Mohammad Reza Mosaddeghi - Academia.edu (original) (raw)

Papers by Mohammad Reza Mosaddeghi

Water Resources Management

In this study, wetting patterns around the reservoirs with different permeability (low, medium, a... more In this study, wetting patterns around the reservoirs with different permeability (low, medium, and high) were assessed in the eld and simulated using the HYDRUS-2D/3D software. The results showed that the highest soil water content was observed near the reservoir and it decreased with increasing distance from the reservoir. In the high permeability treatment, a large volume of water was released for almost three days, so that, more water was deep-percolated and lowered the soil water available to plant roots. In the low and medium permeability treatments, the water content slowly moved and observed that the maximum soil water content occurred in the 20-40 cm layer overtime. The HYDRUS-2D/3D software was able to simulate water ow and soil water content during the growth period of plants with a high correspondence between measured and simulated soil water contents (R 2 = 0.90-0.95). 1 Introduction Water scarcity in the arid and semi-arid regions is a major concern. High-performance irrigation systems, such as surface or subsurface drip irrigation systems, are often recommended to overcome this problem and to dramatically increase the water use e ciency over that of traditional irrigation systems (Kandelous and Šimůnek, 2010). Subsurface irrigation with a ring-shaped emitter is one of the irrigation techniques in arid lands. Emitters are usually made from rubber although ring-shaped emitters have been successfully used for irrigation; its current design and operation are purely empirical. Besides, the current design of the ring-shaped emitter does not allow one to easily detect malfunctions because the emitter is fully covered with a permeable textile. As a result, it is not easy to repair it quickly (Saefuddin et al., 2019). Transient simulation models allow one to consider the physical processes governing the ow of water and chemicals in the unsaturated root-soil zone and consequently to evaluate the shape and the dimension of the wetting patterns as a function of the amount of applied water. The knowledge of the wetted soil volume dimensions as a function of time contributes, for each soil type, to identify proper design parameters (emitter spacing and distance between laterals) and the duration of irrigation providing to wet a xed soil depth (Provenzano, 2007). Deterministic models de ne mathematically individual processes as well as interactions between them, and each set of input data leading to a unique and reproducible prediction (Šimůnek et al., 1999; Wagenet and Hutson, 1992). Using physically based simulation models also contributes to develop management scenarios and strategies for irrigation, aiming to nd indications for water saving and consequently for increasing water use e ciency. To assess the accuracy of the models, it is necessary to proceed for the calibration and validation by using experimental measurements (Provenzano, 2007).

Iranian Journal of Applied Ecology

Severe natural resources utilizations, disregarding their real value and environmental potency, p... more Severe natural resources utilizations, disregarding their real value and environmental potency, pose many hazards in developing countries. Many rangelands have been converted to agricultural fileds to achieve more immediate income. This study, aimed to investigate the economic impacts of converting good and poor rangelands to dry farmlands in terms of soil and water conservation services in Fereidounshar-Isfahan. Hydraulic properties and infiltration status of various land uses were studied using tension infiltrometer. MPSIAC model was also used to estimate soil erosion and sediment yield in the studied area. Economic values of different soil and water conservative services were calculated using Replacement Cost approach. According to the results, good rangeland had the least amount of run off (6.66 mm), erosion (298.14 m 3 .km-2 .year-1) and sediment yield (129.42 ton. km-2 .year-1) compared to the other land uses. The economic gains of soil and water conservative services from each hectare of good and poor rangelands compared to dry farmlands were at least more than 20.38 and 13.19 million Rials in a year, respectively, which is equal to economic gains of not converting each hectare of rangelands in a year. Consequntly, in order to manage the lands holistically, based on principles of sustainable development, it is proposed to maintain rangelands.

Minerals

Soil characteristics, especially clay content and clay type, have significant impacts on splash e... more Soil characteristics, especially clay content and clay type, have significant impacts on splash erosion. This investigation was conducted to determine the effects of clay content and clay type (zeolite, phlogopite, bentonite, and kaolinite) on the shear strength and splash erosion of clay–sand mixtures compared with a clay soil under controlled conditions. Clay–sand mixtures were prepared by mixing 15, 30, and 45 kg 100 kg−1 of the selected clays with pure sand and a clay soil; these mixtures were pre-treated with three levels of wetting and drying (W&D) cycles, and then shear strength was measured. The splash erosion rate was measured at three levels of water status: air-dry, plastic limit (PL), and liquid limit (LL). The highest values of splash erosion were observed in the samples without the W&D cycle, and after applying the W&D cycles, splash erosion decreased. Moreover, splash erosion was higher in the air-dry and LL groups. Splash erosion decreased with increased clay content...

Journal of Arid Land, 2021

Investigating the relationships between vegetation dynamic and edaphic factors provide management... more Investigating the relationships between vegetation dynamic and edaphic factors provide management insights into factors affecting the growth and establishment of plant species and vegetation communities in saline areas. The aim of this study was to assess the spatial variability of various vegetation communities in relation to edaphic factors in the Great Salt Desert, central Iran. Fifteen vegetation communities were identified using the physiognomy-floristic method. Coverage and density of vegetation communities were determined using the transect plot method. Forty soil samples were collected from major horizons of fifteen profiles in vegetation communities, and analyzed in terms of following soil physical and chemical characteristics: soil texture, soluble Na + concentration, sodium adsorption ratio (SAR), electrical conductivity (EC), pH, organic matter content, soluble Mg 2+ and Ca 2+ concentrations, carbonate and gypsum contents, and spontaneously-and mechanically-dispersible clay contents. Redundancy analysis was used to investigate the relationships between vegetation dynamic and edaphic factors. The generalized linear method (GLM) was used to find the plant species response curves against edaphic factors. Results showed that plant species responded differently to edaphic factors, in which soluble sodium concentration, EC, SAR, gypsum content and soil texture were identified as the most discriminative edaphic factors. The studied plant species were also found to have different ecological requirements and tolerance to edaphic factors, in which Tamarix aphylla and Halocnemum strobilaceum were identified as the most salt-resistant species in the region. Furthermore, the presence of Artemisia sieberi was highly related to soil sand and gypsum contents. The results implied that exploring the plant species response curves against edaphic factors can assist managers to lay out more appropriate restoration plans in similar arid areas.

Cropping systems and managements can affect the water movement and solute transport through modif... more Cropping systems and managements can affect the water movement and solute transport through modification of soil structure. Our aim in this study was to investigate two soil textures and two crop managements combination effects on Lithium and Bromide transport under unsaturated flow conditions. The experiments were performed on 32 undisturbed soil columns (16 cm diam; 25cm deep) representing two soil series: structured clay loam and unstructured sandy loam which had been cropped with either wheat or alfalfa for 4 years. The steady state flow condition established using tap water prior to performing a pulse of 0.005 M LiBr solution on the surface of columns. Leaching monitored up to four pore volumes for each column. The Brand Li+ concentrations as tracer were measured in the effluent using bromide selective electrode and flame photometer respectively. Breakthrough curves for leached Brand Li+ in the soil columns exhibited an early higher concentration of both tracers indicating the preferential flow effect, in such that Br-concentration in term of magnitude was more than Li+. Both Brand Li+ concentration decreased with time and converged at low levels suggesting that soil macropores were blocked and leached was then transported in both soils via matrix flow. Clay loam under alfalfa showed higher Br and Li concentration levels comparing with sand loam under wheat crop production. In the soil under alfalfa structural cracks, root channels and wormholes were the cause of higher leached concentration for both tracers in compression with the soil under wheat. Theses results suggest that the preferential flow were more important in the soil under alfalfa than under wheat.

$Research paper thumbnail of Spatial prediction of soil aggregate stability and soil organic carbon in aggregate fractions using machine learning algorithms and environmental variables$

Journal of Arid Land, 2020

Scarce and scattered precipitation in arid regions is detrimental for newly planted seedlings. It... more Scarce and scattered precipitation in arid regions is detrimental for newly planted seedlings. It is essential to provide required water storage for seedlings in restoration projects in the first year of their establishment. The subsurface irrigation can be much more effective than the surface irrigation because of the regulation of water availability and reduction in water evaporation. We studied the effect of surface and subsurface irrigation methods on the growth and survival of four common tree species including heaven tree (Ailanthus altissima (Mill.) Swingle), China berry (Melia azedarach L.), white mulberry (Morus alba L.), and black locust (Robinia pseudoacacia L.) by installing underground clay reservoirs with different permeabilities in Isfahan City, Iran. Different amounts of animal manure and wheat straw were mixed with clay fraction and cooked in a pottery kiln at 900°C to produce reservoirs with different permeabilities. The experimental treatments consisting of irrigation and tree species were considered with a factorial arrangement in a completely randomized design with three replications in 2016 and 2017. Leaf water potential of seedlings, which is indirectly related to drought resistance, was measured by a portable pressure chamber. The results showed that saplings height, basal diameter, number of leaves, chlorophyll content and stomatal conductance were significantly (P<0.05) higher in the subsurface irrigation with low permeability than in the surface irrigation, but the number of branches of the studied species were not significantly (P>0.05) affected by the irrigation methods and different permeabilities of clay reservoirs. The clay reservoirs with low and medium permeabilities constantly provide better conditions for plant growth, and water with lower pressure and longer time intervals to the plant roots as compared with the reservoirs with high permeability. Analysis of variance of the data showed that year and interaction between year and permeability of reservoir had significant effects (P<0.05) on all growth parameters, except for the chlorophyll content. In addition, the highest percentage of survival was 100% associated with the subsurface irrigation and the control treatment had the lowest survival percentages of 60%, 70%, 80% and 100% for M. alba, M. azedarach, A. altissima and R. pseudoacacia, respectively. Finally, the values of leaf water potential showed that R. pseudoacacia was the most drought resistant species.

Journal of Water and Soil Science, 2019

Geoderma, 2016

This study was conducted to derive the relationships of soil shrinkage parameters and indices wit... more This study was conducted to derive the relationships of soil shrinkage parameters and indices with soil and environmental variables in calcareous soils. Ninety nine undisturbed clods were collected from surface soils in hilly regions of Cherlgerd, western Iran. Soil shrinkage curve was measured based on Archimedes' principle, by covering the clods with an acrylic resin. The shrinkage curve data were modeled using Peng and Horn (2005) model. The model's fitting parameters and several shrinkage indices (i.e. relative void ratio changes, mean slopes at various shrinkage zones, coefficient of linear extensibility, and total and relative shrinkage capacities) were predicted using multiple linear regression models by including soil properties (pedotransfer functions, PTFs) and by combination of soil properties and environmental variables (soil spatial prediction functions, SSPFs) as inputs. The results showed that, on average, the structural, proportional, residual and zero shrinkage zones comprised 17.2, 66.2, 15.2 and 1.4% of total shrinkage for the studied soils. The shrinkage capacity (ShC) and relative shrinkage capacity (Δe total-rel) varied, respectively, in the ranges 0.204-0.641 and 0.288-0.589 in the studied soils. While clay fraction increased the ShC and Δe total-rel , organic matter had a diminishing effect on the Δe total-rel. An extended structural zone was observed in fine-textured soils, presumably due to greater aggregation. Volume change in the structural shrinkage zone was greater in weakly-structured calcareous soils because carbonates would minimize resistance of aggregates against the shrinkage forces. PTFs could explain 12-48% of variability of the model's parameters, and the inclusion of topographic attributes (i.e. SSPFs) significantly increased R 2 values. Developed PTFs could explain 11-41% of variability of the shrinkage indices. The particle size fractions and relative bulk density were identified as most important soil properties for the prediction of shrinkage indices. Overall, the use of SSPFs by including topographic attributes such as dispersal area, elevation, surface curvature and plan curvature and normalized difference vegetation index (NDVI) could improve the performance of the prediction functions for soil shrinkage indices.

Journal of Water and Soil Science, 2015

Petroleum pollution is an important environmental issue in most countries especially those with a... more Petroleum pollution is an important environmental issue in most countries especially those with an oil industry. To study the effect of petroleum pollution on soil water repellency and its relation to soil structural stability, this study was conducted in Bakhtiardasht area, Isfahan. Polluted and adjacent non-polluted locations were selected to be representative in the green space around the Isfahan Oil Refinery. Soil water repellency was assessed using water drop penetration time (WDPT) in the polluted locations. Soil samples with the least aggregate disturbance were collected and their physical and chemical properties were measured. Soil structural stability was evaluated using the wet-sieving method and mechanically dispersible clay (MDC); structural stability indices of mean weight diameter (MWD) and geometric weight diameter (GMD) of aggregates and MDC were then calculated. Results showed that the positive effect of petroleum pollution on the MWD and GMD was significant. Negative impact of petroleum pollution on MDC was also significant. Increment of total petroleum hydrocarbons (TPHs) increased soil water repellency. A positive correlation was observed between water repellency and GMD in the soil. Although greater soil water repellency increased MWD and GMD and decreased MDC in the polluted locations compared with control locations, the diminished water retention of polluted soil created an unfavorable condition for the green space in the area.

Iranian Journal of Applied Ecology, 2016

In this study, raw and treated wastewaters were used for potato cultivation in lysimeters. Five i... more In this study, raw and treated wastewaters were used for potato cultivation in lysimeters. Five irrigation water treatments were included as: raw wastewater, treated wastewater, fresh water, a combination of 50% raw wastewater and 50% fresh water and a combination of 50% treated wastewater and 50% fresh water. The experiments were run within greenhouse during a period of four months. After construction and preparation of the lysimeters, they were filled with a twolayered soil. The textures of the upper and lower soil layers were sandy loam and sandy clay loam, respectively. In order to create the structure and conditions of the natural soil and develope macropores and preferential pathways, lysimeters were irrigated systematically each week during a period of five months before plantation. A total of eight irrigation programs with an interval of eleven-days were applied during the growth season. Unsaturated water infiltration into the soil was measured using a disk infiltrometer at the beginning and at the end of growth season. In order to evaluate the irrigation effects on soil physical properties, DISC Software (numerical) and Wooding (analytical) methods were employed to analyze the infiltration data. The results of saturated hydraulic conductivity were compared with direct measurements of the constant-head method, in which the numerical method (DISC software) was identified as the best method. The results showed that in all treatments, the saturated hydraulic conductivity and steady-state infiltration rate at matric suctions 5 and 10 cm increased after irrigations when compared with the initial values. Result also indicated that the unsaturated hydraulic conductivity and steady-state infiltration rate increased significantly in the wastewater treatments compared to the fresh water. Also, the maximum values of the steady-state infiltration rate and saturated hydraulic conductivity were observed in the raw wastewater and the combination of treated wastewater and fresh water treatments. The minimum value also belonged to fresh water treatment. Moreover, the highest changes in θ s, α VG and n VG were recorded in the combined fresh water-treated wastewater treatment. The lowest variations of these parameters (except θ s) were observed in fresh water treatment.

Soil Use and Management, 2013

This study was conducted to investigate the impact of land use (dryland farming, grassland and ir... more This study was conducted to investigate the impact of land use (dryland farming, grassland and irrigated farming) on bulk density, (ρb) and relative bulk density (ρb‐rel), and to study the relationships between ρb and ρb‐rel, respectively, and soil organic matter content (OM) and soil texture at 100 locations in calcareous soils of central Iran. The ρb–rel was expressed as the ratio of ρb to a reference bulk density, ρbef. By considering ρb‐ref an inherent soil property that is dependent on soil texture but not on OM, the combined effects of OM due to land use and compaction (due to agricultural machinery) on the degree of compactness could be explored. Multiple linear regression was used to derive pedotransfer functions for predicting ρb and ρb‐rel. It was found that ρb‐rel is strongly affected by OM, and a strong correlation was obtained between ρb‐rel and the ratio of OM to clay content. The predictive performance of the multiple regression models was poorest for irrigated farmin...

Journal of Terramechanics, 2007

Compaction is an important component of soil degradation. In this regard, the pre-compaction stre... more Compaction is an important component of soil degradation. In this regard, the pre-compaction stress (r pc) concept is considered useful in mechanized agriculture nowadays. When the external forces exceed the internal strength (r pc) of soil, soil structure and soil physical quality will deteriorate. This concept was introduced at first for confined consolidation of non-structured, homogenized and saturated subsoils in civil engineering, though it is also suitable for agricultural conditions where the topsoil and subsoil are considered and both are often structured, heterogeneous and unsaturated. The best method for predicting r pc is by the plate sinkage test (PST) in the field, but it is expensive and time-consuming. This study was conducted to find an alternative laboratory method besides the confined compaction test (CCT) for predicting r pc. The CCT may not be a good method, especially at higher water contents, and for soils with low organic matter content, because of low sharpness of the critical region on the stress-strain curves. The study was performed on five soil types with a range of soil textures and organic matter content from central Iran using three loading types and three pF (i.e. Log [soil matric suction in cm]) values of 2.3, 2.7 and 2.9 with two replicates. Loading types consisted of CCT, the semi-confined compaction test (SCCT) and the kneading compaction test (KCT) at three maximum (or pre-compaction) stresses of 200, 400 and 600 kPa. The experiment was a completely randomized factorial design. The aim was to determine how accurately each loading type test could predict r pc of soil pre-compacted by one of the other methods. The applied combinations of CCT-SCCT, SCCT-CCT and KCT-CCT mean that the soil was pre-compacted by the first loading type and evaluated by the second one. The results showed that r pc and the sharpness of the r pc region were significantly affected by loading types as well as the soil conditions. The sharpest r pc region was observed in SCCT and the least sharp in CCT with the overall order being CCT-SCCT > SCCT-CCT > KCT-CCT. The sharpness of the r pc region was reduced for the soil samples with higher water content and coarser texture. Regardless of the soil and loading conditions, the prediction by SCCT was consistently more accurate than by CCT. The prediction of r pc by SCCT was more precise in comparison with CCT especially at higher stresses and soil water contents. However, the prediction of r pc by SCCT was very accurate at pF values of 2.7 and 2.9, and with low r pc values, when compared with the actual values of the r pc. For the clay soil at a pF value of 2.3, no pre-compaction region (i.e. zero r pc) could be determined by CCT at a maximum axial stress of 600 kPa. This was because of the incompressibility of soil water at this near-saturated soil condition at high stress. However, the sharpness of the critical region in SCCT was high enough to predict r pc satisfactorily. There was no significant difference between the combinations of SCCT-CCT and KCT-CCT in predicting r pc. The SCCT is a compromise method that lies between CCT and PST. SCCT has the advantage of using a limited and definite soil volume that can be modeled as a soil element. Marginal effects of disturbance caused by coring/sampling as well as pre-test sample preparation seem to have minor effects on the stress-strain curve determined by SCCT in comparison with CCT. Moreover, the soil volume needed for this test is the same as for CCT.

Journal of Environmental Management, 2009

Organic wastes are considered to be a source for the potentially pathogenic microorganisms found ... more Organic wastes are considered to be a source for the potentially pathogenic microorganisms found in surface and sub-surface water resources. Following their release from the organic waste matrix, bacteria often infiltrate into soil and may be transported to significant depths contaminating aquifers. We investigated the influence of soil texture and structure and most importantly the organic waste properties on the transport and filtration coefficients of Escherichia coli and total bacteria in undisturbed soil columns. Intact soil columns (diameter 16 cm and height 25 cm) were collected from two soils: sandy clay loam (SCL) and loamy sand (LS) in Hamadan, western Iran. The cores were amended with cow manure, poultry manure and sewage sludge at a rate of 10 Mg ha À1 (dry basis). The amended soil cores were leached at a steady-state flux of 4.8 cm h À1 (i.e. 0.12 of saturated hydraulic conductivity of the SCL) to a total volume of up to 4 times the pore volume of the columns. The influent (C 0) and effluent (C) were sampled at similar time intervals during the experiments and bacterial concentrations were measured by the plate count method. Cumulative numbers of the leached bacteria, filtration coefficient (l f), and relative adsorption index (S R) were calculated. The preferential pathways and stable structure of the SCL facilitated the rapid transport and early appearance of the bacteria in the effluent. The LS filtered more bacteria when compared with the SCL. The effluent contamination of poultry manure-treated columns was greater than the cow manure-and sewage sludge-treated ones. The difference between cow manure and sewage sludge was negligible. The l f and S R values for E. coli and total bacteria were greater in the LS than in the SCL. This indicates a predominant role for the physical pore-obstruction filtration mechanisms as present in the poorly structured LS vs. the retention at adsorptive sites (chemical filtration) more likely in the better structured SCL. While the results confirmed the significant role of soil structure and preferential (macroporous) pathways, manure type was proven to have a major role in determining the maximum penetration risk of bacteria by governing filtration of bacteria. Thus while the numbers of bacteria in waste may be of significance for shallow aquifers, the type of waste may determine the risk for microbial contamination of deep aquifers.