histosols, containing the maximum SOC stocks, present the highest risk of degradation. Lowering of the ground water and consequently the intensified oxidation of peat are very important factors in SOC losses beside the agricultural land use works. Policy makers, decision makers and stake holders should promote conservation of the natural landscape of the Danube Delta in order to increase SOC stocks and decrease CO2 and other greenhouse gas emissions into the atmosphere. Maintaining the former SOC stock at the present-day level and enhancing new organic C sequestration in the renatured parts of the less fertile Delta soils could contribute to global warming mitigation in the future and to supply agricultural products in the cropland already in use. Future research in characteristic stationary sites of the Danube Delta, especially in the farmland area, is recommended to improve our knowledge on SOC evolution.

"Annals of the University of Craiova - Agriculture Montanology Cadastre Series "

The sandy soils are sensitive ecosystems, being in a precarious equilibrium with the pedolandscap... more The sandy soils are sensitive ecosystems, being in a precarious equilibrium with the pedolandscape conditions, any changes could bring drastically modifications into the soil environment. The researches had been performed in Suceava Tableland, in Stephan the Great area, on a Luvosol albic-psamic, lamelar. The researches in the paper focused on the upper part of the argic horizon, on Bt1 sub-horizon characteristics at macro- and microscopic scale. In this respect, at the macro-morphological level, the Bt1 sub-horizon is composed of a sequence of thick lamellae (3–5 cm) separated by the inter-lamellar spaces. The granulometric analysis showed that the lamellae had a medium loamy texture, while the inter-lamellar spaces had coarse granulometric composition. At micromorphological level, the image emphasized, in the lamellae, the presence of the clayey±Fe±humiccoating the mineral grains and clogging part of the inter-granular spaces. The results of the microbiological investigation showe...

Journal of Environmental Protection and Ecology, 2016

SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings, 2011

Activity of non-ferrous metallurgical plant from Zlatna were released directly to atmosphere high... more Activity of non-ferrous metallurgical plant from Zlatna were released directly to atmosphere high levels of heavy metal, most of them were deposited on soil. The soil acts as a sink in which heavy metals are accumulated. The object of this study is to assess the distribution of copper along the different soil profile at specific distance from the pollution sources and under different land use. The vertical distribution of total copper was studied on 25 soil profiles. The main soils from investigated area are: Dystric Cambisols, Eutric Cambisols, Haplic Luvisols, Luvisols, Regosols, Fluvisols, and strongly eroded soils. The studied soils have been classified according to their main characteristics in agreement with WRB 98. The soil samples were taken from each soil horizons. The field studies were made on area of the influence of Ampellum Zlatna S.A, on 14 km upstream and 22 km downstream of contaminating source The total copper was measured with flame atomic absorption by a mixture of strong acids (hydrochloric, sulphuric and perchloric acid-5:10:1 ratio). In the examined soils, generally, the copper soil profile distribution show a maximum value in the top soil and then decrease with depth. Between soils copper content and soil organic matter of studied soil was established a very significant correlation. The highest values of total copper were determined in the litter, followed by pasture and arable land. In soil used as forest, the cooper is highly accumulated in the forest litter and then decrease on soil profile. The highest contents of total copper in soils used as meadow are retained in the top few centimeters of the surface soil. In case of arable land use, the maximum values are recorded under plowed layer and then decrease on soil profile. The distribution of the copper on soil profile presented less variation with soil type, but rather with distance from pollution source and land use. The human impact of metal accumulation in top soil was confirmed by the fact that concentrations of copper decreased with depth.

AgroLife Scientific Journal, Jun 30, 2023

The rational and efficient management of land resources, in the frame of a sustainable agricultur... more The rational and efficient management of land resources, in the frame of a sustainable agriculture and environment protection, have to be based on the operational, and at the same time, more detailed and accurate knowledge of soil resources. This knowledge is based on soil information obtained by carrying out soil surveys and field research, and by laboratory measurements of main soil physical and chemical parameters. Thus, the basic soil information, consisting primarily of data on soil profiles representative of the study areas is obtained. The objective of this paper is to develop several applications for coupling georeferenced data from Geographic Information System of Soil Resources SIGSTAR-200 with the information of soil profiles from the Soil Quality Monitoring Network 8 km x 8 km. The spatial distribution of existing soil profiles, as well as the distribution of soil types have been studied, and their representativeness is determined. IT applications have been developed to highlight the number of profiles consistent with the polygons containing them, or with the neighbouring polygons. The soil areas that are described by a profile from the soil profiles database (having a profile which is located inside the polygon) are also established.

15th International Multidisciplinary Scientific GeoConference SGEM2015, INFORMATICS, GEOINFORMATICS AND REMOTE SENSING, 2011

Journal of Environmental Protection and Ecology, 2013

Research Journal of Agricultural Science, 2011

The main purpose of the study presented in this paper was to assess the influence of amelioration... more The main purpose of the study presented in this paper was to assess the influence of amelioration measures on the soil microbial communities and their physiological activities in experimental field from Maxineni-Corbu Nou. Since in literature there are few data and information on the relationships between the amelioration processes and soil microbiological activity in saline soils, researches aiming to highlight the changes that occur, both in their activity and qualitative and quantitative distribution of microorganisms in relation to soil desalination were developed. The concept of intensive amelioration of saline soils includes both the application of a set of agropedoameliorative measures based on drainage and irrigation, adapted to specific conditions and restoration of biological activity. To highlight the main aspects of microbiological activity in saline soils, measurements in the experimental field Maxineni- Corbu Nou from Braila county were done. This field was established...

Research Journal of Agricultural Science, 2010

This study tackles an interdisciplinary water resources issue, comprising one of the joint resear... more This study tackles an interdisciplinary water resources issue, comprising one of the joint researches in Meteorology, Hydrology, Soil Science and Agronomy. Thereby, the main hydrometeorological parameters for identifying areas affected by water deficit will be discussed. Drought is one of the major natural hazards that may cause great losses to the rural community each year, due to the dependence of agriculture on water resources, especially water scarcity. In the investigated area (Bend Subcarpathians and peripheral zones), a greater frequency of dry autumn seasons characterizes especially northern part, starting from Buzău. A higher frequency has been identified along the Prahova Valley, too. In some areas, the mean maximum ranges of the consecutive dry days exceed annually 30. A larger interval for average number of days with no rainfall is registered in autumn (more than 22 days in nearly the whole Subcarpathians area). An analysis of frequency of annual minimum monthly mean dis...

Annals of the …, 2010

... MOCANU VICTORIA, DUMITRU SORINA, COTEŢ VALENTINA, EFTENE MARIUS MOCANU VASILE ... Agr. Bucure... more ... MOCANU VICTORIA, DUMITRU SORINA, COTEŢ VALENTINA, EFTENE MARIUS MOCANU VASILE ... Agr. Bucureşti, 191; 349; 226 p. 3. *** 2003 - Sistemul Român de Taxonomie a Solurilor (SRTS), Florea N., Munteanu I., Editura Estfalia, Bucureşti, 182 p. Formatted: Justified

soilscience.uaic.ro

At European level, people and policy makers start to feel very strongly about environment issues.... more At European level, people and policy makers start to feel very strongly about environment issues. The agricultural activities are the main nitrogen supply in soil, through application of the mineral and organic fertilizers doses. In order to optimize the crop production in order to avoid the environmental contamination with nitrates, a nutrient management plan at the farm/village level was developed. The software is an useful tool for the farmer and/or local stakeholders, as well as for local authorities.

This dataset contains a Questionnaire used to evaluate the quality of the <... more This dataset contains a Questionnaire used to evaluate the quality of the Romanian Standard of colors for soil type map legends (StdCol) by map users and map designers. The Standard of colors resulted from the application of the specific method proposed by authors for developing reliably-distinguishable color schemes for legends of natural resource taxonomy-based maps. It was applied, in its turn, in developing the Dominant Soil Map of Romania at the 1:700,000 scale (DSM700). The Questionnaire contains the description of the Standard of colors, the items whose readability are to be evaluated (the color pairs of the Standard, the Standard as a whole, and two map excerpts), the guidelines of evaluation, and the requested general information regarding the evaluator. A table that presents the test/evaluation data that were obtained from 46 evaluators is given.

Carpathian Journal of Earth and Environmental Sciences, Jan 25, 2023

Research Journal of Agricultural Science, 2009

Carpathian Journal of Earth and Environmental Sciences, Feb 1, 2022

Annals of the University of Craiova - Agriculture, Montanology, Cadastre Series, Jan 4, 2023

Carpathian Journal of Earth and Environmental Sciences, Aug 31, 2022

Carpathian Journal of Earth and Environmental Sciences, Jan 25, 2023

"Annals of the University of Craiova - Agriculture Montanology Cadastre Series "

Journal of Environmental Protection and Ecology, 2016

SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings, 2011

AgroLife Scientific Journal, Jun 30, 2023

15th International Multidisciplinary Scientific GeoConference SGEM2015, INFORMATICS, GEOINFORMATICS AND REMOTE SENSING, 2011

Journal of Environmental Protection and Ecology, 2013

Research Journal of Agricultural Science, 2011

Research Journal of Agricultural Science, 2010

Annals of the …, 2010

soilscience.uaic.ro

Recently, the Joint Research Centre (JRC, Ispra) generated the content of a tentative USDA Soil T... more Recently, the Joint Research Centre (JRC, Ispra) generated the content of a tentative USDA Soil Textural Classes Map for Romania using advanced spatial interpolation models and the LUCAS-2009 dataset. The paper presents the main findings obtained by comparing this map with legacy soil data collected and analysed in Romania. The results show that more than 49 % soil delineations of the Vector Map of Romania’s Soils “SIGSTAR-200” are likely classified coherently in both the USDA and Romanian ICPA soil textural classifications. The results may be considered good because LUCAS-2009 did not contain soil data collected in Romania. They could be explained by proper soil-forming covariates and associated datasets, selected by JRC in the modelling phase, and by the fact that some of the pedotransfer rules implemented are relaxed (i.e., rarely occurring relations are also valid) in the optimistic scenario taken into consideration.