Mohsen Soleimanzadeh; Hossein Khademi; mozhgan sepehri
Abstract
Introduction: Iron is one of the essential micronutrients for plant growth. The total amount of iron in soil is often more than plant iron requirement, but the low solubility of iron compounds in many of soils leads to low uptake of this element by plant and eventually, results in iron deficiency symptoms ...
Read More
Introduction: Iron is one of the essential micronutrients for plant growth. The total amount of iron in soil is often more than plant iron requirement, but the low solubility of iron compounds in many of soils leads to low uptake of this element by plant and eventually, results in iron deficiency symptoms in plant. Iron is the structural component of cytochromes, leghemoglobines and ferredoxins. This element participates in many vital activities of plants, such as photosynthesis, respiration and fixation of molecular nitrogen. Some of micaceous minerals including muscovite and phlogopite which contain significant amounts of iron are plentiful in soils of arid and semiarid regions of Iran. The purpose of this study was to evaluate the ability of two plant species (alfalfa and barley) to uptake structural iron from muscovite and phlogopite.
Materials and Methods: The greenhouse experiment was conducted as factorial arrangement based on completely randomized design with three replicates. Treatments consisted of two plant species (alfalfa and barley), two types of micaceous minerals (phlogopite and muscovite) and two nutrient solutions (complete and iron-free).The experiment was done in 700 g pots containing a mixture of quartz sand (as the filling material), cocopeat and micaceous minerals (phlogopite and muscovite). Quartz sand and micaceous mineral were obtained from a mine near Hamadan City in Iran. For this purpose, X-ray elemental analysis fluorescence (XRF) was used to investigate the possibility of using quartz sand and micaceous mineral. Micaceous minerals were passed through a 140 mesh sieve and then, samples were saturated with Ca using a 0.5 M CaCl2 solution. To remove the excess Cl, saturated minerals were washed with distilled water several times and then samples were oven dried at 105 °C. Pots were filled with a mixture of 600 g quartz sand, micaceous mineral and cocopeat. The amount of mineral was added until there was 0.35% K2O in all pots. Two barley and alfalfa seeds were planted in each pot. During the growth period (150days), plants were irrigated and fed with distilled water and nutrient solutions, respectively. At the end of the growth period, shoots and roots of plants were harvested andiron contents of plants extracts were measured by atomic absorption.
Results and Discussion: For two plant species, the results showed that iron concentration in the pots containing phlogopite and fed with iron-free nutrient solution was in a sufficient range for both barley and alfalfa. The amount of iron uptake by alfalfa in both substrates and nutrition solutions was more than barely. It seems that alfalfa is able to uptake more amount of iron due to the abundant root exudates. The highest amount of iron uptake by root is related to alfalfa cultivated in substrates containing phlogopite and fed with iron-free nutrient solution. The highest barley shoots weight is related to substrates containing phlogopite and muscovite fed with complete (with iron) nutrient solution, whereas in alfalfa, the highest shoot weight is related to phlogopite-containing substrates fed with iron-free nutrient solution. Plants cultivated in two substrates containing phlogopite and muscovite did not show deficiency symptoms until late growth period and appearance of plants fed with iron-free nutrient solution was completely similar to those fed with complete nutrient solution. The amount of iron uptake by roots is several times higher than that of shoots. High uptake of iron by plant roots are affected by phytosiderophores produced by plant roots. Phytosiderophores produce chelate Fe (III) in the rhizosphere. These chelates are absorbed into the apoplast of roots and Fe (III) is separated from them as a result of certain reactions, and takes the path to xylem.
Conclusion: The results of this study indicate that iron structural phlogopite and muscovite minerals can provide iron requirement for plant during the growth season. Since phlogopiteis a tri-octahedral mineral, it has more Fe (II) and its structure is weaker than muscovite, and hence, is able to provide more iron for the plant during growth season. But muscovite is di-octahedral and its structure contains Al+3, so octahedral may not easily release its elements into the rhizosphere for the plants utilization. The factors influence the release of elements from micaceous minerals are structure and type of mineral. Alfalfa is able to release more iron from micaceous minerals thanks to its root systems and ability to produce more shoot. Since micaceous minerals have considerable amount of iron and are able to provide iron requirement for plant during growth season, it is recommended to investigate whether micaceous minerals are able to supply this element for longer growth periods.
Ali Afshari; H. Khademi; shamsollah Ayoubi
Abstract
Introduction: Heavy metals are found to be one of the major environmental hazardous contaminants, for human health, animal life, air quality and other components of environment. They can affect geochemical cycles and accumulate in animal tissues since physical processes are not able to remove them, so ...
Read More
Introduction: Heavy metals are found to be one of the major environmental hazardous contaminants, for human health, animal life, air quality and other components of environment. They can affect geochemical cycles and accumulate in animal tissues since physical processes are not able to remove them, so they are consistent in long term. The analysis of the total concentration of heavy metals in soil may provide information about soils enrichment but in general, it is widely used to determine the potential mobility of heavy metals in environmental behavior under chemical forms of metals in soils. Heavy metals existat several phases including water-soluble, exchangeable, bounded to organic matter, bounded to carbonates, bounded to Fe-Mn oxides, secondary clay minerals and residual fraction within primary minerals network. There is a dynamic equilibrium between different fractions of elements in soil. The main objectives of the present study were a) The analysis of the total concentration of heavy metals such as Fe, Mn, Ni, Cr, Co, Pb, Zn, Cd and Cu and b) The fractionations of heavy metals and identification of controlling factors to distribution and behavior of heavy metals in soils at different land uses.
Materials and Methods: The study was performed at central area of Zanjan province (Iran). The study area was over 2000 km2 in coordinates 20´ 36° to 41´ 36° E and 19´ 48° to 53´ 48° N. The average altitudes were over 1500 meters above sea level. The major land uses of the study area included agriculture (AG), rangeland (RA) and urban (UR). Sample collection was done based on the random grid method in August 2011. Surface soil samples (0-10 cm depth) were taken from grid centers included 137, 77 and 27 samples from AG, RA and UR land uses, respectively. The samples were digested in Nitric acid 5 normal (Sposito et al., 1982) and total concentration of Pb, Zn, Ni, Mn, Cu, Cr, Fe and Co were measured by Perkin-Elmer: AA 200 atomic absorption instrument and cadmium was measured by atomic absorption equipped with Rayleigh: WF-1E graphite furnace. 75 soil samples were selected, DTPA-extraction and sequential extraction were performed and physiochemical characteristics of these samples analyzed. To extract the metals by DTPA, the method developed by Lindsay and Norvell, (1978) was used and sequential extraction was done by Tessier et al., (1979) method. All statistical parameters were calculated using SPSS 16.0 software, and mean comparison (mean separation) was carried out using Duncan test at probability level of 5%.
Results and Discussion: The results indicated that heavy metals concentrations and patterns were evidently affected by different land uses. Co concentration was between 17.0 – 35.7 mg/kg and had the lowest total coefficient of variation (14%). The maximum total Cr and Ni values were measured in AG land use (26.1 and 52.6 mg/kg, respectively) and lowest was in UR land use (17.0 and 37.2 mg/kg, respectively). The highest total average value of Mn was found in RA (698.9 mg/kg) and the lowest in UR (629.1mg/kg) land use. The highest Fe concentrations were measured in AG and RA land uses (17.2 and 17.0 g/kg, respectively) and the lowest in UR land use (14.0 g/kg). The maximum Concentration of total Cd was observed in UR land use (2.47 mg/kg) and its minimum values were found in RA and AG (0.83 and 0.75 mg/kg, respectively) in the study area. In UR land use, Cu and Zn were more significant than AG and RA land uses. Pb variation was the same as Zn so that its increased concentration was found in urban land use (90.2 to 1357.5 on average 220.1 mg/kg). The highest Pb values were measured in UR land use (220 mg/kg) while the lowest concentrations were found in RA and AG land uses (80.6 and 69.0 mg/kg, respectively).
Different elements showed various fractional distribution in different land uses. The highest Co percentage was related to residual fraction at all land uses, with values up to 48.4%, 54.0% and 48.1% in AG, RA and UR land uses, respectively. Ni fractionation had approximately the same pattern with Co in all factions and land uses, except exchangeable fraction of Ni that showed the lowest percentage in all land uses. The dominant fraction of Cu was residual fraction with the amounts of 73.3% 76.0% and 61.9% in AG, RA and UR land uses, respectively. The second dominant fraction in UR and AG land uses was related to that was bounded to OM, with 16.5% and 10.1%, respectively. Zn distribution in the AG and RA land uses had the same trend: Residual>bounded to Fe-Mn oxides>bounded to OM>bounded to carbonate>exchangeable fraction. Whereas, Zn distribution showed different trend in UR land use as bounded to Fe-Mn oxides>residual>bounded to carbonate>bounded to OM>exchangeable fraction. Pb distribution was different in each land use. Pb showed similar distribution to Zn in UR. In AG and RA land uses residual fraction of Pb was measured as highest value while other fractions of Pb had these distributions: Pb bounded to carbonate>bounded to Fe-Mn oxides>exchangeable >bounded to OM fraction in AG land use and Pb bounded to Fe-Mn oxides>bounded to OM>bounded to carbonate>exchangeable fraction in RA land use.
Conclusion: Based on the results of this study, Cr, Co, Ni, Mn and Fe magnitudes are uneven in soils. The total heavy metal concentrations fractionation can provide information on the contaminant metals sources. High levels of exchangeable fractions, acid soluble and easily reducible perhaps indicates anthropogenic activities. Naturally, Chemicals are associated to resistant soil fractions such as oxy hydroxides, organic matter and sulfides. In soil fractionation, the contribution of each fraction in soil was a function of metal type and land uses. Those metals were affected by anthropogenic activities such as lead, zinc, and partly copper, showed the highest percentage in the fraction that influenced by external input sources. Those were characterized by lithogenic origin (cobalt and nickel) was mainly found to be highest in residual fraction. However, in all metals, those fractions affected by anthropogenic activities (non-resistant fractions) were much more in urban land use than agriculture and rangeland ones.
A. Afshari; H. Khademi; P. Alamdari
Abstract
Introduction: Soil forms a thin layer over the surface of the earth that performs many essential life processes . Soil has always been important to humans and their health, providing a resource that can be used for shelter and food production. Higher heavy metals concentration within soils has beenshown ...
Read More
Introduction: Soil forms a thin layer over the surface of the earth that performs many essential life processes . Soil has always been important to humans and their health, providing a resource that can be used for shelter and food production. Higher heavy metals concentration within soils has beenshown to be toxic for human bodies, since they might be broken out easily via dust or direct contact through trophic levels. In addition long term heavy metals recalcitrance in soil results in low potential of soil productivity . Heavy metals interact complicatedly in soil. The present study was conducted in large scale by analyzing elements Mn, Co, Ni, Zn, Pb, Cd and Cu in soils in central lands of Zanjan province. The main objectives of present research were to investigate heavy metals diffusion and total contamination status in soil and determination of their possible origin using multivariate analysis.
Materials and Methods: This research was conducted in central lands located in Zanjan province (northwest of Iran). In terms of the main land uses, study area may involve farmlands, rangelands, urbanized and industrial lands. Study sites are totally covered 2000 km2 in coordinates of 36.20 to 36.41 N latitude and 48.19 to 48.53 E longitude. Sampling was conducted based on gridding method in randomized manner in August 2011. Urban lands affected by much anthropogenic activities and farm and rangelands together were placed in grids of 1.5×x 1.5 and 3×3 km2 respectively. Totally number of 241 soil samples (0-10 cm depth) was taken. Soil specimen's digestions were conducted using nitric acid 5 normal. Total elements concentration of Pb, Zn, Ni, Mn, Cu, Cr, Fe and Co were measured using Atomic adsorption device Perkin-Elmer: AA 200 and Cd concentration was determined by Atomic adsorption device equipped with graphic furnace model Rayleigh: WF-1E. Mean separation analysis of parameters (Pearson and spearman) was conducted using Duncan test in probability level of 5%. Principle component analysis (PCA) and hierarchical cluster analysis (HCA) were used to classify metals group. Achieving a simple structure and better results interpretation, data rotation in varimax type was conducted in PCA algorithm. Before cluster analysis, data were standardized and subsequently exposed to cluster analysis and plotting dendrogram, Euclidean approach was applied.
Results and Discussion Multivariate analysis (PCA, CA and CM) have been shown as an efficient tool to identify heavy metals origins, helping us in better data comprehension and interpretation. Results obtained on multivariate analysis approaches might are promising to distinguish polluted area and heavy metals potential origin, in turns indicating soil environmental quality.
PCA is known as an efficient method to determine anthropogenic impacts on a spatial scale and it may be essential to specify heavy metals contamination degree in respect to anthropogenic and litogenic contribution. As it illustrated, heavy metals are categorized in three-component model framework, accounting for 67% of total data variations. In rotated component matrix the first PC (PC1, 30% of variance) involves Ni, Cr, Co, Mn and Fe, while the second PC (PC2, 19% of variance) involves Zn and Pb and eventually the third one (PC3, 18% of variance) covers Cu and Cd among others. PC1 can be introduced as geological component because of its less coefficient of variations than others, skewedness less than 1 and normalized data status. It denotes lithogenic distribution of these metals in area. Furthermore,as above mentioned, the average heavy metalconcentrations werefound to be less than calculated background threshold. Because of their increased concentration in soil, high coefficient of variations and very high concentration than background threshold level as well as positive skewedness in heavy metals, PC2 and PC3 can be defined to antropogenical components. Atmospheric precipitation (deposition) serves as one of the main anthropogenic source of heavy metals pollution in the soil samples near theintense transportation traffic roads, accumulation site of factories solidwaters, energy generation process, metal melting, construction and traffic breaking out in whole area. Our results are in line with enormous findings on farming operations as the main factor that cause changes in Cd concentration in soils. although Pb, Cu, Zn and Cd have been shown to have anthropogenic origin inputs, however in respect to PCA analysis, the main origins for Lead and Zn may be municipal and industrial operations specially Pb processing factory as well as industrial complexes. At the same time, Cu and Cd stems from farming operations as well as municipal activities. The main municipal input origins for elements Pb, Cu and Cd include all components used in automobile industry, batteries, engines oils, fossil fuels and construction materials (like cement).
Cluster analysis is used to classifying those samples having common and similar characteristics as well as evaluating information obtained from PCA analysis. Cluster analysis gave the same groups. So two majororigins can be identified. First (CI) involves prior interpreted lithogenic elements (Cr, Co, Mn and Fe), while two later clusters (C2, C3) contain anthropogenic elements (Pb, Cu, Zn and Cd). Many researchers believed that Mn, Cr, Ni and Fe are controlled by parent material. In contrast, they attributed any increases of Pb, Cu, Cd and Zn accumulation to anthropogenical operations. Cluster analysis gives the same results as derived from PCA, enabling us to identify two major origins on which heavy metals break out hence, multivariate analysis results confirms the presence of two different heavy metals origins within soils.
Conclusion: The aim of this research was to provide some preliminary information on heavy metals (Pb,Zn,Cd,Cu,Ni,Co,Cr,FeandMn) contamination status in soils in Zanjan province. Metal contamination cannot be assessed by common metal concentration test, hence useful and promising tools were applied to evaluate heavy metals pollution. The highest level of heavy metals pollution and accumulation was related to Cd, Pb and followed by then Cu. Multivariate analysis showed that Fe, Mn, Cr, Co and Ni are controlled by parent materials, while Pb, Cu and Zn originate from anthropogenic sources. In the second class, anthropogenic activity did not seem to significantly affect their accumulation which is strongly supported the lithogenicaly origin of these heavy metals in this study.
A. Afshari; H. Khademi; shamsollah Ayoubi
Abstract
Introduction: Heavy metals are types of elements naturally present in soil or enter into soil as a result of human activities. The most important route of exposure to heavy metals is daily intake of food. Crops grown in contaminated soil (due to mining activities, industrial operations and agriculture) ...
Read More
Introduction: Heavy metals are types of elements naturally present in soil or enter into soil as a result of human activities. The most important route of exposure to heavy metals is daily intake of food. Crops grown in contaminated soil (due to mining activities, industrial operations and agriculture) may contain high concentrations of heavy metals. Also closeness to cities and industrial centers can have a great influence on the accumulation of heavy metals to agricultural products grown in the region. The study aimed to determine the concentration of heavy metals in soil and agricultural products around urban and industrial areas of Zanjan province (North West of Iran) and consumption hazard probability.
Materials and Methods: Soil (75 samples of soil from a depth of 0 to 10 cm) and plant (101 samples) samples, in the summer 2011, were randomly taken from industrial areas as follow: tomatoes (Lycopersicum esculentum M), wheat seed (Triticum vulgare), barley seeds (Hordeum vulgare), alfalfa shoots (Medicago sativa L.), potato tubers (Solanumtuberosum L.), apple fruit, vegetables and fruits such as Dill (Aniethum graveolens L.), leek (Allium porrum L.), Gardencress (Barbara verna L.) and basil (Ocimum basilicum L.). Plant samples were then washed with distilled water, oven dried for48 hours at a temperature of 70 ´C until constant weight was attained and then they digested using 2 M hydrochloric acid (HCl) and nitric acid digestion in 5 M. Concentrations of heavy metals in the soil and crops were determined by atomic absorption spectrometry. DTPA extraction of metals by Lindsay and Norvell (1978) method and sequential extraction method by Tessier et al. (1979) were performed. Statistical analysis was accomplished using the software SPSS 16.0 and the comparison of mean values was done using the Duncan test at the 5% level of significance.
Results and Discussion: The magnitude of variations for total copper was from 11.5 to 352.5 (average 52.4), zinc was from 96.3 to 1353.8 (average 264.8), lead was between 40.0 and 470.0 (average 105.7), nickel ranged from 12.8 to 77.0 (average 46.7) and chromium varied from 10.0 to 49.5 (average 21.7) mg kg-1. DTPA extracted heavy metals for copper varied from 1.50 to 21.23, averaging 4.47, zinc from 0.57 to 76.50 averaging 23.15, lead from 2.43 to 63.38 averaging 16.81 and nickel from 0.28 to 2.32 averaging 1.20 mg kg-1. Chemical changes in the different fractions were as follows: Cu (residual > bounded to organic matter > bounded to Fe-Mn oxides > bounded to carbonate > exchangeable fraction), Zn and Ni (residual > bounded to Fe-Mn oxides > bounded to carbonate > bounded to organic matter > exchangeable fraction,) and Pb (residual > bounded to Fe-Mn oxides > bounded to organic matter > bounded to carbonate > exchangeable fraction). The concentration of heavy metals in plant parts were high with respect to studied location. The highest amounts of Zn (Gardencress), Pb (Dill), Cu (Leek), Ni (Basil) and Cr (Basil), respectively were found to be 150.25, 41.25, 23.13, 6.46 and 3.47 mg kg-1 and the minimum amounts of the metals studied were found in fruits, wheat and barley grains. The total amount of metals in plants were as follow (Zn >> Pb > Cu > Ni > Cr). Bioaccumulation factor (BAF) of metals in plants were as Zn=Cu > Pb >> Cr > Ni. Hazard probability (HQ) in cancerous diseases for each element (except Pb) in both children and adults was less than unit. HQ content of Pb was much higher than the unit and for children and adults 9.07 and 6.94, respectively showing high contribution of Pb contamination of crops that threatens the consumer health in that location. The total amount of risk (THQ) in children was higher than that in adults.
Conclusions: The results obtained in this study indicate that an urgent attention is required for consumer products related to public health, especially vegetables grown in the studied regions. Toxic effects of heavy metals have many deleterious effects which are more pronounced over time. With conventional monitoring of food quality produced in farms and presented in markets, excessive accumulation of heavy metals entering in to the human food chain can be prevented. Also, we can change the risk potential of heavy metals in the region by growing vegetables which accumulate heavy metals.
Keywords: Agriculture products, Biological risk, Heavy metals, Soil, Zanjan province
M. Valaee; Sh. Ayoubi; H. Khademi; F. Khormali
Abstract
Introduction: Soil moisture regime refers to the presence or absence either of ground water or of water held at a tension of less than 1500 kPa in the soil or in specific horizons during periods of the year. It is the most important factor in soil formation, soil evolution and fertility affecting on ...
Read More
Introduction: Soil moisture regime refers to the presence or absence either of ground water or of water held at a tension of less than 1500 kPa in the soil or in specific horizons during periods of the year. It is the most important factor in soil formation, soil evolution and fertility affecting on crop production and management. Also, it widely is practical in soil classification and soil mapping. The soil moisture regime depends on the soil properties, climatic and weather conditions, characteristics of natural plant formations and, in cultivated soils, is affected by the characteristics of crops grown, as well as the cultivation practices. Determination of soil moisture regime within a landscape scale requires high information and data about moisture balance of soil profile during some years according to Soil Survey Manual (2010). This approach is very expensive, labor, time and cost consuming. Therefore, achievement to an alternative approach is seems essential to overcome these problems. The main hypothesis of this study was to use capability of magnetic susceptibility as a cheap and rapid technique could determine the soil moisture regimes. Magnetic properties of soils reflect the impacts of soil mineral composition, particularly the quantity of ferrimagnetic minerals such as maghemite and magnetite. Magnetic susceptibility measurements can serve a variety of applications including the changes in soil forming processes and ecological services, understanding of lithological effects, insight of sedimentation processes and soil drainage.
Materials and Methods: This study was conducted in an area located between 36°46َ 10˝ and 37° 2’ 28˝ N latitudes, and 54° 29’ 31˝ and 55° 12’ 47˝ E longitudes in Golestan province, northern Iran. In the study region mean annual temperature varies from 12.4 to 19.4 °C. The average annual rainfall and evapotranspiration varies from 230 mm and 2335 mm in Inchebrun district (Aridic regime), to 732 mm and 846 mm in Touskstan uplands (Udic regime), respectively. this study was conducted in four soil moisture regimes (Aridic, Xeric, Udic and Aquic), for exploring the relationships between soil properties and magnetic measures. In each regimes, 25 soil profiles were drug, described and soil samples were collected from each of soil horizons. Soil samples were air-dried and sieved using a 2 mm sieve. The dithionite-citrate bicarbonate (DCB) method was used to measure Fed and acid ammonium oxalate for Feo. In this study, a set of environmental magnetic parameters including magnetic susceptibility at low frequency (χlf), saturation isothermal remnant magnetization (SIRM), isothermal remnant magnetization (IRM100 mT) were measured. Magnetic susceptibility (χ) was measured at low frequency (0.47 kHz; χlf) and high frequency (4.7 kHz; χhf) using a Bartington MS2 dual frequency sensor using approximately 20 g of soil held in a four-dram clear plastic vial (2.3 cm diameter). Frequency dependent susceptibility (χfd) was determined by the difference between the high and low frequency measurements as a percentage of χ at low frequency. IRM was measured at the field of 100 mT generated in a Molspin pulse magnetizer (IRM100mT) and at the back field of 100mT (IRM−100mT). The IRM acquired in the maximum field of 1000 mT was measured and defined as the saturation isothermal remnant magnetization (SIRM) of the soil sample.
Results and Discussion: The results showed that moisture regime induced significant differences for soil physical and chemical properties. Diversities in genetic soil horizons and soil development degree have been increased from Aridic to Udic soil moisture regime. The results also indicated that selected properties including magnetic measures and physical and chemical properties were significantly different in four soil moisture regimes. With increasing rainfall and reducing temperature from aridic to udic soil moisture regime, soil organic matter was increased. Otherwise, in arid environment Gypsic, Calcic and Salic horizons were observed in the near of soil surface. Fed and Fed-Feo were the highest in udic and the lowest in udic soil moisture regime, respectively. Moreover, higher soil development because of climate effect leaded to higher amount of pedogenic ferromagnetic minerals, as well as the highest were observed in the Udic regime. Otherwise, in Aquic moisture regime, the lowest value of magnetic susceptibility was obtained because of dissolution of ferromagnetic minerals (magnetite and maghemite) under supersaturating condition. In overall, close relationships were observed between soil physical and chemical properties and magnetic measures in various soil moisture regimes.
Hadis Hatami; Ali reza Karimi; A. Fotovat; H. Khademi
Abstract
Aluminosilicates such as K-feldspar and micaceous minerals are the main source of potassium in soils. The objectives of this study were to investigate the release of K from micaceous minerals (biotite, phlogopite, muscovite) and K-feldspars (Zanjan and Yazd) using sequential extraction by 0.05 M BaCl2 ...
Read More
Aluminosilicates such as K-feldspar and micaceous minerals are the main source of potassium in soils. The objectives of this study were to investigate the release of K from micaceous minerals (biotite, phlogopite, muscovite) and K-feldspars (Zanjan and Yazd) using sequential extraction by 0.05 M BaCl2 and determine the effect of mineral grain size and application of kinetic models to describe K release. For this purpose, sequential extraction with BaCl2 was conducted on two sizes of 50-100 and less than 50 micron for the periods of 2-600 hours. The amount of K released into the solution was measured by flame photometer. The results indicated that after 13 times of extraction, in the both sizes, biotite and muscovite had the highest and lowest values of K release, respectively. Meanwhile, the released K increased by decreasing the mineral size. The kinetics of K release from minerals consisted of two phases, the first phase was relatively rapid and then continued with a slow rate to end of the experiment. Regarding the high determination coefficient (R2) and low standard error of the estimate (SE), parabulic diffusion and exponential function equations could reasonably describe the K release kinetics. Therefore, it may be concluded that the release of K is controlled by diffusion process from the surface of the study minerals.
B. Azimzadeh; H. Khademi
Abstract
One of the main problems in soil pollution evaluation is the lack of regional standards. The objectives of this study were (i) to estimate the background concentration of some heavy metals for environmental assessment and, (ii) to locate heavy metal polluted soils in part of central Mazandaran Province. ...
Read More
One of the main problems in soil pollution evaluation is the lack of regional standards. The objectives of this study were (i) to estimate the background concentration of some heavy metals for environmental assessment and, (ii) to locate heavy metal polluted soils in part of central Mazandaran Province. The study region with 5500 km 2 area is important in terms of agricultural activities and population density. Using nested-systematic method, 256 composite soil samples were taken from the depth of 0-10 cm, including 148, 60, and 48 soil samples in agricultural land, urban area, and natural lands (forest and rangeland), respectively. After preparation and extraction of soil samples with 5 N nitric acid, the total concentration of Cu, Zn, Ni, Pb, and Cd was measured by an atomic absorption spectrometer. Natural background concentration (NBC) of Cu, Zn, Ni, Pb, and Cd was estimated to be 28.3, 40.2, 45.7, 34.2, and 0.23 mg kg-1, respectively. Interpolated distribution map of contamination factors (CF) and pollution load index (PLI) of heavy metals were prepared using NBC. The overlap of CF and PLI maps with geology and land use maps was indicated that the concentration of Pb, Zn, and Cu has been affected by human activities such as traffic, whereas Cd and Ni contents are controlled by natural factors such as parent material, and agricultural activities, mostly. Based on the classes of CF, most samples are moderately contaminated with heavy metals.
salman naimi marandi; shamsollah Ayoubi; H. Khademi
Abstract
Soil pollution by heavy metals from the manufacturing process due to metal smelting plants closely related to human health is very important. Given the importance of the province to industrial and agricultural activities, this study was conducted to explore the vertical and horizontal variability of ...
Read More
Soil pollution by heavy metals from the manufacturing process due to metal smelting plants closely related to human health is very important. Given the importance of the province to industrial and agricultural activities, this study was conducted to explore the vertical and horizontal variability of lead and nickcl metals in contaminated soils around the Zobahan melting factory, in nearby of Isfahan city. For this purpose, 202 profiles were dug and described in the green landscapes of Zobahan industrial site by a manner of gird sampling method. Five hundred soil samples were taken from depths of 0–30, 60–90, and 120–150 cm. Conccntration of total lead (Pb) and nickel (Ni) were measured in the soil samples. To explore the vertical distribution of selected metals, the mean values of Ni and Pb were compared statistically. The horizontal variability of selected metals was evaluated by variography analysis and the spatial distributions of them were constructed by kriging method. The overall results of study showed that Pb content in surface horizons is controlled by industrial activity, otherwise the concentration of Ni mainly attributed to parent material.
M. Mohseni Sajadi; M. Afyuni; H. Khademi; Seyed Asadallah Mohseni Movahed; Sh. Ayoubi
Abstract
Abstract
Fluoride (F-) is an essential element for human and some animals. The fluoride concentration in irrigation water is an important index for water quality. The objective of the present study was to determine spatial variability of fluoride in groundwater and soils of some areas in Arak plain. ...
Read More
Abstract
Fluoride (F-) is an essential element for human and some animals. The fluoride concentration in irrigation water is an important index for water quality. The objective of the present study was to determine spatial variability of fluoride in groundwater and soils of some areas in Arak plain. Therefore, during two seasons, autumn (2007) and the end of spring (2008), 87 and 92 water samples were collected from the wells, in the study area, respectively. Furthermore thirty soil samples were taken from the same positions. Fluoride concentrations in groundwater and soil samples around Arak city was measured by Ion Selective Electrode (ISE) method. The results show that the average fluoride of water samples during two seasons ranged from 0.3 to 0.06 mg/L which is below the standard level (1.5). These values were suitable for irrigation. Generally, spatial distribution in groundwater and isopiezometry maps indicated that fluoride increased where groundwater flow lines were centralized. Besides, fluoride concentration has increased in the rural zones and discharge areas. Average concentration of fluoride in agricultural and industrial areas were 1.5 and 7.5 mg/Kg respectively. Maximum concentration of fluoride belonged to industrial areas with 26.5 mg/Kg showing significant difference in 1 % scale in comparison with agricultural zone. There was negative correlation between fluoride with lime values and positive correlation with pH.
Keywords: Fluoride, Spatial variability, Groundwater, Soil, Arak plain
A. Hadinezhad; H. Khademi; Sh. Ayoubi; H. Lotfi Parsa
Abstract
Abstract
Heated micaceous minerals under different commercial brand names (including vermiculite) are used as culture medium in greenhouses. Heating minerals affects the release of elements, such as potassium, by changing their structure. The present study, investigates the ability of alfalfa, as one ...
Read More
Abstract
Heated micaceous minerals under different commercial brand names (including vermiculite) are used as culture medium in greenhouses. Heating minerals affects the release of elements, such as potassium, by changing their structure. The present study, investigates the ability of alfalfa, as one of the most important fodder around the world, to take up the non-exchangeable and structural potassium from heated micaceous minerals. The simultaneous effects of heat treatments and rhizospheric conditions on potassium release from two heated micaceous minerals including muscovite, as a di-ochtahedral mica, and phlogipite, as a tri-ochtahedral one, were studied in a pot experiment. The experiment was carried out as a completely randomized design with factorial combinations and three replications. Minerals were heated at 100 to 900 0C for 5 hours and mixed with quartz sand to fill the pots as the culture medium. Pots were irrigated with two different nutrient solutions (+K or -K) and distilled water during a period of five months. At the end of experiment, dry matter of shoot and root samples was measured separately. The K uptake by plant was then measured by flame photometer following the dry ash extraction. Results revealed different responses of micaceous minerals to heat treatments. In K-free treatments, the plant K uptake was significantly influenced by culture media. The most plant K available was released at 100 and 200 0C for muscovite and phlogopite treated plants, respectively. The structural changes causing a considerable decrease in potassium release, also took place at 700 0C for phlogopite and 500 to 700 0C for muscovite.
Keywords: Heat treatments, Potassium release, Muscovite, Phlogopite, Alfalfa
A. Jafari; Sh. Ayoubi; H. Khademi
Abstract
چکیده
شناسایی رقومی خاک ها بهعنوان ابزاری برای ایجاد اطلاعات مکانی خاک، راه حل هایی برای نیاز رو به افزایش نقشه های خاک با تفکیک مکانی بالا را تأمین می کند. بنابراین، ...
Read More
چکیده
شناسایی رقومی خاک ها بهعنوان ابزاری برای ایجاد اطلاعات مکانی خاک، راه حل هایی برای نیاز رو به افزایش نقشه های خاک با تفکیک مکانی بالا را تأمین می کند. بنابراین، باید روش های جدید بهمنظور بهدست آوردن اطلاعات مکانی خاک با تفکیک مکانی بالا توسعه پیدا کند. به همین منظور مطالعه ای جهت پیش بینی کلاس های خاک با استفاده از مدل های رگرسیونی در منطقه زرند کرمان طراحی گردید. در این مطالعه، مدل های رگرسیونی شامل رگرسیون لاجیستیک چندجمله ای و رگرسیون درختی توسعه یافته چندکلاسه برای پیش بینی گروه بزرگ خاک به کمک داده های سنجش از دور، پارامترهای سرزمین و نقشه ژئومرفولوژی استفاده گردید. کیفیت پیش بینی مدل ها با شاخص های حاصل از آرایه خطا بررسی گردید. نتایج نشان داد در پیش بینی همه گروه های بزرگ خاک، سطوح ژئومرفیک بهعنوان یک پیش بینی کننده مؤثر محسوب می شود. بعد از سطوح ژئومرفیک، پارامترهای سرزمین و شاخص های سنجش از دور در پیش بینی وارد شدند. در هر دو مدل خلوص نقشه برای همه گروه های بزرگ خاک در موقعیت های اعتبارسنجی و واسنجی بیشتر از 6/0 بود. نتایج نشان داد عملکرد پیش بینی برای گروه های بزرگ هاپلوجیپسید و هاپلوسالید بهتر از گروه های بزرگ کلسی جیپسید و هاپلوکمبید بود. در بین گروه های بزرگ خاک، مقادیر بالای دقت کاربر و قابلیت اطمینان تولیدکننده برای گروه بزرگ هاپلوسالید بهدست آمد. خاک های با قابلیت اطمینان بهتر خاک هایی هستند که به شدت تحت تأثیر مشخصات توپوگرافی و ژئومرفولوژی قرار گرفتند (گروه های بزرگ هاپلوسالید، تری سامنت و هاپلوجیپسید) و خاک های با قابلیت اطمینان و دقت پیش بینی کمتر خاک هایی هستند که به سختی تحت تأثیر مشخصات توپوگرافی و ژئومرفولوژی (گروه های بزرگ هاپلوکمبید و کلسی جیپسید) قرار گرفتند.
واژه های کلیدی: نقشه برداری رقومی خاک، رگرسیون لاجیستیک چندجمله ای، رگرسیون درختی توسعه یافته
F. Noruzi Fard; M.H. Salehi; H. Khademi; A.R. Davoudian Dehkordi
Abstract
چکیده
ماده مادری از مهمترین فاکتورهای خاک سازی در مناطق خشک و نیمهخشک محسوب میگردد. هدف از این مطالعه، بررسی تأثیر مواد مادری آذرین، دگرگونی و رسوبی بـر روی برخی ...
Read More
چکیده
ماده مادری از مهمترین فاکتورهای خاک سازی در مناطق خشک و نیمهخشک محسوب میگردد. هدف از این مطالعه، بررسی تأثیر مواد مادری آذرین، دگرگونی و رسوبی بـر روی برخی از ویژگیهای فیزیکی، شیمیـایی، کانیشناسی و ردهبندی خاکها در شمال استان چهارمحال و بختیاری است. پس از انتخاب هفت نوع سنگ مادری شامل گرانیت، بازالت، سنگ آهک، شیل، میکـاشیست، گنیس و آمفیبـولیت، بر روی هر یک از آنها سه خاکرخ، حفر و تشریح گردید و یک خاکرخ از هر سنگ بستر به عنوان خاکرخ شاهد برای تجزیههای فیزیکی، شیمیایی و کانیشناسی رس موجود در سنگ بستر و افقهای خاک انتخاب گردید. نتایج نشان داد ویژگیهای فیزیکوشیمیایی خاک، کانیشناسی و ردهبندی خاکها به میزان قابل ملاحظهای توسط مواد مادری، کنترل میشود. اغلب خاکها تنها دارای دو افق A و BC بودند و در راسته انتیسولز طبقهبندی گردیدند و تنها خاکهای موجود بر روی شیل و گنیس، به دلیل وجود افق مشخصه B، در راسته اینسپتیسولز ردهبندی شدند. تفاوت در ردهبندی خاکهای موجود در یک راسته نیز از سطح زیر گروه یا فامیل خاک مشاهده شد که نشاندهنده لزوم ردهبندی خاک در سطوح پایین برای اهداف مدیریتی است. نتایج کانیشناسی بخش رس نشان داد در همه خاکها و ماده مادری آنها کانیهای کلریت، کائولینیت، کوارتز و میکا (بجز افق سطحی خاک تشکیل شده بر روی سنگ بازالت و نمونه سنگ شیل) وجود دارد و منشأ آنها در خاکها توارثی است. منشأ اسمکتیت در خاکهای حاصل از گرانیت و بازالت، پدوژنیکی و در خاک حاصل از سنگ آهک، توارثی تشخیص داده شد در حالی که در خاک به وجود آمده از سنگ گنیس، دو منشاء توارثی و پدوژنیکی بهنظر میرسد. وجود ورمیکولیت در خاک به وجود آمده از آمفیبولیت ناشی از به ارث رسیدن از ماده مادری و در خاکهای تشکیل شده بر روی میکاشیست و شیل بهدلیل تشکیل در محیط خاک میباشد.
واژه های کلیدی: ماده مادری، ویژگیهای فیزیکی و شیمیایی خاک، کانی شناسی رس، رده بندی
F. Khayamim; H. Khademi; M.H. Salehi
Abstract
Abstract
The association between Neotyphodium spp. endophytes and cool-season grasses, particularly tall fescue (Festuca arundinacea, Schreb), represents a widespread type of mutualism in nature. Numerous researches were performed about positive effect of symbiosis on plant resistance to different stresses ...
Read More
Abstract
The association between Neotyphodium spp. endophytes and cool-season grasses, particularly tall fescue (Festuca arundinacea, Schreb), represents a widespread type of mutualism in nature. Numerous researches were performed about positive effect of symbiosis on plant resistance to different stresses but the role of symbiosis on nutrients uptake particularly potassium uptake and K-bearing mineral transformation is not well recognized. The objective of this research was to investigate the effect of endophyte-tall fescue symbiosis on the transformation of clay-sized micaceous minerals. A pot experiment under green house conditions was carried out in a completely randomized design with factorial combinations and three replicates. The culture medium was a mixture of quartz sand (as filling material) and phlogopite or muscovite. Tall fescue 75B genotype either infected by the natural endophyte Neotyphodium or non-infected isoline was chosen for cultivation. Pots were irrigated with distilled water and complete or K-free nutrient solutions during a period of 140 days. At the end of the experiment, shoots and roots were harvested. Plant samples were prepared with dry ashing method and their K concentration was determined with flame photometer. The clay-sized particles in each pot were mineralogically studied using an X-ray diffractometer. The results showed the vermiculitization of phlogopite under both nutrient solutions conditions, but with a much higher rate in pots treated with K-free nutrient solution. In addition to vermiculite, smectite and chlorite were also detected as newly formed minerals in phlogopite amended pots. Also, a very weak vermiculitization was observed in muscovite treated media. Under the K-free nutrient solution and in phlogopite amended treatments, the 1.4/1.0 nm peak ratio for endophyte infected plants was 4 times greater than that under non-infected plants. Such a significant difference in phlogopite vermiculitization is attributed to endophyte symbiosis and its positive effects on the type and quantity of tall fescue roots secretions. A significant decrease in pH values under the rhizosphere of infected plants further confirmed this hypothesis.
Keywords: Endophyte fungi, Phlogopite, Muscovite, Vermiculite, Mineral transformation
M. Taghipour; H. Khademi; Sh. Ayoubi
Abstract
Abstract
Accumulation of heavy metals in soils has become a serious environmental problem in many parts of the world. No information is currently available on the distribution pattern of heavy metals concentration in soils of Hamadan province. The objective of this research was to determine the spatial ...
Read More
Abstract
Accumulation of heavy metals in soils has become a serious environmental problem in many parts of the world. No information is currently available on the distribution pattern of heavy metals concentration in soils of Hamadan province. The objective of this research was to determine the spatial distribution of Pb and Zn and its relationship with land use and parent materials of a selected area surrounding the city of Hamadan. A total of 263 composite surface soil samples (0-10 Cm) were taken from an area of about 1600 km2. The location of each sampling site was recorded by using a GPS and its land use type (residential, uncultivated, agricultural land and dryland wheat) was also determined. In addition from six major types of bedrock in the Hamadan province were also sampled with 3 replicates. The total and plant available Zn and Pb in soil samples and the total concentration of these elements in parent rocks were measured by atomic absorption spectrophotometer after extraction. Selected soil properties including pH, electrical conductivity, organic matter, cation exchange capacity and soil texture were also determined. The spatial variability of variables was examined by variography and kriging analysis. The mean concentration of total and available Zn were 71.4 and 2.5 mg Kg-1 and those for Pb were 24 and 2.5 mg Kg-1, respectively. The results of geostatistical analysis showed that spherical model was the best model for describing the spatial variability of Pb and Zn. The range of influence was estimated 9750 m for Pb and 11550 m for Zn. It seems that the major factor controlling the high concentration of total Pb and Zn in the area is land use type. Analysis of parent rock samples indicated that shale as the major parent rock occurring in the southeast and west part of the study area contains a high quantity of Zn (96.2 mg Kg-1). Therefore, it appears that Zn has entered the soils in the study area through the weathering of parent materials. In other words, the content of Zn in the soils studied seems to be mainly controlled by soil parent material and land use. A significant correlation was found between organic matter and the concentration of Pb.(r2= 0.35) and Zn (r2= 0.33).
Keywords: Spatial variability, Heavy metals, Parent materials, Variogram, Kriging, Hamadan
A.R. Pilevar Shahri; Sh. Ayoubi; H. Khademi
Abstract
Abstract
Spatial prediction of soil organic carbon is a crucial proxy to manage and conserve natural resources, monitoring CO2 and preventing soil erosion strategies within the landscape, regional, and global scale. The objectives of this study was to evaluate capability of artificial neural network ...
Read More
Abstract
Spatial prediction of soil organic carbon is a crucial proxy to manage and conserve natural resources, monitoring CO2 and preventing soil erosion strategies within the landscape, regional, and global scale. The objectives of this study was to evaluate capability of artificial neural network and multivariate linear regression models in order to predict soil organic carbon using terrain attributes. A study area of 24 km2 in hilly regions of Zargham Ababd in south of Semirom under natural rangeland uses, was selected and then 125 soil samples (0-10 cm depth) were collected. Soil organic carbon was measured for the collected soil samples. Topographic attributes were calculated by a digital elevation model with 10 m spacing. Finally, multiple linear regression (MLR) analysis and ANN models were developed for soil organic carbon estimation in the study area and then the developed modeless were validated by additional samples (25 points). The results showed that the MLR and ANN models explained 60 and 89 % of the total variability of SOC, respectively, in the study area using terrain attributes. Sensitivity analysis based upon the ANN models, revealed that the profile curvature, stream power index, slope, sediment transport index, wetness index, plan curvature and aspect were identified as the important topographic attributes influencing the SOC distribution within the selected hillslope. The overall results indicated that topographic attributes and hydrological process control a significant variability of SOC. Prediction of the statistical studied models in the study area resulted in mean error and root mean square error values of 0.25, 0.3 in MLR equation and 0.006, 0.027 in ANN, respectively. Therefore, the ANN model could provide superior predictive performance when compared with developed MLR model.
Keywords: Soil organic carbon, Terrain attributes, Linear regression, Artificial neural network
F. Khayamim; H. Khademi; A. Khoshgoftar manesh; Sh. Ayoubi
Abstract
Abstract
Mineral weathering is a major source of most essential nutrients including potassium. It is well known that potassium plays an important role in improving the quality of agricultural products and micaceous minerals, as the major source of potassium, are abundant in Iranian soils. No information ...
Read More
Abstract
Mineral weathering is a major source of most essential nutrients including potassium. It is well known that potassium plays an important role in improving the quality of agricultural products and micaceous minerals, as the major source of potassium, are abundant in Iranian soils. No information is available on the role of micaceous minerals in supplying K to barley as the second major crop in Iran. The objective of this research was to demonstrate the ability of barley (Hordeum vulgare L.) to take up structural potassium from muscovite and phlogopite. The experiment was carried out in a completely randomized design with factorial combinations and three replicates. Culture medium was a mixture of quartz sand (as filling material) and K-bearing minerals including muscovite or phlogopite. Pots were irrigated with different nutrient solutions (+K and -K) during a period of four months. Barley Govhar cultivar was used which is widely cultivated in the Isfahan province. At the end of experiment, shoots and roots were separated and plant samples were prepared with dry ashing method and their K content was determined with flame photometer. In K-free treatments, total plant K uptake was significantly higher in phlogopite treated medium as compared to muscovite. No significant difference was found between control and muscovite amended treatment under K-free solution. In pots amended with phlogopite, K concentration was in sufficient limit, even under K-free nutrient solution. This indicates the importance of the type of micaceous minerals in plant K availability, particularly in soils where minerals structural K is the only source of K supply.
Key words: Muscovite, Phlogopite, Barley, Rhizospheric effections, Potassium release
S. Noruzi; H. Khademi
Abstract
Abstract
Low molecular weight carboxylic acids (LMW) play an important role in improving the bioavailability of soil nutrients. Nonexchangeable soil K, trapped between the interlayers of clay minerals, is an important source of K for plants in many soils. The objectives of this study were to determine ...
Read More
Abstract
Low molecular weight carboxylic acids (LMW) play an important role in improving the bioavailability of soil nutrients. Nonexchangeable soil K, trapped between the interlayers of clay minerals, is an important source of K for plants in many soils. The objectives of this study were to determine the effect of selected LMW organic acids on the release of K from micaceous minerals and to investigate the resulting mineralogical changes. A laboratory dissolution study was carried out using a completely randomized design with three replicates. Muscovite and phlogopite (< 60 μm size) were reacted with 0, 500, 2000 and 4000 μM solutions of oxalic, citric and malic acids for a period of 5 hours to 120 days. The amount of K released to the solution was determined with flame photometer. The rate of K release varied with the type of organic acids and also the kind of mica. Citric acid solution with a concentration of 4000 μM was able to release more K from minerals. The higher the concentration of organic acid, the higher the amount of K released. The amount of K released from minerals was in the order of phlogopite>muscovite. The kinetics of non-exchangeable K release from minerals consisted of two phases, the first phase was relatively rapid and then it had a constant rate untile the end of experiment. Strongly coordinating LMW carboxylic acids enhance the mineral dissolution and weathering reactions through the detachment of surface complexes into solution. There was not any XRD detectable changes in minerals reacted with organic acids up to 4 months.
Keywords: Potassium release, Organic acids, Muscovite, Phlogopite, Mineralogical changes