Environmental Sciences
Year:2017 | Volume:15 | Issue:2 |Papers Count:13

Introduction: As the largest international wetland in Iran, Shadegan Wetland is one of the most important and valuable wetlands in the country and, even, the world. The widespread nature of the wetland, its natural character, high abundance of plant species, animals and its habitats has brought tremendous value to the wetland. In recent years, this valuable wetland has been exposed to drying up and destruction due to natural and human factors. The livelihood of rural households in the area is in all respects indebted to Shadegan Wetland: The death of the wetland will be accompanied by the death of their livelihood. One of the ways to reduce the vulnerability of marginalized people in Shadegan Wetland is to emphasize on their adaptation behaviors. In this regards, the present study aimed to explore beneficiaries Conservation Behavior against drought effects in Shadegan Wetlands based on vulnerability theory.Materials and methods: The present study in terms of its nature and objectives is practical, in terms of data collection, is a descriptive survey and, in terms of analyzing the data, is a correlation study. The total population were the rural operators living in the central part of the town and Khnafereh village in Shadegan City, Khuzestan Province (Iran). They consisted of eight villages with 2319 household operators (N=2319). A random-quota method was used as sampling (n=124) and data were gathered via the use of a research-based questionnaire. The reliability of the questionnaire was confirmed by calculating Cronbach’s alpha coefficient as greater than 0.76. The validity of the questionnaire was confirmed by a panel of experts, and the data were analyzed using SPSSv20 and AMOSv20.Results and discussion: According to the results, 47.6 percent of the beneficiaries of the wetland show an irresponsible behaviour towards the vulnerability of natural and human hazard and 52.4 percent of them haveresponsible behaviour. Results of the study showed that sensitivity has a significantly positive effect onvulnerability (b=0.377) and conservation behaviour (b=0.208). Exposure has a significantly positive effect on vulnerability (b=0.492) and conservation behaviour (b=0.3). Also, the results revealed that exposure, sensitivity and adaptive capacity predict a 41% variation in vulnerability. Exposure, sensitivity and vulnerability predict a 20 % variation in conservation behaviour.Conclusion: Thus, it can be concluded that exposure of the beneficiaries to the drought conditions of Shadegan Wetland and their sensitivity to drought have resulted in vulnerability and adaptation behaviour among them. Hence, exposure to wetland droughts can have both direct and indirect effects on their lives. For example, changing product performance in response to drought can be one of the direct effects of this phenomenon. Also, an increase in unemployment resulting from the drying of the wetland due to the reduction of Karun and Jarahi rivers is one of its indirect effects. Therefore, the residents of the area are going to respond to these and this will lead to the adaptation behaviour of the beneficiaries.

Introduction: Chickpea contains a high level of protein and plays very important role in the food security cycle in the worldwide, especially in the developing countries such as Iran which is one of the most important Asian countries in terms of chickpea production. Indeed, Iranian chickpea is planted in 33 countries and its area of cultivation in Iran is approximately 650000 hectare (Ahmed Khan, 2009). Low grain yield is the most basic problem of chickpea in Iran and plant breeding is a economic and permanent solution for solving this problem. Genetic diversity, heritability and intensive selection are three effective factors for responding to selection of traits. As a consequence, multivariate statistical methods are conventional and suitable for identifying genetic diversity in plant breeding programmes; principal component analysis, factor analysis, cluster analysis and discriminate function are the most important multivariate methods generally used for different plants. Many researchers have used multivariate statistical methods in rice (Gholipour and Mohammad-Salehi, 2003), potato (Rabie et al., 2008), wheat (Zaki Zadeh et al., 2010), chickpea (Jeena and Arora, 2002), and Identifying the most effective genotypes and traits in chickpea and assessing the genotype diversity were the main objectives of the current research.Materials and methods: In order to assess genetic diversity and identify the most important and effective traits of grain yield in 19 chickpea genotypes, the current experiment was conducted based on a randomized complete block design with three replications under well water conditions. The experiment was carried out in the Bu-Ali Sina University research field growing season and laboratory of Payame Noor University. The traits of chlorophyll index, plant height, branch number per plant, pod number per plant, seed number per plant, seed number per pod, 100-kernel weight, economic yield per unit area, biological yield per unit area and harvest index were measured. After trait measurement, principal component analysis (PCA), factor analysis (FA), cluster analysis (CA) and discriminate function analysis (DFA) were carried out in order to reach the aims of the research.Results and discussion: The results showed that the maximum coefficient of variation belonged to the traits of pod number per plant and harvest index, while the trait of 100-kernel weight had the minimum coefficient of variation. The results of principal component analysis showed that the three first components explained 68.9 percent of the total variance of the traits. The first and second components were known as the “grain yield” and “harvest index” components, respectively. In addition, factor analysis identified the three factors of “grain yield, “harvest index” and “plant vigour”. Cluster analysis based on the WARD method grouped the genotypes into four clusters. Meanwhile, discriminate function analysis confirmed the cluster analysis groups. The results showed a high genetic diversity among the lines. Lines number 12 and 18 were recognized as generally the best and the worst genotypes. In addition, the traits of pod number per plant, 100-kernel weight and harvest index had maximum effect on grain yield, while the trait of branch number per plant had a negative effect on grain yield in the current research.Conclusion: According to the results obtained in the research, multivariate statistical methods are suitable and efficient methods for data reduction and indirect selection of grain yield that could successfully separate the efficient genotypes and the traits. The main objective was to assess the genetic diversity of 19 chickpea lines for their application in the new plant breeding programmes. According to the total results, the traits of pod number per plant were recognized as the most suitable traits for indirect grain yield selection. Line number 12, as a suitable line, had a maximum amount of the traits of pod number per plant, 100-kernel weight and harvest, while line number 18 (an unsuitable line) included the maximum amount of the trait of branch number per plant.

Introduction: The amount of nitrogen compounds released into the atmosphere has increased, and is higher in industrial areas due to the increasing usage of fossil fuels and chemical fertilizers (Gruber and Galloway, 2008). Nitrogen deposition is one the consequences of increasing atmospheric nitrogen compounds. Nitrogen deposition refers to a process that nitrogen compounds in the atmosphere deposit on a solid surface (Cornell et al., 2003). Due to the lack of information about the effects of nitrogen deposition on forest soil properties, the aim of this study was to investigate the effects of simulated nitrogen deposition on soil chemical properties in a maple plantation located at the educational and research forest of Faculty of Natural Resources (Sari).Materials and methods: Twelve plots of 20 m × 10 m were established in the study plantation stand. Four nitrogen treatments were considered including zero (control), 50 (low), 100 (medium) and 150 (high) kg N ha -1 year -1. Nitrogen in the form of NH4NO3 solution was manually sprayed onto the plots monthly during one year. Three soil samples were taken seasonally at a depth of 0-10 cm in each plot using a coring method and were transported to the laboratory (Xingren et al., 2017). In the laboratory, the physical properties including water content and soil texture were measured by a weighing and hydrometer method, respectively. Chemical properties of soil including pH and EC were measured by potentiometric and electrical conductivity methods, respectively (Soil to water ratio 1: 2.5). Soil organic carbon, total nitrogen, phosphorus and potassium were measured using the Walkley and Black method, Kjeltec System Instrument, Olsen P extracting solution and extracted using ammonium acetate, respectively.Results and discussion: The results showed that the nitrogen deposition had significantly decreased the pH and EC. At the end of the study period, the amount of nitrogen in medium (0.47% ± 0.010) and high (0.59%±0.013) treatments was significantly higher than the control (0.36% ± 0.006). The amount of phosphorus in medium (15.95 ± 0.39 mg kg-1) and high (14.95 ± 0.43 mgkg-1) treatments was significantly lower than the control (24.97 ± 1.05 mgkg-1). In addition, nitrogen deposition had caused a significant reduction in soil potassium. The amounts of ammonium (low: 6.04, medium: 7.23 and high: 8.53) and nitrate (low: 7.21, medium: 9.95 and high: 20.51) were significantly higher than in the control treatment (ammonium: 4.93 nitrate: 5.06). The reason for reduced soil pH and EC can be the leaching of base cations followed by leaching of nitrate and an increased ammonium concentration in the soil. The reason for increased nitrate can be its addition as well as the production of nitrate in the presence of ammonium. In general, results showed that the nitrogen deposition treatments had destructive effects on soil chemical properties that decreased pH and EC, potassium and phosphorus and increased the total nitrogen, organic Carbon, ammonium and nitrate in the soil.Conclusion: Increased nitrogen at the early stages may be partly responsible for tree growth but, with the passage of time and the saturation of nitrogen in the soil and the occurrence of nitrate leaching as well as loss of soil fertility, conditions for the growth of plants would become unsuitable. Due to a lack of data on the effects of nitrogen deposition on soil properties, extensive studies about its effects on the soil chemical and biological properties, such as soil microbial and enzyme activities as well as soil respiration, is suggested.

Introduction: Land Surface Temperature (LST), a significant variable of micro climate and radiation transfer within the atmosphere, is one of the most important criteria in zonal and regional planning because it is a major factor in controlling the Earth’s biological, chemical and physical processes. Natural and man-made activities, especially land use and land cover, by changing the physical and biological conditions of a region are an important parameter in the amount of land surface temperature.Material and methods: In this study, the relationship between land surface temperature and vegetation cover associated with land use and the land cover patterns of Dena County in 2016 were investigated using a Single Window algorithm and Landsat-8 data. The split-window algorithm is a dynamic mathematical tool which estimates land surface temperature (LST) using ground information, brightness temperature of thermal bands of the TIRS sensor, the land surface emissivity (LSE) factor and fractional vegetation cover (FVC) obtained from a multiband OLI sensor.Results and discussion: Based on classification of images of the Landsat-8OLI sensor in 2016 with an accuracy of about 80% and the kappa coefficient 0.90, rangeland and residential areas with 50.67 and 0.3 percent, respectively, were allocated the highest and the lowest areas of Dena county. The mean of land surface temperature in Dena County is about 32 ° C and the mean of the land cover index is about 0.14. In analyzingthe relationship between LST and the vegetation index (NDVI) in Dena County and in each category of land use and land cover, results showed a different trend so that there is a positive and significant relationship between NDVI and LST in the whole of Dena County and rangeland in the event that there is no significant relationship in other land uses such as forest, farm and garden and residential area.Conclusion: Various factors affect the type and shape of the relationship between NDVI and LST such as land use and land cover, vegetation cover, season, time of day, type of ecosystem, latitude and factors in triggering the growth of vegetation such as water and solar energy. The main cause of the ineffectiveness of vegetation cover in reducing the land surface temperature of Dena County is the lack of a sufficient amount of vegetation cover. However, the determining factor of temperature in Dena County is not increases or decreases in vegetative cover but is rather a change in the height above sea level. In other words, the effect of altitude on temperature is more important than the effects of vegetation on the Earth's surface temperature. At the lower altitude of Dena County where the temperature is relatively high and there is enough vegetation to grow, the vegetation cover is denser and more abundant and therefore there is a positive relationship between land surface temperature (LST) and vegetation cover index (NDVI).

Introduction: Different coastal ecosystems, especially mangroves, are exposed permanently and almost simultaneously to multiple environmental stresses and disturbances (geological, physical, chemical and biological) which are varied in terms of their characteristics over time and space. The direct result of these stresses and disturbances is the reduction in area and health of mangroves and the subsequent exacerbation of global warming and other consequences of climate change, reduced coastal water quality, loss of biodiversity and degradation of coastal habitats. Considering the adverse consequences arising from the reduction in mangrove forest area, prioritizing management actions and providing appropriate infrastructure is essential to prevent a decrease in the extent of these ecosystems. Achieving this goal depends on having accurate and sufficient information and knowledge about the process of changes in the extent of mangrove forest habitats over time which can play an important role in the efficiency and success of rehabilitation programmes and the development of these ecosystems. Hence, the aim of this study was to investigate the long-term changes occurred in areas of mangrove forest of Hormozgan Province.Materials and methods: In this study, Landsat images from 1986, 2000, and 2016 were used to study changes in the extent of mangroves over time. The necessary pre-processing was doneconducted on images using Idrisi software. After extraction of the mangrove vegetation maps in the aforementioned years, changes in mangroves of the Khamir, Qeshm, Tiab, Sirik and Jask habitats were analyzed in ArcGIS software and the average values of areas of mangroves were calculated for two periods, namely pre- and post- 2000, and during a 30-year period.Results and discussion: The accuracy assessment of the classified images showed that the overall accuracy was equal to 92%. The results also showed that among the zones investigated (Khamir, Ghesh, Tiab, Sirik andJask), Khamir habitat zone had the highest average annual value of area reduction (equal to -4.64 h/yr) and Sirik habitat zone had the highest average annual value of area expansion (equal to 23.5 h/yr) during the 30-year period. The results also showed that during period of 2000-2016, Sirik and Qeshm zones had the highest average value of expansion and reduction in area, respectively (equal to 32.47 and -21.38 h/yr, respectively). Analysis of mangrove area changes in different habitats showed that, despite the reduction in the extent of all mangroves in the period after 2000, the mangroves of Sirik habitat had significant increase in area in this period compared to the period before 2000 which was due to forestation with Avicenna and Rhizophora in the mud flats of this habitat in recent years.Conclusions: The results of the study of changes in the areas of mangroves of Hormozgan Province showed that the trend of change the in area covered by the mangroves of Hormozgan Province over a 30-year period has been increasing from the coasts of the Persian Gulf to the Oman Sea; this indicates the impact of various environmental factors affecting the changes in the extent of the mangroves of the province. Finally it can be said that the results of this study, by providing up-to-date and accurate information about areas changes of mangrove habitat in Hormozgan Province, can help significantly to the planning of effective actions to protection and restoration of these habitats.

Introduction: Khuzestan Province is one of the regions of Iran which has been most affected by the newfound phenomenon of dust storms due to recent droughts. Dust storms, which in some cases are considerably concentrated and accompanied by a reduction of horizontal view to 20 meters, causes various problems such as harmful effects to human health, absorption or dispersion of sunlight and affecting the region’s temperature, a negative impact on agricultural activities, reduced visibility and road transportation problems and tens of health, environmental and economically undesirable effects. So, due to the importance of the issue, a mineralogical and geochemical study of dust storms has been conducted in order to determine their probable sources, the environmental characterization of existing elements in dust and their role in polluting the environment.Materials and methods: In order to conduct dust sampling, a glass table was designed with edges to the height of 5 centimetres and an area of 1.5 square meters. In this matter, from April 2011 studies were conducted for 2 years in Khuzestan Province (Abadan, Ahvaz and Bostan). Through investigating previous studies and extracting the specified focuses, five sources have been identified for dust entering the country.30 dust samples were collected and analyzed for elemental and mineralogical analysis conducted. The mineralogical analysis was conducted by using powdered samples and a Siemens XRD diffraktometer D5000 ICP-OES JY70 PLUSand an ICP Optical Emission Spectrometer (model Varian 735-ES) were utilized for elemental analysis. All the tests were conducted at the laboratories of the Geological Survey and Mineral Explorations of Iran.Results and discussion: According to previous studies, during finding sources through investigation over the period from 2011 to 2012, 50 sources were identified, namely that much of the dust storms which have affected Khuzestan Province during 2011 and 2012 originated from the following regions. Region 1: Northwest Iraq and eastern Syria, both sides of the Euphrates River (with at least 9 cases of dust storms over the 2 years). Region 2: wetlands and dried lands in southern Iraq (Mesopotamia) with at least 5 ases of dust storms in Khuzestan. Region 3: neighbouring and northerly lands of Lake Tharthar in Iraq with 4 cases of dust storms. Region 4: western areas of Iraq (Anbar Province) and eastern Syria (Hamus Province) with 3 cases of dust storm occurrences over two years. Region 5: northern borders of Saudi Arabia and the East of Jordan with 2 cases of dust storms during the period studied. Mineralogical studies of dust in the destination area showed that there are calcite, quartz, clay minerals and an insignificant amount of dolomite, gips and feldspar in the focus areas of regions 1, 3, 4; and halite, dolomite, quartz, and gypsum in the southern focus areas of Iraq (region 2). This, then, associates the sedimentary environment related to erosion and evaporation (dried lakes and wetlands and sediments of old lakes) as the geological source of these particles. Most of the heavy metals and toxic and radioactive elements in the dust are highly enriched. These enrichments are influenced by hydrocarbon materials and upstream processes of the oil industry, contamination caused by repeated wars and use of microbiological and chemical weapons containing radioactive elements, accumulation of clay particles due to the high absorption capacities of some of the heavy metals, drying up of wetlands and land of the source region and creating evaporating conditions, most of which is anthropogenic.Conclusion: The storms entering Khuzestan Province derive from dried up wetlands and lakes and the sediments of old lakes and high enrichment, creating an unusual level of elements in dust due to the high absorption capacity of the elements into clay particles resulting from hydrocarbon materials. It is also caused by effects of the imposed war on Iran (with Iraq) and the drying of wetlands because of human activities.

Introduction: Contamination from agricultural inputs, particularly herbicides, is one of the most important environmental challenges and the use of modern technologies such as herbigation has intensified this problem. Thus, employing optimal management strategies based on knowledge of herbicide behaviour and processes in soil is necessary. The objective of this study was to assess quantitatively the herbicide adsorption-desorption behaviour in soil in the laboratory and under real field conditions.Materials and methods: Consequently, metribuzin was applied to the experimental plots using the herbigation (HRB) and conventional spraying (CS) methods, and to laboratory samples. After inspecting the adsorption and desorption behaviour of herbicide by batch and centrifugal methods, different models of equilibrium adsorption were fitted to the data.Results and discussion: Results indicated that, due to the low amount of organic matter and clay in the soil, herbicide adsorption was generally weak in all three types of treatment and that the overall process followed the Freundlich model. The results further showed that in all three treatments because of the adsorption mechanism’s weak hydrogen bond, a large portion of the adsorbed molecules desorbed after four washing cycles. However, in the laboratory and herbigation treatments, the amount desorbed was relatively less and, due to the diffusion of molecules into inter-aggregate pores, a small hysteresis can be seen.Conclusion: In conclusion the results show, the adsorption amount in laboratory and herbigation treatments is greater than conventional spraying treatments due to a higher moisture level in the soil and increasedhydrophilic sites on organic matters and diffusion within the inter-aggregate pores. Therefore, the methods of pesticide application affect the adsorption and desorption behaviour of it. So pesticide application by herbigation is suggested in order to reduce losses and increase efficiency in the field.

Introduction: A wide range of organic chemicals enter into the environment, intentionally or unintentionally, creating public concern. Petroleum hydrocarbons represent one of these organic pollutants threatening various hazards to terrestrial and marine ecosystems. We need cost effective technologies for restoration of contaminated sites, and bioremediation is one the methods which has been used in recent decades. In this method, microrganisms and plants are used to remove, degrade or stabilize pollutants. Biological methods are economically more acceptable than physical and chemical methods. The current study aims to identify the best bacteria for decomposing petroleum hydrocarbons in the soil at Tabriz refinery.Materials and methods: In this study, oil contaminated soils were collected from a refinery in Tabriz and, in order to identify them, a synthetic Bushnell Haas Mineral Salts medium (BHMS) was used. After the enrichment process, separation and purification were performed. Two strains were selected for molecular identification based on the higher growth in a medium containing crude oil. Molecular identification of the selected strains was conducted after DNA extraction and sequencing of the 16S rRNA gene. The growth of bacteria in both light and heavy diesel was recorded using a spectrophotometer at wavelengths of 560 nm. To assess the production of a biosurfactant, several tests including a drop collapsing test, oil displacement test as well as emulsification activity and cell surface hydrophobicity were performed.Results and discussion: The sequences obtained were compared with those of the National Center for Biotechnology Information (NCBI). The isolated bacteria with 98% similarity belonged to Pseudomonas aeruginosa and Achromobacter spanius. Both bacteria showed growth in all the three oil components, however, Achromobacter spaniushad higher growth rate compared to Pseudomonas aeruginosa. The latter could decompose 67 percent of light diesel in 9 days. Although both bacteria could produce a biosurfactant, Achromobacter spanius had higher hydrophobic cell surface and emulsification activity.Conclusion: In the current study we introduced Achromobacter spanius as an efficient bacterium for the decomposition of heavy and light diesel and crude oil. Based on the results, it is recomended that the ability of the identified bacteria in petroleum contaminated terrestrial and aquatic environments be investigated further.

Introduction: According to distribution requirements and the broad distance between production and consumption centres in Iran, linear infrastructure development plays an important role and should be considered as a vital necessity. Routing problems include many factors which are often incompatible with each other and incompatibility amongst parameters causes significant delays in the process of routing. Hence, it is of interest that use of the new utilities in Geographic Information Systems (GIS) to optimize the routing process can resolve the difficulties faced in decision-making steps.Materials and methods: This study aims at optimizing oil pipeline routes from wells drilled to the refinery by using different scenarios and to consider is OR ness and AND ness. In the beginning preparation stage all necessary spatial data Like, Geology, land cover, slope, Dem, Fault, Main, River, stream which are required to find the optimal route for establishment of oil transmission line have been collected than Standardization and Preparation by using reducing and Increasing linear weighting function. AHP process has been hired in order to find spatial weight of each parameter’s effectiveness in terms of cost of establishment and oil line interaction with its surrounding environment. Ordered weighted average (OWA) method has been applied to integrate spatial data and achieve the result, cost layer. Dijkstra's algorithm has then been used to find the optimal route between the location of wells and refineries.Results and discussion: The results show that with increase in the value of α, the amount of cost, average slope and height of the oil transit route increase. In scenarios with 𝛂<𝟏, higher values are given to high-value pixels. While higher order weights are assigned to values with a lower numerical value in the same position. Therefore, the length of the route from the All (AND) scenario to the At least one (OR) scenario decreases.Because the Dijkstra's algorithm is a single-objective algorithm and aims at extracting the path with the leastcost. Because at every move, Choose a pixel with the lowest Accumulative cost as the direction of motion and do not pay attention to the length of the route.Conclusion: By comparing the existing route and the paths obtained from the Dijkstra's algorithm in different scenarios based on the factors of length, cost, mean slope and height of the route extracted In Almost All, Most, and Half (WLC) scenarios, are better than the other options in terms of techno-economic and environmental conditions in study area. Other scenarios have produced better results than some of the existing ones in some of the factors. Providing Various Results, With ORness and tradeoff this method has great flexibility in estimating the needs and priority of decision makers in the field of petroleum industry to design optimal transmission lines.

Introduction: One of the main problems in rice cultivation and production is the lack of water resources, especially during periods of low rainfall which affect vegetative growth rate and the level of yield. Drought stress has been well documented as an effective parameter in decreasing crop production, and developing and releasing new varieties which are adapted to water deficit conditions can be a constructive approach to overcoming unsuitable environmental conditions. Hence, the characterization of genetic diversity and germplasm classification for parental selection in breeding purposes is of great importance.Materials and methods: In order to evaluate the adaptation of rice genotypes to drought stress and to identify tolerant and sensitive genotypes, 20 genotypes were studied using a factorial randomized complete block design with three replications at the Rice Research Institute (Rasht). During growth stages, some traits were recorded such as plant height, total and fertile tiller number, flag leaf area, panicle length, filled and empty grain number, 100-grain weight, number of days to maturity and yield.Results and discussion: Mean comparison showed that the lowest percentage changes in traits among local varieties (Hashemi, Alikazemi and Sangjo) and improved cultivars (Dorfak, Sepidrood and Shiroodi) respectively. Cluster analysis using Ward’s minimum variance and squared Euclidean distance for agronomic traits divided the genotypes into two groups. The separated varieties were grouped in clusters with high quality local and improved cultivars. The study found that the different groups show genetic variation in rice genotypeson the basis of morphological traits and this guides us to select the most different and the best for hybridization programmes, especially to hybridize with local varieties in order to create new varieties resistant to stress. The result of factor analysis based on the principal component showed that factors three and four accounted for 73-85 of total variance.Conclusion: For the selection of genotypes with high yield and stress tolerance in rice, total and fertile tillers, days to maturity, flag leaf area, panicle length and 100-grain weight could be considered through estimating suitable selection indices for these traits.

Introduction: Nowadays, the use of chemical fertilizers containing iron (Fe) in order to compensate for iron deficiency symptoms in apple orchards may be inevitable, but is not compatible with organic farming. Most of Iran’s temperate zone fruit orchards are located in limestone areas and iron deficiency symptoms are observed in these areas. As a result, growers use significant quantities of fertilizer containing iron that, in addition to the cost, disrupt the balance of nutritional elements in the soil.Materials and method: The study was carried out in order to find rootstock resistant to iron deficiency through the two methods of iron hunger and bicarbonate stress and to evaluate the endurance of iron deficiency-induced chlorosis in nine hybrid apples, Gami Almasi hybrid apple trees and Malling Merton 106 and their progeny were used in terms of aquiculture. Mean comparison was performed using the Duncan test at a 5% probability level using SPSS software.Results and discussion: In general, the results showed that Gami Almasi root stock was more tolerant to Fe deficiency-induced chlorosis compared to Malling Merton 106 and their progeny. Chlorophyll index, chlorophyll fluorescence, total chlorophyll content, total iron and active iron of sixth leaves from the final bud were found to have a significant difference with the Maling Merton 106 and, at times, with their progeny. The pH and Ec of the pots' drainage were influenced by the type of root stocks.Conclusion: In both methods investigated in the study of Gami Almasi, in comparison with other bases of the chlorophyll index, the visual rating of iron-deficiency, the concentration of chlorophyll in leaf from the sixth the end of the bud and the concentration of total and active iron in leaves showed better performance.

Introduction: The lack of efficient use of water as a production input has led to wastage of a significant amount of this input, which is financed at a great cost. Most provinces of the country have been facing water crisis for decades. Symptoms of this water crisis have been observed in some plains of Khorasan Province since the early 1970s, and this crisis has intensified in the last decade due to the lack of proper management of water resources. Therefore the present study, using a dynamic approach, studies the management of water resources in the Tabarkabad Dam in Quchan.Materials and methods: In this paper we put forward an easy-to-implement methodology for solving deterministic or stochastic dynamic programming problems within a standard optimization package such as GAMS. We found that the use of orthogonal polynomials was especially helpful in implementing approximation methods for the iterative computation of the infinite-horizon value function, due to their superior convergence properties over standard polynomials. This method is described using the case study of Tabarkabad Dam in Quchan city. For this purpose, data related to the Tabarkabad Dam were collected through the National Dams Information System for the years 2008-2016. Also, data relating to the estimation of the agricultural water demand function in Quchan city were obtained through a questionnaire prepared by the Ministry of Jihad-e-Agriculture.Results and discussion: Based on the results, comparing the actual and simulated values for the dam reservoir (state variable) and water release (control variable), it is determined that the simulations performed with orthogonal polynomial Chebyshev approximation were appropriate. Finally, based on the results, the netpresent value of water allocated to agriculture at Tabarkabad Dam in the studied period is 1471205 Rials and the allocation of water is equal to 24.745 million cubic meters per year.Conclusion: Considering the results obtained and the proper approximation of simulated values, we can use the proposed method of this study to solve stochastic dynamic programming problems, especially in the field of water resource management. Also, by using the annual allocation of water and taking account of other regional constraints, we can provide a suitable cropping pattern for the sustainable use of agricultural water for the coming years in the fields covered by the Tabarkabad Dam.