Organic agriculture reduces external inputs by controlling pests and diseases naturally, with bot... more Organic agriculture reduces external inputs by controlling pests and diseases naturally, with both traditional and modern methods. Official statistics indicate that in Romania, the organic sector is continuously growing within the last decade although research in organic farming is rather random. Field research has been performed in one of the first organic farms settled in Romania (S.A. Stepa, Stupina, Constanţa, certified since 2000 and complying at present to UE Council Regulation 837/2007), with the aim of assessing the agricultural practices impact on the soil physical and chemical state within a PNCD-2 Project 51-047 " Agri-environmental technologies to protect the quality of the soil environment, applied in some broad acre macro-zones in Romania-TACME ". The entire range of usual analyses were conducted for soil samples collected from five different agricultural plots, cropped differently, under farm's crop rotation plan. The analytical determinations included p...
The research performed at A.R.D.S. Teleorman, during 2000-2002, had as aim the determination of s... more The research performed at A.R.D.S. Teleorman, during 2000-2002, had as aim the determination of soil-water-plant-atmosphere interrelations, under optimum water supplying conditions (100%) and at different levels of induced hydric stress (dryland, irrigated 25%, 50%, 75% from optimum irrigation rate) in maize, with a view to reduce the irrigation water consumption on the clay-illuvial chernozem. Based on the obtained results, it has been ascertained that it is possible to achieve yields of 7,000-10,000 kg grain/ha by irrigation with limited water rates [50%, 75% respectively, from the optimum irrigation rate (50% active moisture interval)]. The pluviometric regime, non-uniformly distributed during the vegetation period, soil drought (induced hydric stress) associated with drought and heat rendered more difficult the polli-nation and grain formation. On an average, during the three years of experimentation, these conditions deter-mined a sterility degree between 3.0 and 23.4% with sma...
Today in Romania about 7 mil. ha are affected by drought as a limiting factor for crops. A modern... more Today in Romania about 7 mil. ha are affected by drought as a limiting factor for crops. A modern method possibly to be used at farm level in drought conditions is to incorporate superabsorbent materials in soils. These materials have the property to retain water, to further release it in conditions of water scarcity or precipitation lack over a longer interval, especially during the growing season of cultivated crops. The superabsorbent tested in this study is made of maize starch, is structurally made up of solid granules, is biodegradable and non-toxic and have the capacity to retain 500 times more water than their mass. The experimental sites were located in private farms in Pecica, Arad, in fields with onion and water melon crops and consisted of variants in which two doses of superabsorbent were applied (6 Kg/ha and 12 Kg/ha) and a control variant. The volume of soil water at rooting depth that is readily available to plants has a very important role in increasing plant produc...
Estimation of the soil physical quality of four agricultural soils from Bacău county was done by ... more Estimation of the soil physical quality of four agricultural soils from Bacău county was done by investigating different soil physical properties (bulk density, penetration resistance, saturated hydraulic conductivity, total porosity, soil water retention, S index). Data analysis showed that high penetration resistance and bulk density lead to formation of a compacted layer just below the ploughing depth. On the other hand, the tilled layers of the soil profiles had better hydraulic conductivity and porosity as compared with the deeper soil horizons. Organic matter content, clay content and bulk density influences the soil physical quality as quantified by S index, whereas only organic matter content and bulk density influences the saturated water content. In addition, it was found that the soil physical quality index, S, may be predicted by using pedotransfer functions. Introduction The concept of soil quality conservation is a central link in the development of management strategi...
This paper presents the soil water retention curves determined on two soil types from hydrographi... more This paper presents the soil water retention curves determined on two soil types from hydrographic basin of Arges River: P1 -Eutricambisol tipic, P2 -Vertisol stagni-pellic. Undisturbed soil cylinders were sampled on the genetic horizon depths characteristic for each soil type. The soil water retention curves were measured in the laboratory using standard equipment for retention measurements supplied by the Dutch Eijkelkamp company. The principle of the method is based on the determination of the soil water content corresponding to a certain level of water suction applied. By applying the Solver Microsoft Office Excel program the measured values of the water content from soil water retention curves were used to estimate the parameters of the van Genuchten equation which were later used to estimate the soil water retention curves and the main hidrophysical indices: field capacity (FC), wilting point (WP) and plant available water (PAW). The obtained results have illustrated the evide...
Water related biophysical indicators used today for the designation of less favoured areas for ag... more Water related biophysical indicators used today for the designation of less favoured areas for agriculture at European scale (e.g. growing days defined as the number of days with temperatures over 5 and ratio between actual soil available water and potential evapotranspiration over 0.5, various aridity indexes: Bagnouls-Gaussen, UNESCO) are evaluated at European scale using a crop water balance simulation model (ROIMPEL) linked with soil database 1:1,000,000 [1] and climate data for 1961-1990 baseline and 2020-2040 projections (ECHAM4, HADCM3). Each biophysical indicator shows various trends in space and time that impose a harmonisation for defining clear agriculture policies for drought management.
Because the soil water retention curve assessment requires (in terms of standardized European met... more Because the soil water retention curve assessment requires (in terms of standardized European methodology) long time for measuring all levels of the soil water suction applied, we have used an indirect estimation methodology (deterministic) in order to have an overview of the soil capacity to retain water at different levels, which correspond to the main soil hidrophysical indicators, particularly important in assessing soil fertility status, as characterized by the ability of soil to maintain water in soil, and release the water when there are needs and / or requirements for crop plants. In this paper we present the model of Arya - Paris, which assess the water retention curve using soil texture and bulk density data. This model is based on the analogy between the soil water retention curve and the cumulative distribution curve by soil particles size. Parameter α introduced by Arya and Paris is an effective way to assess the length of capillaries in natural soils using as a measure...
A large-scale biofuel production needs large land requirements, since most biofuel feedstock toda... more A large-scale biofuel production needs large land requirements, since most biofuel feedstock today are produced from crops that need productive land. The biofuel feedstock demand and the associated land requirements can have direct and indirect impacts, such as direct land use change (LUC) and indirect land use change (ILUC). The European Union Renewable Energy Directive and Fuel Quality Directive (FQD) include criteria for the prevention of unwanted direct land use change of feedstock production for biofuels. But these criteria do not focus on indirect land use change (ILUC). In order to identify low impacts of indirect land use changes for biofuel production low indirect impact biofuel (LIIB) methodology has been developed. The methodology comprises four ILUC mitigation solutions, one of them being that of biofuel feedstocks production on unused land with low carbon stocks and low biodiversity values. In this paper it is analyzed the potential for biofuel production on unused land...
Sunflower is the most important oil plant, being the third plant in oilseeds grass family, and be... more Sunflower is the most important oil plant, being the third plant in oilseeds grass family, and being used in food and food industry. Being a heat and light loving plant , it is cultivated in the corn areal and it is forbidden to follow plants consuming much water and nutrients. In the natural background conditions on the trial plot, and taking into account the improvement scheme, the sunflower was sowing in all the years of experimentation (1998-1999, 1999-2000, 2002-2003, 2003-2004), achieving high yields. Sunflower responded well under most treatments, the yields being similar to the ones obtained under irrigation and fertilization. The main purpose of the research was to pursue the influence of agrofitotechnical measures on soil and yields for the main field crops in the trial plot Lacu Sarat, Braila county, and, in this paper, the behaviour of the sunflower crop has been presented. Sunflowers (Helianthus annuus L.) is an annual herbaceous plant that is cultivated from almost 300...
14th SGEM GeoConference on WATER RESOURCES. FOREST, MARINE AND OCEAN ECOSYSTEMS, 2014
The soil water retention curve or the soil water content-matric potential relationship expresses ... more The soil water retention curve or the soil water content-matric potential relationship expresses the capacity of soils to store water for plant growth, which is a very important soil property for irrigation and hydrological modelling. Due to relatively long time involved in the determination of water retention curves, there is an increasing interest for models that estimate this property from simple taxonomic data (soil particle size distribution, bulk density, organic matter and other basic properties). Among these models is the Arya -Paris approach, which is based on the similarity between the shapes of particle size distribution and soil water retention curves. In this paper the model of Arya -Paris was used for assessing the water retention curve using soil texture and bulk density data. Arya-Paris model with α values calculated was applied to evaluate pairs of θ (soil water content) -ψ (matric potential). The van Genuchten equation was then used to estimate the water retention curve in the analyzed soils. Two soil types (Rendzic Leptosol and Calcaro-calcic Kastanozem) located in the Dobrogea area from SE of Romania were analyzed. Parameters of the van Genuchten equation, θr, θs, α, n were evaluated using the pairs of values θψ calculated by Arya-Paris model. Van Genuchten equation was then used to assess some parameters that have agronomical significance. Optimum soil water content and soil matric potential for soil workability correspond to the inflection point of the soil water retention curve. Depending on the characteristics of the soil water retention curve at the inflection point the soil physical quality index, S was calculated.
Six soil profiles were analyzed from the southern part of Oltenia, the area of sandy soils, from ... more Six soil profiles were analyzed from the southern part of Oltenia, the area of sandy soils, from the point of view of main physical and chemical characteristics and of the selenium abundance. Three of them are located around the Desa locality and three around the Dăbuleni locality. The predominance of coarse texture was established, along with a diverse reaction, from moderately acid to moderately alkaline, very low humus, total nitrogen, mobile phosphorus and potassium contents, and a low to extremely low total cation exchange capacity. The A horizon makes exception as its humus and total nitrogen contents are slightly increased. The total selenium contents of these soils oscillate between 20 and 190 μg·kg -1 , with a 97 μg·kg -1 average value, and the mobile selenium contents belong to the interval 5 to 41 μg·kg -1 , with a 22 μg·kg -1 average value. The soils of the Desa area have a total selenium content 2.1 times higher than those of the Dăbuleni area. On the other hand, the mo...
14th SGEM GeoConference on ENERGY AND CLEAN TECHNOLOGIES, 2014
Use of renewable energy resources is regulated by EU Directive 2009/28/CE from April 23 rd 2009. ... more Use of renewable energy resources is regulated by EU Directive 2009/28/CE from April 23 rd 2009. The reduction of the greenhouse gas emissions coming from the biofuels and bioliquids use is calculated according to the Article 19 of the Directive and is based on typical and default values. In this study the coefficients for rape crop (typical emissions of greenhouse gas -g CO 2 ech MJ -1 ) were evaluated at NUTS3 level (county) taking into account the pedoclimatic and technological conditions of Romania. The evaluation of greenhouse gas emissions and of energy consumptions within the whole production chain of biodiesel was done by using three different computing programs: Greenhouse Gas Calculator -version 2.1b/2008; Greenhouse Gas Calculator for bioethanol and biodiesel designed in 2005 by Environmental Policy Center of Imperial College from London and adapted to the Directive requirements in 2009; Carbon Calculator -version 1.1 designed by E4Tech for Renewable Fuels Agency from UK. These programs were used for different crop production levels: multiannual national average for the period of 1991-2011 provided by National Institute of Statistics; the lower level of crop production defined as difference between multiannual average and standard deviation of crop production years; the upper level of the crop production defined as sum between multiannual average and standard deviation of crop production years; crop production for which the default values of crop coefficients are given in Annex V/part D. The aggregation of information on greenhouse gas emissions (g CO 2 ech MJ -1 ) at NUTS3 level corresponding to the fourth levels of crop production was done as an average of emissions from each soil-terrain unit under arable land use. The results obtained using three computing programs showed that the dependence between greenhouse gas emissions specific to rape crop (g CO 2 ech MJ -1 ) and crop yield (t ha -1 ) are similar. The E4Tech model was then used for evaluation of spatial distribution of emissions. It was used the dependence between typical greenhouse gas emissions specific to rape crop and crop yield (optimum technology: multiannual average, multiannual average ± standard deviation; actual technology: multiannual average). The aggregation of these results at NUTS3 level showed that in the case of optimum technology most of the counties with arable land use have average values ranging within the default values for typical emissions included in the Directive. In case of actual technology, the average counties values of greenhouse gas emissions for the entire production cycle of biodiesel obtained from rape (based on the average production of rape at national level for the 14 th International Multidisciplinary Scientific GeoConference SGEM 2014 1991-2011 period) are much higher than the typical and default values given in Annex V/part A of the Directive. In case of crop production obtained in favorable years (average production + standard deviation) and in optimum technology the average values are regularly lower than typical and default values from the Directive. In case of non-favorable years (average production -standard deviation) and in optimum technology all counties have average values of greenhouse gas emissions higher than typical and default values from Directive.
14th SGEM GeoConference on WATER RESOURCES. FOREST, MARINE AND OCEAN ECOSYSTEMS, 2014
Today in Romania about 7 mil. ha are affected by drought as a limiting factor for crops. A modern... more Today in Romania about 7 mil. ha are affected by drought as a limiting factor for crops. A modern method possibly to be used at farm level in drought conditions is to incorporate superabsorbent materials in soils. These materials have the property to retain water, to further release it in conditions of water scarcity or precipitation lack over a longer interval, especially during the growing season of cultivated crops. The superabsorbent tested in this study is made of maize starch, is structurally made up of solid granules, is biodegradable and non-toxic and have the capacity to retain 500 times more water than their mass. The experimental sites were located in private farms in Pecica, Arad, in fields with oat, onion and water melon crops and consisted of variants in which two doses of superabsorbent were applied (6 Kg/ha and 12 Kg/ha) and a control variant. The volume of soil water at rooting depth that is readily available to plants has a very important role in increasing plant productivity and was measured by determining the soil water retention capacity. Water retention measurements were done on undisturbed soil samples at three depths (5-10 cm, 15-20 cm, 25-30 cm) using laboratory standardized equipments. Measured values of soil moisture are used for calculating the van Genuchten equation parameters and then soil water retention curves were estimated. Study results showed that mobility and availability of water are higher in treated variants than in the control one as a result of superabsorbent application in top-soil layers. Highest values of plant available water were recorded in variant where 12 kg of superabsorbent was applied in oat and onion fields at 15 -20 cm depth, whereas in water melon field the highest value for available water was determined in variant with 12 kg of superabsorbent at 5 -10 cm depth. Also it was noticed that in oat field in the variant with 12 kg of Zeba applied, at 15-20 cm depth, in onion field in variant with 12 kg of superabsorbent, at 5-10 cm and 15-20 cm depths and in water melon field in variant with 12 kg of superabsorbent, at 5-10 cm and 25-30 cm depths, the water is strongly retained in soil at lower levels of suction, whereas at pF values higher than 2.5 the water retained in soil starts to be slowly released during the drought periods, when there is no any water supply.
The land an agriculture monitoring system in Alba County includes 17 sites. The first determinati... more The land an agriculture monitoring system in Alba County includes 17 sites. The first determination was in 1994 and the second was realised in 2005. Every site was characterised from a morphological, physical and chemical point of view. Also, the content of heavy metals and total DDT and total HCH were determined. Research showed that the most af the sites belong to the slightly acid class on the 0-20 cm depth and neutral class on the 0-50 cm depth. The average content of organic matter, total nitrogen, and mobile potassium is moderate. The mobile phosphorus average content is low. The average contents of Cu, Zn, Ni and total HCH are higher than normal contents accepted by legislation. The other heavy metals belong to the normal class.
Abstract: The paper attempts to assess the impact of some conventional agricultural practices upo... more Abstract: The paper attempts to assess the impact of some conventional agricultural practices upon physical, chemical and biological soil state within two areas of SA Agroterra Agigea, located in Constanta county. Two expeditionary studies were organized in fields under relatively ...
Pollution caused by crude oil is the most prevalent problem in the environment. The release of cr... more Pollution caused by crude oil is the most prevalent problem in the environment. The release of crude oil into the environment by oil spills is receiving worldwide attention. The effect of crude oil pollution on soil properties was investigated by achieving a case study in ...
During non-ferrous metallurgical plant from Zlatna were emitted into the air both sulfur dioxide ... more During non-ferrous metallurgical plant from Zlatna were emitted into the air both sulfur dioxide and powder of metal sulphides and metal oxides. Dioxide and trioxide sulfur in contact with rain water converts to sulfuric acid that leading to the formation of acid precipitation, which in contact with soils lead to its acidification. Acid soils have less favorable physical properties including poorly formed or damaged structure. In this paper is studied the influence of soil acidification on some physical properties as water stable aggregates and dispersion. In the reserached area, the water stable aggregates of soils range in the field of small-very large values, with median belongs to moderate class values and only 10% had values that belong to high and very high classes. In the soils investigated from Zlatna area, the water stable aggregates is significant, respectively, very significantly influenced by the soil physical and chemical properties as: clay, content of humus, Ca 2+ ions, percentage of base saturation, sum of exchangeable bases, soil reaction, and cation exchange capacity. Lowest correlation was established with soil reaction (r=0.338*) and the strongest correlation was with total cation exchange capacity (r=0.756***). Dispersion ranges in the field of low-very high values and over 75% of the values belong to classes of high-very high values.
Organic agriculture reduces external inputs by controlling pests and diseases naturally, with bot... more Organic agriculture reduces external inputs by controlling pests and diseases naturally, with both traditional and modern methods. Official statistics indicate that in Romania, the organic sector is continuously growing within the last decade although research in organic farming is rather random. Field research has been performed in one of the first organic farms settled in Romania (S.A. Stepa, Stupina, Constanţa, certified since 2000 and complying at present to UE Council Regulation 837/2007), with the aim of assessing the agricultural practices impact on the soil physical and chemical state within a PNCD-2 Project 51-047 " Agri-environmental technologies to protect the quality of the soil environment, applied in some broad acre macro-zones in Romania-TACME ". The entire range of usual analyses were conducted for soil samples collected from five different agricultural plots, cropped differently, under farm's crop rotation plan. The analytical determinations included p...
The research performed at A.R.D.S. Teleorman, during 2000-2002, had as aim the determination of s... more The research performed at A.R.D.S. Teleorman, during 2000-2002, had as aim the determination of soil-water-plant-atmosphere interrelations, under optimum water supplying conditions (100%) and at different levels of induced hydric stress (dryland, irrigated 25%, 50%, 75% from optimum irrigation rate) in maize, with a view to reduce the irrigation water consumption on the clay-illuvial chernozem. Based on the obtained results, it has been ascertained that it is possible to achieve yields of 7,000-10,000 kg grain/ha by irrigation with limited water rates [50%, 75% respectively, from the optimum irrigation rate (50% active moisture interval)]. The pluviometric regime, non-uniformly distributed during the vegetation period, soil drought (induced hydric stress) associated with drought and heat rendered more difficult the polli-nation and grain formation. On an average, during the three years of experimentation, these conditions deter-mined a sterility degree between 3.0 and 23.4% with sma...
Today in Romania about 7 mil. ha are affected by drought as a limiting factor for crops. A modern... more Today in Romania about 7 mil. ha are affected by drought as a limiting factor for crops. A modern method possibly to be used at farm level in drought conditions is to incorporate superabsorbent materials in soils. These materials have the property to retain water, to further release it in conditions of water scarcity or precipitation lack over a longer interval, especially during the growing season of cultivated crops. The superabsorbent tested in this study is made of maize starch, is structurally made up of solid granules, is biodegradable and non-toxic and have the capacity to retain 500 times more water than their mass. The experimental sites were located in private farms in Pecica, Arad, in fields with onion and water melon crops and consisted of variants in which two doses of superabsorbent were applied (6 Kg/ha and 12 Kg/ha) and a control variant. The volume of soil water at rooting depth that is readily available to plants has a very important role in increasing plant produc...
Estimation of the soil physical quality of four agricultural soils from Bacău county was done by ... more Estimation of the soil physical quality of four agricultural soils from Bacău county was done by investigating different soil physical properties (bulk density, penetration resistance, saturated hydraulic conductivity, total porosity, soil water retention, S index). Data analysis showed that high penetration resistance and bulk density lead to formation of a compacted layer just below the ploughing depth. On the other hand, the tilled layers of the soil profiles had better hydraulic conductivity and porosity as compared with the deeper soil horizons. Organic matter content, clay content and bulk density influences the soil physical quality as quantified by S index, whereas only organic matter content and bulk density influences the saturated water content. In addition, it was found that the soil physical quality index, S, may be predicted by using pedotransfer functions. Introduction The concept of soil quality conservation is a central link in the development of management strategi...
This paper presents the soil water retention curves determined on two soil types from hydrographi... more This paper presents the soil water retention curves determined on two soil types from hydrographic basin of Arges River: P1 -Eutricambisol tipic, P2 -Vertisol stagni-pellic. Undisturbed soil cylinders were sampled on the genetic horizon depths characteristic for each soil type. The soil water retention curves were measured in the laboratory using standard equipment for retention measurements supplied by the Dutch Eijkelkamp company. The principle of the method is based on the determination of the soil water content corresponding to a certain level of water suction applied. By applying the Solver Microsoft Office Excel program the measured values of the water content from soil water retention curves were used to estimate the parameters of the van Genuchten equation which were later used to estimate the soil water retention curves and the main hidrophysical indices: field capacity (FC), wilting point (WP) and plant available water (PAW). The obtained results have illustrated the evide...
Water related biophysical indicators used today for the designation of less favoured areas for ag... more Water related biophysical indicators used today for the designation of less favoured areas for agriculture at European scale (e.g. growing days defined as the number of days with temperatures over 5 and ratio between actual soil available water and potential evapotranspiration over 0.5, various aridity indexes: Bagnouls-Gaussen, UNESCO) are evaluated at European scale using a crop water balance simulation model (ROIMPEL) linked with soil database 1:1,000,000 [1] and climate data for 1961-1990 baseline and 2020-2040 projections (ECHAM4, HADCM3). Each biophysical indicator shows various trends in space and time that impose a harmonisation for defining clear agriculture policies for drought management.
Because the soil water retention curve assessment requires (in terms of standardized European met... more Because the soil water retention curve assessment requires (in terms of standardized European methodology) long time for measuring all levels of the soil water suction applied, we have used an indirect estimation methodology (deterministic) in order to have an overview of the soil capacity to retain water at different levels, which correspond to the main soil hidrophysical indicators, particularly important in assessing soil fertility status, as characterized by the ability of soil to maintain water in soil, and release the water when there are needs and / or requirements for crop plants. In this paper we present the model of Arya - Paris, which assess the water retention curve using soil texture and bulk density data. This model is based on the analogy between the soil water retention curve and the cumulative distribution curve by soil particles size. Parameter α introduced by Arya and Paris is an effective way to assess the length of capillaries in natural soils using as a measure...
A large-scale biofuel production needs large land requirements, since most biofuel feedstock toda... more A large-scale biofuel production needs large land requirements, since most biofuel feedstock today are produced from crops that need productive land. The biofuel feedstock demand and the associated land requirements can have direct and indirect impacts, such as direct land use change (LUC) and indirect land use change (ILUC). The European Union Renewable Energy Directive and Fuel Quality Directive (FQD) include criteria for the prevention of unwanted direct land use change of feedstock production for biofuels. But these criteria do not focus on indirect land use change (ILUC). In order to identify low impacts of indirect land use changes for biofuel production low indirect impact biofuel (LIIB) methodology has been developed. The methodology comprises four ILUC mitigation solutions, one of them being that of biofuel feedstocks production on unused land with low carbon stocks and low biodiversity values. In this paper it is analyzed the potential for biofuel production on unused land...
Sunflower is the most important oil plant, being the third plant in oilseeds grass family, and be... more Sunflower is the most important oil plant, being the third plant in oilseeds grass family, and being used in food and food industry. Being a heat and light loving plant , it is cultivated in the corn areal and it is forbidden to follow plants consuming much water and nutrients. In the natural background conditions on the trial plot, and taking into account the improvement scheme, the sunflower was sowing in all the years of experimentation (1998-1999, 1999-2000, 2002-2003, 2003-2004), achieving high yields. Sunflower responded well under most treatments, the yields being similar to the ones obtained under irrigation and fertilization. The main purpose of the research was to pursue the influence of agrofitotechnical measures on soil and yields for the main field crops in the trial plot Lacu Sarat, Braila county, and, in this paper, the behaviour of the sunflower crop has been presented. Sunflowers (Helianthus annuus L.) is an annual herbaceous plant that is cultivated from almost 300...
14th SGEM GeoConference on WATER RESOURCES. FOREST, MARINE AND OCEAN ECOSYSTEMS, 2014
The soil water retention curve or the soil water content-matric potential relationship expresses ... more The soil water retention curve or the soil water content-matric potential relationship expresses the capacity of soils to store water for plant growth, which is a very important soil property for irrigation and hydrological modelling. Due to relatively long time involved in the determination of water retention curves, there is an increasing interest for models that estimate this property from simple taxonomic data (soil particle size distribution, bulk density, organic matter and other basic properties). Among these models is the Arya -Paris approach, which is based on the similarity between the shapes of particle size distribution and soil water retention curves. In this paper the model of Arya -Paris was used for assessing the water retention curve using soil texture and bulk density data. Arya-Paris model with α values calculated was applied to evaluate pairs of θ (soil water content) -ψ (matric potential). The van Genuchten equation was then used to estimate the water retention curve in the analyzed soils. Two soil types (Rendzic Leptosol and Calcaro-calcic Kastanozem) located in the Dobrogea area from SE of Romania were analyzed. Parameters of the van Genuchten equation, θr, θs, α, n were evaluated using the pairs of values θψ calculated by Arya-Paris model. Van Genuchten equation was then used to assess some parameters that have agronomical significance. Optimum soil water content and soil matric potential for soil workability correspond to the inflection point of the soil water retention curve. Depending on the characteristics of the soil water retention curve at the inflection point the soil physical quality index, S was calculated.
Six soil profiles were analyzed from the southern part of Oltenia, the area of sandy soils, from ... more Six soil profiles were analyzed from the southern part of Oltenia, the area of sandy soils, from the point of view of main physical and chemical characteristics and of the selenium abundance. Three of them are located around the Desa locality and three around the Dăbuleni locality. The predominance of coarse texture was established, along with a diverse reaction, from moderately acid to moderately alkaline, very low humus, total nitrogen, mobile phosphorus and potassium contents, and a low to extremely low total cation exchange capacity. The A horizon makes exception as its humus and total nitrogen contents are slightly increased. The total selenium contents of these soils oscillate between 20 and 190 μg·kg -1 , with a 97 μg·kg -1 average value, and the mobile selenium contents belong to the interval 5 to 41 μg·kg -1 , with a 22 μg·kg -1 average value. The soils of the Desa area have a total selenium content 2.1 times higher than those of the Dăbuleni area. On the other hand, the mo...
14th SGEM GeoConference on ENERGY AND CLEAN TECHNOLOGIES, 2014
Use of renewable energy resources is regulated by EU Directive 2009/28/CE from April 23 rd 2009. ... more Use of renewable energy resources is regulated by EU Directive 2009/28/CE from April 23 rd 2009. The reduction of the greenhouse gas emissions coming from the biofuels and bioliquids use is calculated according to the Article 19 of the Directive and is based on typical and default values. In this study the coefficients for rape crop (typical emissions of greenhouse gas -g CO 2 ech MJ -1 ) were evaluated at NUTS3 level (county) taking into account the pedoclimatic and technological conditions of Romania. The evaluation of greenhouse gas emissions and of energy consumptions within the whole production chain of biodiesel was done by using three different computing programs: Greenhouse Gas Calculator -version 2.1b/2008; Greenhouse Gas Calculator for bioethanol and biodiesel designed in 2005 by Environmental Policy Center of Imperial College from London and adapted to the Directive requirements in 2009; Carbon Calculator -version 1.1 designed by E4Tech for Renewable Fuels Agency from UK. These programs were used for different crop production levels: multiannual national average for the period of 1991-2011 provided by National Institute of Statistics; the lower level of crop production defined as difference between multiannual average and standard deviation of crop production years; the upper level of the crop production defined as sum between multiannual average and standard deviation of crop production years; crop production for which the default values of crop coefficients are given in Annex V/part D. The aggregation of information on greenhouse gas emissions (g CO 2 ech MJ -1 ) at NUTS3 level corresponding to the fourth levels of crop production was done as an average of emissions from each soil-terrain unit under arable land use. The results obtained using three computing programs showed that the dependence between greenhouse gas emissions specific to rape crop (g CO 2 ech MJ -1 ) and crop yield (t ha -1 ) are similar. The E4Tech model was then used for evaluation of spatial distribution of emissions. It was used the dependence between typical greenhouse gas emissions specific to rape crop and crop yield (optimum technology: multiannual average, multiannual average ± standard deviation; actual technology: multiannual average). The aggregation of these results at NUTS3 level showed that in the case of optimum technology most of the counties with arable land use have average values ranging within the default values for typical emissions included in the Directive. In case of actual technology, the average counties values of greenhouse gas emissions for the entire production cycle of biodiesel obtained from rape (based on the average production of rape at national level for the 14 th International Multidisciplinary Scientific GeoConference SGEM 2014 1991-2011 period) are much higher than the typical and default values given in Annex V/part A of the Directive. In case of crop production obtained in favorable years (average production + standard deviation) and in optimum technology the average values are regularly lower than typical and default values from the Directive. In case of non-favorable years (average production -standard deviation) and in optimum technology all counties have average values of greenhouse gas emissions higher than typical and default values from Directive.
14th SGEM GeoConference on WATER RESOURCES. FOREST, MARINE AND OCEAN ECOSYSTEMS, 2014
Today in Romania about 7 mil. ha are affected by drought as a limiting factor for crops. A modern... more Today in Romania about 7 mil. ha are affected by drought as a limiting factor for crops. A modern method possibly to be used at farm level in drought conditions is to incorporate superabsorbent materials in soils. These materials have the property to retain water, to further release it in conditions of water scarcity or precipitation lack over a longer interval, especially during the growing season of cultivated crops. The superabsorbent tested in this study is made of maize starch, is structurally made up of solid granules, is biodegradable and non-toxic and have the capacity to retain 500 times more water than their mass. The experimental sites were located in private farms in Pecica, Arad, in fields with oat, onion and water melon crops and consisted of variants in which two doses of superabsorbent were applied (6 Kg/ha and 12 Kg/ha) and a control variant. The volume of soil water at rooting depth that is readily available to plants has a very important role in increasing plant productivity and was measured by determining the soil water retention capacity. Water retention measurements were done on undisturbed soil samples at three depths (5-10 cm, 15-20 cm, 25-30 cm) using laboratory standardized equipments. Measured values of soil moisture are used for calculating the van Genuchten equation parameters and then soil water retention curves were estimated. Study results showed that mobility and availability of water are higher in treated variants than in the control one as a result of superabsorbent application in top-soil layers. Highest values of plant available water were recorded in variant where 12 kg of superabsorbent was applied in oat and onion fields at 15 -20 cm depth, whereas in water melon field the highest value for available water was determined in variant with 12 kg of superabsorbent at 5 -10 cm depth. Also it was noticed that in oat field in the variant with 12 kg of Zeba applied, at 15-20 cm depth, in onion field in variant with 12 kg of superabsorbent, at 5-10 cm and 15-20 cm depths and in water melon field in variant with 12 kg of superabsorbent, at 5-10 cm and 25-30 cm depths, the water is strongly retained in soil at lower levels of suction, whereas at pF values higher than 2.5 the water retained in soil starts to be slowly released during the drought periods, when there is no any water supply.
The land an agriculture monitoring system in Alba County includes 17 sites. The first determinati... more The land an agriculture monitoring system in Alba County includes 17 sites. The first determination was in 1994 and the second was realised in 2005. Every site was characterised from a morphological, physical and chemical point of view. Also, the content of heavy metals and total DDT and total HCH were determined. Research showed that the most af the sites belong to the slightly acid class on the 0-20 cm depth and neutral class on the 0-50 cm depth. The average content of organic matter, total nitrogen, and mobile potassium is moderate. The mobile phosphorus average content is low. The average contents of Cu, Zn, Ni and total HCH are higher than normal contents accepted by legislation. The other heavy metals belong to the normal class.
Abstract: The paper attempts to assess the impact of some conventional agricultural practices upo... more Abstract: The paper attempts to assess the impact of some conventional agricultural practices upon physical, chemical and biological soil state within two areas of SA Agroterra Agigea, located in Constanta county. Two expeditionary studies were organized in fields under relatively ...
Pollution caused by crude oil is the most prevalent problem in the environment. The release of cr... more Pollution caused by crude oil is the most prevalent problem in the environment. The release of crude oil into the environment by oil spills is receiving worldwide attention. The effect of crude oil pollution on soil properties was investigated by achieving a case study in ...
During non-ferrous metallurgical plant from Zlatna were emitted into the air both sulfur dioxide ... more During non-ferrous metallurgical plant from Zlatna were emitted into the air both sulfur dioxide and powder of metal sulphides and metal oxides. Dioxide and trioxide sulfur in contact with rain water converts to sulfuric acid that leading to the formation of acid precipitation, which in contact with soils lead to its acidification. Acid soils have less favorable physical properties including poorly formed or damaged structure. In this paper is studied the influence of soil acidification on some physical properties as water stable aggregates and dispersion. In the reserached area, the water stable aggregates of soils range in the field of small-very large values, with median belongs to moderate class values and only 10% had values that belong to high and very high classes. In the soils investigated from Zlatna area, the water stable aggregates is significant, respectively, very significantly influenced by the soil physical and chemical properties as: clay, content of humus, Ca 2+ ions, percentage of base saturation, sum of exchangeable bases, soil reaction, and cation exchange capacity. Lowest correlation was established with soil reaction (r=0.338*) and the strongest correlation was with total cation exchange capacity (r=0.756***). Dispersion ranges in the field of low-very high values and over 75% of the values belong to classes of high-very high values.
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Papers by Irina Calciu