JWSS - Journal of Water and Soil Science

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In order to describe soils polluted with hydrocarbons, the amount and distribution pattern of soil heavy metals (Ni, Cd) in soils were studied. Soil samples were taken from one of the western oil field of Iran. The field was naturally exposed to crude oil spillage into soil and consequently was environmentally polluted during the development, production, transportation and storage of crude oil. Sampling was started near the oil wells with maximum relative contamination and continued to the remote places based on grid sampling pattern. Samples were characterized by physicochemical analysis. The results revealed different levels of total hydrocarbons (from 0.12 to 2.99 mg/kg of dry soil), Ni (from 32 to 136 mg/kg. of dry soil) and Cd (from 0 to 4mg/kg of dry soil). In addition, the role of soil agents such as pH and EC and sedimentary indexes was considerable in controlling the pollution trend in the studied area. Finally, by interpolation module and prediction of unknown values via Kriging techniques, the expansion plans were created. The extracted plans obviously illustrated the decrease in the levels of pollution indexes with the increase in distance from the given centers of pollution

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The type and intensity of soil erosion in a region generally depend on climatic conditions, ups and downs, soil and land use. Of these, land use is most important. Using different systems of ploughing after unconscious and non-scientific change of land use affects soil physicochemical characteristics. This fact especially in marginal lands and mountainous regions is more visible. In order to investigate sensitivity to soil loss and erosion in various land uses of Aghajary deposits, part of Margha catchment with an area of 1609 hectares in Izeh city was selected. This was to determine the relationship between soil loss by rain simulator and some soil physicochemical characteristics like percentage of very fine sand, sand, clay, silt, pH, Ec, moisture, Calcium Carbonate and organic materials in different land uses. Then, sediment sampling in 7 points, three replicates and in various intensities of 0.75, 1 and 1.25 millimeters in minute in range, residential and agricultural land uses was done using rain simulator. In order to investigate effective factors in sediment production and erosion, samples of soil layers (in depth range of 0-20 cm meters) equal to the number of sediments were taken. For statistical analysis, EXCEL and SPSS 11.5 software were used. In total, the amount of runoff in residential land use was highest and in agriculture land use was lowest. The amount of sediment in agriculture land use was highest and in residential land use was lowest. Then, the most important factors in sediment yield were diagnosed by multi regression. The results showed that sediment yield and erodibility in land uses have meaningful differences in various intensities of precipitation. Regression models showed that in the production of sediment in various land uses, from among the measured factors, silt, sand very fine, lime, Ec, organic materials and pH had the greatest role. Sand percentage in the residential land use, and very fine sand and organic matter in agriculture land use had the most important role in sediment production. But in range land use, moisture percentage and pH had the biggest role in sediment production.

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Most furrow irrigation systems have low performance due to deep percolation at the upstream end and tailwater runoff at the downstream end of the field. To eliminate this problem improving furrow irrigation performance is necessary. Since the inflow discharge has high effect on infiltration along the furrow which consequently affects the application efficiency and water distribution uniformity, it would be important to apply different furrow inflow hydrograph shapes based on the field data such as field slope, soil texture and furrow length to save water. To produce different furrow inflow hydrograph shapes, an automatic valve which was connected to a stepper motor was designed to change the inflow discharge with time according to the desired inflow hydrograph shape. The experimental field was located at Isfahan University of Technology. A constant head water delivery system to the furrows including the automatic valve was installed in the experimental field and the tests were conducted for different inflow hydrograph shapes. The comparison of the measured furrow inflow discharges with the simulated furrow inflow discharges produced by the automatic valve showed that the automatic valve can produce different furrow inflow hydrograph shapes with high accuracy.

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In order to evaluate the effect of concentration and time of foliar spraying of nitrogen fertilizer as supplemenfary to soil nutrition on grain yield and some important traits of rapeseed (Hyola401), an experiment was conducted in complete randomized block design with 16 treatments and three replications in in 2008-2009, 2009-2010 growing seasons, and in 2003-2005 growing seasons in paddy fields of Rice Research Institute of Iran (Rasht). In this experiment, nitrogen concentration (from urea source) at two levels (5 and 100.00) and application time at seven levels including 1-seedling stage: 6-8 leaves 2: beginning of stem elongation 3: prior to flowering 4: 6-8 leaves + stem elongation 5: 6-8 leaves + prior to flowering 6: stem elongation+ prior to flowering 7: 6-8 leaves + stem elongation+ prior to flowering with two control treatments including zero nitrogen fertilizer and basal fertilization as 1/3 at seed sowing, 1/3 at stem elongation and 1/3 prior to flowering stages of 180 kg pure N ha were considered. Results of combined analysis showed significant differences between the experimental treatments in most traits. Spray application of nitrogen (100.00) in stem elongation+prior to flowering stage produced maximum silique length (6.8 cm), number of secondary branch (7.1) and plant height (141.1 cm). Also, the spray application (100.00) in 6-8 leaves+stem elongation+ prior to flowering stage had maximum biological yield (10684.6 kg.ha-1), grain and oil yields (3686.2 and 1489.3 kg.ha-1, respectively) and the maturity period (202 days). Spray application (100.00) in stem elongation+ prior to flowering stage did not induce significant difference with spray application (100.00) in the three stages. Maximum oil content was observed in control treatment (zero nitrogen fertilizer) with an average of (44 %). According to the results of the present experiment, it seems that spray application of nitrogen (100.00) at final growth stage of rapeseed (stem elongation+ prior to flowering stage) increases grain and oil yields.

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The modeling of yield response to water is expected to play an increasingly important role in the optimization of crop water productivity (WP) in agriculture. In this study, the CropSyst model was used to simulate two local rice varieties yield response under five irrigation treatments consisting of continuous flooding irrigation and irrigation at 0, 3, 6 and 9 days after the disappearance of water from the soil surface. The experiment was conducted at Rasht region during two growing seasons of 2003 and 2004. The model was calibrated using the first year data and validation of that was done using the second year data set. The result of F test shows that there was not a significant difference between the measured and simulated yield at confidence level of 99%. The relative errors of yield estimation were obtained between -0.81 to 12.58% and -2.4 to 19.42% for Binam and Hasani cultivars in 2003, respectively. These values were 0.83 to 16.4% and -2.82 to 21.27% in 2004, respectively. The results showed that due to the CropSyst model ability in simulating yield of rice under different irrigation regimes, this model can be used to explore management optimum options to improve rice water productivity

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Soil erosion is one of the most important factors affecting soil quantity and quality and is environmental problems in developing countries like Iran. It can have deteriorating effects on ecosystems. This research was carried out in farm lands of the Chehel-Chai watershed, Golestan province to investigate the effect of soil properties on runoff and soil loss. Runoff and soil loss were measured in a completely randomized design in 36 plots with 10×10 m sizes in farm lands. For this reason, this study was conducted using rainfall simulator with 2 mm/min intensity and 15 min duration in 4 replicates. Soil samples were also taken in each plot. Sampling was conducted in October 2009. Results of the Pearson correlation showed that among soil properties, the contents of the lime, silt and fine sand had positive correlations with runoff at 1% confidence level. Also, soil surface resistance at 1% confidence level, the contents of the organic matter and nitrogen at 5% confidence level had negative correlations with soil loss. Finally, the results of multiple linear models showed that the content of lime is effective in estimating runoff and soil surface resistance, and organic matter is effective in estimating soil loss.

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Limited information is available about the effect of preceding crop residues on bioavailability of zinc (Zn) in calcareous soil and its accumulation in wheat grain. In this experiment, residues of five crops including safflower (Carthamus tinctorius L.), sunflower (Helianthus annuus L.), bean (Phaseolus vulgaris L.), clover (Trifolium pretense L.) and sorghum (Sorghum bicolor L.) were incorporated into a calcareous Zn-deficient (0.5 mg kg-1) soil. A treatment without crop residue was also used in the experiment. This experiment was conducted in research greenhouse of Isfahan university of technology in 2010. Two wheat cultivars (Triticum aestivum cvs. Backcross and Kavir) differing in Zn-efficiency were studied in the experiment. Incorporating crop residues into the soil resulted in an increase of grain Zn concentration in both wheat cultivars although this increase was dependent on the preceding crop type. The greatest increase of grain Zn concentration occurred in the sorghum residues treatments. Although application of crop residues significantly decreased grain phytic acid to Zn molar ratio (as Zn bioavailability criteria for consumers), this ratio was still higher than 15, the critical Zn bioavailability level for consumers in foods. According to the results, despite the increase in the total Zn content, the bioavailability of Zn in wheat grain was not affected by crop residue treatments.

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The transport process of chemical-fertilizers, radioactive materials and other solutes in soils and porous media is important to understand the environmental and economic effects of industrial, agricultural and urban waste disposal methods. In unsaturated porous media, large gradient in aqueous osmotic potential derives significant water vapor fluxes towards regions of high solute concentrations. In this research, the effects of osmotic potential (resulting from salinities of 0.5, 1 and 1.5%) on water vapor transport in three soil textures (silty clay loam, loam and sandy loam) were examined by using a physical laboratory model. Then, the experimental results were compared with Kelly and Selker (2001) model for validation of the predicted water vapor transport. The results showed that the rate of water vapor transport reduces significantly as soil texture gets heavier. For example, in salinity of 0.5% and 5th day of experiment, the amount of transported vapor in sandy loam, loam and silty clay loam soils was 0.362, 0.196 and 0.12 kg/m2, respectively. Large osmotic potential near the high solute concentration in soils caused significant vapor movement toward dense solutions. In salinity of 1.5%, transported vapor in these soils was 1.47, 0.723 and 0.38 kg/m2, respectively. Total water vapor movement until the 15th day was more than the 5th day. Comparison of experimental results with Kelly and Selker model results, using Mathcad PLUS 6.0 software, showed a good agreement between the observed and predicted data. Since water vapor delivered from uncontaminated soils to the contaminated soils can result in increased contaminant plume volume, these physical and chemical processes must be included in the predictive models of contaminant transport in the vicinity of concentrated sources

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The aim of this research was to determine the effects of Camphorosma monspeliaca species on soil variables in its habitat. Ecological positive or negative effects of new species on environment must carefully be examined before allowing their plantation in vast areas on the other hand these species with their special characteristics have special effects on their surrounding environment that should be considered. Camphorosma monspeliaca is one of the non-native and adapted species in Chaharmahal va Bakhtiari Province that its unique habitat has 3500 ha area. Effect of this species on new environment requires more studies on their several different aspects. Here we studied effect of this species on soil in order to assess ecological effects of this species on environment. This species distributed in all of the landscape but most distribution of species located at southern and northern aspects and land with flat topography.This species can establish in non saline soil, loam and clay loam texture with different value of organic matter, lime and gypsum. The research was carried out at four stages of information and background collection, field sampling, soil test and statistics analysis. The research method was based on comparison among adjacent stand and stands of this species. Soil variables in two surface (0-10 cm) and depth (10-30 cm) were measured. Result showed that there was significant difference among adjacent stand and stands of this species in terms of SAR, OM and Sand in stands of this species were greater than the adjacent stands. This species increased content of organic‌ matter and amounts of SAR, OM and Sand. From the results obtained on three topography position, despite of negative effect of Camphorosma monspeliaca on under soil with increase of SAR, it can be concluded that Camphorosma monspeliaca had a positive effect on soil organic matter and soil texture

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This research was carried out in a hydroponic culture to investigate the effect of Zn nutrition on phytosiderophore release by roots of three bread wheat genotypes (Triticum aestivum L. cvs. Rushan, Kavir, and Cross) differing in Zn-efficiency. The wheat seeds were germinated in sterile sand and two weeks later the plants were transferred to nutrient solution containing different Zn levels. Phytosiderophore released by plant roots was collected ten days after applying Zn treatments and measured using resin-Cu-mobilization test. A month after their transfer to nutrient solution, the plants were harvested and Fe and Zn concentrations in root and shoot were measured, and total amounts (uptake) of these nutrients were determined. Zinc addition increased concentration and total amount of Fe and Zn in shoot in Rushan genotype, while it had no significant effect on concentration and total amount of Zn in shoot and root of Kavir and Spring Back-Cross-Rushan genotypes. Addition of Zn to the nutrient solution decreased concentration and total amount of Fe in shoot of all wheat genotypes. On the other hand, Zn nutrition increased root Zn concentration in Rushan and Kavir genotypes, while it resulted in significant decrease of root Zn concentration in Back-Cross-Rushan genotype. Effect of Zn nutrition on the amount of phytosiderophore release by roots of wheat genotypes was different. Zinc nutrition resulted in an increase of phytosiderophore release by roots of Rushan, while it had no significant effect on phytosiderophore release in other wheat genotypes.

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Different root water uptake models have recently been used. In this article, we use evapotranspiration data and soil water content data obtained from lysimeter measurements and root distribution in soil data obtained from olive tree to evaluate the accuracy of root water uptake models in predicting the soil water content profiles. Depth of lysimeter was 120 cm which was filled with clay-loam. Lysimeter recorded values of input and output of water and accurate value of evapotranspiration was also calculated. Soil water content distribution was measured using a TDR probe in lysimeter during the experiment. Feddes model with the root length density was used to account for the role of root distribution in soil. The flow equations were solved numerically with the measured evapotranspiration data as input, and the predicted soil water content profiles were compared with the measured profiles to evaluate the validity of the root water uptake models. The comparison showed that the average of relative error index for Feddes model was 10 %. Based on the results, about 90% of root uptake in olive tree happened at the depth of 40 centimeter

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This study was conducted to assess the long-term effects of soil texture and crop management on transport of lithium (Li+) and bromide (Br-) under unsaturated flow conditions. Treatments were two different soil textures of clay loam and sandy loam to be cropped with either wheat or alfalfa for 4 years. Undisturbed soil columns were taken for the steady-state flow condition using tap water prior to applying a pulse of 0.005 M (C0) LiBr solution as the influent. Four pore volumes (4PV) leaching for each column was obtained. Bromide and lithium concentrations of the effluent (C) were measured in 0.2PV intervals using bromide selective electrode and flame photometer, respectively. Relative concentrations (C/C0) of Br- and Li+ in the effluent were drawn vs. pore volumes. The results showed that the effluent concentrations were significantly affected by crop type and soil texture (in combination by soil structure). The breakthrough curves illustrated the early appearance of Br- in the effluent due to anion repulsion and retarded movement of Li+ because of surface adsorption through the soil columns. Both Br- and Li+ concentrations decreased with time and converged at low levels justifying the minor effect of macropores on continuation of leaching and final transport via soil matrix. The Br- and Li+ concentrations were higher in the effluent of clay loam soil under alfalfa due to higher structural stability compared with sandy loam soil under the same crop. It was also shown that in both soil textures the concentrations of Br- and Li+ appeared to be higher under alfalfa than under wheat, indicating the importance of crop management in contaminant transport compared with soil texture. The trends of breakthrough curves of Li+ were similar to Br- with lower concentration in effluent as a result of its adsorbtion on active surfaces.

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Groundwater is the most important source of water supply for agricultural purposes in arid and semi-arid areas. In many areas, excessive use of high quality water resources leads to reducing the available water resources and turning to the use of low quality water resources. Thus, knowing the temporal and spatial variation of groundwater quality is a necessary factor for implementation of sound water resource management and establishment of the suitability between water quality and its usage. In order to investigate water quality changes, this study was divided into two phases. In the first phase, for evaluation of the quality of groundwater for irrigation 76 wells were sampled in Bahadoran plain, in the year 2006. The SAR, EC, ions B3+ and Cl- were analyzed as the evaluation indexes. Then, using geostatistical methods the maps of each parameter were prepared. Finally, considering FAO criteria, these maps were overlaid and separate water quality maps were derived. The EC map indicated that in 48 and 52 percent of the groundwater lies in severe and slight to moderate restriction class for irrigation purposes. Moreover, the thematic map of infiltration restrictions indicates that the groundwater has no restriction in 66 percent of the area while 11% of groundwater causes low to moderate and 23 percent causes severe limitation. In the next phase, to examine changes in groundwater salinity during a 5-year period, 38 wells were sampled and the groundwater salinity map for the year 2011 was prepared. Finally, using subtraction of the salinity maps of given years, the salinity changes map was derived. The results of thematic map showed that groundwater salinity increased in 26.47 percent of the study area. In contrast, there was a decrease of about 31.14 percent in groundwater salinity over the 5-year period while 42.39 percent of the region’s groundwater remained unchanged. Since the study area is under cultivation of pistachios and salt threshold of this tree is 8 ds/m so the area of about 8 percent of the area was added to the previous limited areas. Therefore, irrigation management and planting development plan in Eastern and Southeastern areas should be revised.

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Soil erodibility and gully erosion and their expansion occur under geological formation and soil characteristics. This study aims to find the rate of soil and formation effects on gully erosion in Seifabad watershed. To that end, aerial and field work were used together to determine the rate & expansion of 17 gullies in 12 years' period from 1997 to 2009. The soils were sampled for each gully in 50% interval distance with 0-30 cm horizontal surfaces and >30 cm depth. Some factors were estimated from the soil such as EC, PH, Silt, Clay, Sand & limeston percentages. Statistical analysis was done using SPSS 14 through non-parametric tests such as Kruskal-Wallis & Mann-Whitney. Spearman coefficient was used to investigate the relation between volume of gully & litological factors. The results showed a positive correlation at 1% level for the PH with the gully erodibility in surface soil, but for the depth of soil this relation belonged to the silt percentage, and sand showed a negative relation at 5%level with the volume of the gully sediments. Finally, there was no statistical relationship between geological formation and the sediment yield in gullies.

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The main aim of flood water spreading in Iran is to recharge groundwater. Understanding the effect and efficiency of such projects is one of the most important activities in managing and implementing water spreading. The purpose of this study was to investigate the effects of water spreading on groundwater resources in Kohdasht plain. Data and information required including precipitation rate, groundwater level and groundwater exploitation were collected and analyzed for a ten year period. First of all, in order to assess the three variables test of normality was performed and then all the data was normalized. The results showed that before implementing the water spreading project, fluctuations of groundwater were proportional to utilization of groundwater resources, showing a declining rate. After implementing the project, a turning point on groundwater level was observed. Also, another turning point was recognizable in hydrological year 1377-1378. In addition to overexploitation, drought affected the aquifer so dramatically that standard index in hydrological year 1371-1372 decreased from 0.3 to -1.5 in hydrological year 1377-1378.

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The quantity and variability of soil organic carbon (SOC) is one of the most important indices to determine the effect of land use changes on the soil quality. Regarding long-term changes from rangeland to dry farming in the Roin area of North Khorasan, the objectives of this study were to investigate the effect of long-term land use changes on the SOC in different slope faces and use SOC as an index to make a proper decision about the future of land use in this area. 140 soil samples were taken from 0-15 cm soil depth of back slope position of north-, south-, west- and east-facing slopes of rangeland, dry farming, alfalfa dry farming and garden in 7 points. 14 soil samples were taken from irrigated farming, too. The results showed that garden and irrigation farming with averages of 2.03 and 0.78% have the maximum and minimum SOC content. The average of SOC content in rangeland was 1.40% that decreased by land use change to 1.04 and 1.27% in dry farming and alfalfa dry farming, respectively. SOC content in southern slope aspects showed a significant difference compared to other slope aspects. The most SOC content occurred in east aspects. It seems that after long-term land use changes, the SOC content have equilibrated to environmental and land use conditions. The average SOC content in different slope aspects except south one changed from 1.4% in rangeland to 1.11% in dry farming and 1.32% in alfalfa dry farming, which are a suitable value for semiarid regions. In conclusion, to protect land from degradation and considering this fact that dry farming is the main income of the people in the study area, it is recommended to stop dry farming on south aspects and continue on east, north and west aspects with conservation practices.

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Environmental pollution caused by heavy metals such as lead is a serious and growing problem. Due to the importance of wheat in the human nutrition, this research was conducted to study concentration of lead in the soil and also seeds of wheat farms in Khuzestan Province. Therefore, in the agricultural year of 2007-2008, the soil and wheat seed samples were collected from 100 farms whose locations were specified using weighing sampling method. The lead concentrations in soil (total and available), and wheat seeds samples were measured. The result revealed that lead concentrations in soil and seeds in none of the studied regions exceeded the respective critical levels (50 and 30-300 mg/kg, respectively). Ezeh with an average of 0.01 µg/kg had the lowest amount of lead in the wheat seeds, while Bagh‌Malek with an average of 190 µg/kg had the highest amount. The mean concentration of available lead in the soils of study region was 0.6 mg/kg. The concentration of available lead had a negative and significant correlation (r=-0.2*) with the ECe. Also, lead concentration in wheat seeds had a positive and significant correlation (r=0.3**) with the amount of calcium carbonate equivalent. More lead concentration in seeds of bread wheat cultivars showed its higher potential for accumulation of lead than durum wheat.

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The objective of this study was to evaluate the effects of crop residues management on soil physical and biological properties. The impacts of residue management on yield of forage corn and barley and soil micro-organisms population were also studied. The results showed that application of crop residues increased soil organic matter (22.2 %), saturated hydraulic conductivity (51.9 %), porosity (3.7 %), mean weight diameter (MWD) of the aggregates (5.4 %), and field capacity (5.8 %) and decreased bulk density (3.7 %) Whereas crop residues burring decreased soil organic matter (31.8 %), saturated hydraulic conductivity (36.6 %), porosity (0.5 %), mean weight diameter (MWD) of the aggregates (5.1 %), and field capacity (4.1 %) and increased soil bulk density (1 %). Soil water characteristic curves showed that the observed differences in soil water retention of application and burning residues treatments were higher at low matric suctions than those at high water matric suction. The results demonstrated that micro-organisms population significantly (P<0.05) decreased in residues burning treatment compared with the residues application treatment. Therefore, based on the results of this study residues' burning is not recommended in Ardabil.

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Copper is considered as one of the most important nutrient elements for plants. If its contents are concentrated higher than the standard value it can be considered as a pollutant element. The content of absorbable copper in the area around Sarcheshmeh copper mine can be significantly high. In this study, samples of soil were collected in summer through a particular sampling method with chimneys of Sarcheshmeh plant as the center of sampling area within a radius of 6km, in three different directions (Rafsanjan, Sarcheshmeh City and Sarcheshmeh mine) and. The total concentration of absorbable copper and some chemical properties of soil (i.e. pH and EC) were measured for 122 surface samples (depth of 0 to 35 cm). There was a significant negative regression between pH and total absorbable copper content, and a significant negative regression was observed between EC and total absorbable copper content. The best fitted model was spherical model, and Ordinary Kriging was applied to map the absorbable copper content. Results showed that most concentration of copper occurred in the Rafsanjan direction. Also, regarding wind orientation which blows towards Rafsanjan, the chimneys probably have a significant effect on increasing copper content in Rafsanjan moreover, the copper content is substantially higher around chimneys than other areas. Also, transition of copper elements from chimneys by wind can be significant up to 4 km from Sarcheshmeh plant.

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Modernization of irrigation canals as an operation improvement tool is essential to promote the performance of canal networks and indeed requires control systems. Proportional integral derivative (PID) algorithms have more applications than the other controllers in different places of the world, but tuning these controllers for different hydraulic conditions of canals is considered as a major problem for designing control algorithms. Since the bottom slope is one of the effective factors in the water flow dynamic behavior, in this research, the distant downstream Proportional Integral Derivative feedback control with decouplers was designed with a change in longitudinal slope in a reference canal and its performance was investigated. The canal characteristics were used to tune this controller and the system identification as a new method was applied for determining canal characteristics. SOBEK hydrodynamic model modulated with MATLAB software was used to design and run the control algorithms, and slope influence on water flow behavior, tuning controller, and coefficients of controller were investigated with different values of slope. Then, controller performance for hypothetical period of operation in various scenarios was evaluated with computation performance indices. The results showed less resonance behavior of water flow and less potential of controller in steep slope