Showing 13 results for Safari
A. M. Amini, R. Safari Shali,
Volume 6, Issue 2 (summer 2002)
Abstract
This manuscript shows the findings of a research that investigated the effects of trainings on the members and the employees of the poultry cooperatives in Tehran Province on the performance of these cooperatives. To analyze the data, 2, correlation coefficient, one way-analysis of variance, and Duncan Test were used. The results of the study showed a positive and statistically significant relationship between training of members and performance of cooperatives. The more the trainings were related to type of occupation or responsibility, the larger were the effects on the cooperative performance. Cooperatives with more specialized top managers, offered more training to their members. Compared to cooperatives with more training, the members had less participation in increasing their investment.
A. A. Safari Sinejani, G. Emtiazi, H. Shariatmadari,
Volume 6, Issue 3 (fall 2002)
Abstract
Soil organic matter and clay minerals adsorb and immobilize extracellular enzymes of microorganisms and increase soil enzymes stability. This study aims to clarify the relative importance of soil organic matter and clay minerals on the cellulolytic activities of soils. Fluca prepared cellulase was immobilized on some agricultural residues and clay minerals, avicel and a sample of soil. Immobilized exoglucanase and endoglucanase were assayed at different times. Activities of the immobilized enzymes were strikingly dependent on the kind of sorbent. After 20 days of storing in refrigerator at 4oC, the deactivation of immobilized enzymes on the organic substances (as avicel) was very low but deactivation of immobilized enzymes on the soil and clay minerals was relatively high. On the other hand, the activities of immobilized enzymes on the agricultural residues and avicel were significantly higher than the soil and clay minerals. So it may be concluded that a large part of cellulolytic activity of soil is related to immobilized enzymes on agricultural residues. Coating of the clay minerals, soil and avicel with 4 mmol of Al (OH) x per mg of them significantly increased their immobilization capacity and activities of immobilized enzymes. Activities of immobilized exoglucanase and endoglucanase on the Ca- homoionized soil and clay minerals were significantly higher than the K- homoionized soil and clay minerals. However, these effects may be related to the specific effects of cations on the method of enzyme assay or enzymes activities. These homoionizing-cations effects on the activity of immobilized enzymes on avicel were not significant.
M. R. Safari Motlagh, F. Padasht, Gh. Hedjaroude,
Volume 9, Issue 2 (summer 2005)
Abstract
The brown spot disease is one of the seed-borne diseases of rice, found in the all stages of its growth from nursery to farm. It causes qualitative and quantitative damage on rice. Therefore, some studies carried out on the different aspects of this disease and the reaction of some cultivars of rice against the pathogenic fungous agent of the diseases. To do so, 120 isolates, isolated from plant samples were collected from the 91 paddy fields in Guilan. To isolate the pathogenic fungous agent of the disease, the collected samples were cultured on PDA and filter paper. According to the results, the present isolation related to Bipolaris with the 3 species : Bipolaris oryzae (Ito & Kurib.) Drechsler ex Dastur Bipolaris victoriae Nelson Bipolaris sp. The total isolataes were consisted of 15% Bipolaris oryzae, 75% Bipolaris -victoriae and 10% Bipolaris sp. The study of pathogenicity of isolation in these three species was applied to Khazar rice in desicator. The symptoms created by these three species were different from necrotic spots to leaf death. The results indicated that not only the symptoms but also the virulence in these three species were different. The virulence in B. oryzae was more than B. sp and this was more than B. victoriae. To study the reaction of some cultivars of rices to the pathogenic fungous agent, 8 cultivars of rice: “ Bejar, Khazar, Sepeedroud, Domsephid, Hassan saraee, Binam, Neda, Nemat” respectively were used in the two stages of the plant growth, to leaf in the seedling stage and heading. The results indicated that in seedling stage there was no significant difference between these cultivars with respect to the amount of infection. And in heading stage, according to “Dunken” test (5%) they divided into the 3 groups: “Neda, Sepeedrud, Khazar and Binam” with the lowest amount of infection were in the first group, “Bejar, Domsephid and Hassan saraee” classified in the second group and “Nemat” was in the third one. But there was no significant difference between them according to the variance analysis table.
K. Rostami, M. R. Mosaddeghi, A. A. Mahboubi, A. A. Safari Sinegani ,
Volume 12, Issue 44 (summer 2008)
Abstract
Transport and filtering of pathogenic bacteria through porous media and groundwater resources are important and، therefore the effect of various factors on bacteria transport and filtering has been given a great attention nowadays. In this study، effects of calcium sulfate and carbonate on Psedomonas fluorescens filtration and filtering parameters were investigated in saturated sand columns under steady-state flow. The calcium carbonate levels included 0، 5، 10 and 20 %w/w and calcium sulfate levels consisted of 0، 5 and 10 % w/w which were thoroughly mixed with sand (0.15-0.25 mm). The experiment was considered factorial in completely randomized design with three replicates. The treated sands were poured into pyrex cylinders with length of 20 cm and diameter of 7 cm. Then، steady-state saturated flow with constant flux was applied to the columns. When the steady-state flow was established، the bacteria suspension with concentration of 106 CFU cm-3 (C0) was injected as step input into the columns. The leaching then was continued up to 5 times of pore volume (PV). The effluent concentration of the bacteria (C) was measured at 0.25 PV intervals. Then، the sand columns were divided into 0-5، 5-10، 10-15 and 15-20 cm layers in order to measure the filtered bacteria in each layer. The results showed that the effects of calcium carbonate on retaining of the bacteria in the 5-10 and 10-15 cm layers were significant at 1% level. It was significant at 5% for the 15-20 cm layer. The effect of calcium sulfate was also significant at 5% for the 10-15 cm and 15-20 cm layers. The interactive effects of treatments on bacteria adsorption was significant for the 5-10، 10-15 and 15-20 cm layers. The retained concentration profile and the filtration coefficient were significantly affected by the treatments، showing higher bacteria adsorption at lower depths and predominance of physical filtering. The results showed the high filtering capacity of carbonate and sulfate minerals which could ultimately reduce bacteria transport in saturated porous media towards groundwater resources.
M. B. Farhangi, M. R. Mosaddeghi, A. A. Safari Sinegani, A. A. Mahboubi,
Volume 16, Issue 59 (spring 2012)
Abstract
In agriculture, cow manures are used to enhance soil fertility and productivity. Escherichia coli is the most common fecal coliform in cow manure and considered as an index for microbial contamination of groundwater resources. The objective of this study was to investigate the transport of Escherichia coli (released from cow manure) through the field soil. Lysimeters (with internal diameter of 20.5 and height of 50 cm) were inserted into an in situ clay loam soil. Unsaturated soil water flow was controlled at an inlet matric potential of –5 cm using a tension infiltrometer. When the steady-state flow was established, air-dried fresh cow manure was applied on the lysimeters at a rate of 10 Mg ha-1 (dry basis) and the soil-manure leaching started. Soil solution was sampled at 1, 2, 4, 6, 12 and 24 h after leaching initiation using plastic samplers installed at depths of 20 and 40 cm. Concentrations of Escherichia coli in the soil solution (C) and the influent (C0) were measured using the plate count method. Impacts of soil depth, sampling time, and their interaction on C and C/C0 were significant (P<0.01). In all leaching times, relative adsorption index (SR) was lower when both soil layers were considered and the filtration increased with soil depth. When the concentration was corrected for the second layer (i.e. 20–40 cm), the SR values in this layer were considerable and greater than those in the first layer at 4 and 6 h. The influence of surface layer was substantial in bacterial filtration however, the preferential flows especially in the initial leaching times resulted in bacterial movement towards the second layer. Temperature drop reduced bacteria release from the manure, increased viscosity of the flowing water, and consequently diminished significantly the bacteria concentration in the soil solution at 24 h. Overall, it was found that similar to surface layer, subsurface layer might have great role in bacterial filtration due to its higher clay and carbonate contents
Y. Safari, I. Esfandiarpour Boroujeni,
Volume 17, Issue 65 (fall 2013)
Abstract
In order to study the precision of qualitative land suitability classification method for main irrigated crops (i.e. potato, sugar beet, wheat and alfalfa) in the Shahrekord plain, qualitative land suitability maps were obtained for all the studied crops according to representative pedon analysis using simple limitation method. In the next step, a regular grid sampling consisting of 100 sample points with a distance of 375 m was designed. Then all required analyses were done to recognize the suitability class of these sites for each land use. Finally, land suitability results for all the observation points in each map unit were compared with the results of its representative pedon. The results showed the average of measured compatibility between representative pedon and other observation points in each map unit in class and subclass levels was about 60 % and 38 %, respectively. Due to the generalization of representative pedon analyses to all unit area, the use of soil map units as land suitability units may lead to unsatisfactory results. Therefore, the use of representative pedon is not recommended in sustainable land management and precision agriculture. However, new techniques like geostatistics can be used to improve the conventional soil mapping methods.
I. Esfandiarpour Boroujeni, Y. Safari,
Volume 18, Issue 67 (Spring 2014)
Abstract
Comparison of the land suitability variations among the soil map units in viewpoint of pedodiversity indices may provide a good assessment of the soil mapping precision. The main objective of this study was to assess the significance of functional pedodiversity thorough two detailed map units for irrigated wheat and potato for class and subclass levels of suitability in the Faradonbeh plain, using Shannon and Simpson indices. First, soil samples at 35 and 47 sampling sites in the D and E map units, respectively, were collected from the depths of 0-25, 25-50, 50-75 and 75-100 cm. Then, the qualitative land suitability class and subclass of all sampling points for each studied land use, was evaluated based on simple limitation method. Although both indices showed higher values in the subclass level of suitability, but the average functional pedodiversity of the studied map units, indicate a significant difference (95% confidence level), just in this suitability level. It was observed that the significance of the pedodiversity indices is not influenced by the land use type or the analyzed diversity index. Hence, as a supplementary procedure to study the intra-unit variation of the soil maps, use of diversity indices may provide some worthwhile information
Gh. Vahabzadeh, A. Safari, M.h. Farhoudi, H.r. Abdollahi, H. Fathizad, Gh.r. Khosravi,
Volume 18, Issue 70 (winter 2015)
Abstract
In this research, sediment production and delivery amount by Darabkola forest roads was estimated using the SEDMODL model. To evaluate the model results, the sedimentation rate in the above roads was directly measured using rainfall simulator. Also, the paired t-test, BIAS, RE and RMSE were used to assess the results. The analysis showed that the rate of sediment production from study roads' surface using the SEDMODL model and direct measurement under the rainfall simulation were 420.97 and 341.19 tons per year, respectively, and rate of sediment delivered to the stream with sediment delivery ratios of 42% and 51%, respectively, was about 177.58 and 174.02 tons per year. Also, results of the statistical methods of BIAS, RE and RMSE for the aforesaid model were 0.04, 17.59 and 0.71, respectively, and at 95% confidence level, no significant difference was obtained between the observed and estimated data. Therefore, the aforesaid model has the appropriate accuracy and efficiency to estimate the sedimentation rate of the Darabkola forest roads. It was also found that from among the input parameters of model, longitudinal slope of road, precipitation and sediment delivery factors were the most influential factors in the sediment production and transport, respectively.
E. Esfandiary Ekhlas, M. Nael, J. Hamzei, A. A. Safari Sinegani, M. Sheklabadi,
Volume 22, Issue 2 (Summer 2018)
Abstract
Evaluation of the ecological sustainability of different cropping systems is crucial to achieve sustainable agriculture. This evaluation is accessible via soil quality assessment. Therefore, to study the mid-term effects of different conservation tillage systems (no tillage and minimum tillage) and cover cropping on the biological indicators of soil quality, a factorial experiment in a completely randomized block design was conducted in Dastjerd region (Hamedan). Three levels of tillage (NT: no tillage, MT: minimum tillage and CT: conventional tillage) and two levels of cover cropping (C1: Lathyrus sativus and C2: no cover crop) were applied for four consecutive years. Soil sampling was performed in the fourth year of experiment in two steps (1- before cover crop plantation, and 2- after harvesting main crop) with three replications. Most indices (total organic carbon, active carbon, basal respiration, phosphatase activity) were significantly affected by cover crop, tillage systems and sampling time, as the highest values were obtained in NT-C1 in time 2 and the lowest ones in CT-C2 in time 1. For instance, after four years application of treatments, the mean active carbon content was increased from 927 mg/kg in the conventional tillage + no cover crop to 1350 mg/kg in the conservation tillage systems + cover crop. Therefore, conservation tillage practices combined with Lathyrus sativus cover crop were shown to be the most appropriate management for soil quality maintenance and improvement.
Gh. Safarinejadi, M. Heidarnejad, A. Bordbar, M. H. Pourmohammadi, A. Kamanbedast,
Volume 23, Issue 4 (Special Issue of Flood and Soil Erosion, Winter 2019)
Abstract
The use of free launch jets in flip bucket structures with associated submerged ponds, in the appropriate geological, and topographic and hydraulic conditions, could have significant economic and safety benefits. In this research, the downstream scour phenomenon of a flip bucket jet was investigated in free conditions, as well as in the presence of a trapezoidal and triangular slot in the coastal manner with different layout intervals at flow rate of 9, with a total of 45 experiments. The results of this study showed that the presence of the slot had significant effects on the depth and range of scour, so that the fit bucket jet with alternate triangular slots reduced the scour by about 12.7%, as compared to the no slot mode. Moreover, the maximum scour depth occurred in the bucket mode with the alternate trapezoidal slots in the more favorable interval than the rest of the models. Then, the results were compared with several empirical formulas and Veronese A relation showed closer results to the actual values.
Z. Noori, M. A. Delavar, Y. Safari,
Volume 24, Issue 4 (Winter 2021)
Abstract
The present study was intended to improve the chemical properties of a saline-sodic soil using the individual application of alfalfa residue and two biochars produced from sugarcane bagasse and walnut shell, at the weighting ratio of 5%; their concomitant application with gypsum, aluminum sulfate and the mixture of these two chemical amendments was considered. The experiment was conducted in three replications using the factorial experiment in a completely randomized design. After four months of incubation, the soil samples were measured for their main chemical properties. The results showed that alfalfa residues were the most effective treatment to reduce the soil pH; so the concomitant application of this organic amendment with gypsum lowered the soil pH from 9.13 in the control (untreated soil) to 7.24. It was also observed that the addition of gypsum and/or aluminum sulfate to the soil led to the increase of the soil electrolyte concentration and consequently, the increase of soil electrical conductivity to three times greater than control, through an increase of ions, like calcium and sulfate in the soil solution. Increasing the soluble sodium concentration by replacing exchangeable sodium by other similar ions showed that the studied treatments enhanced the sodium adsorption ratio (SAR), which could be regulated by washing. Concomitant application of the walnut-shell biochar with gypsum had the most increasing effect on the soil SAR, enhancing it from 22.6 in the control to 54.3. Potassium was released from organic amendments, improving the soil general conditions; addition of chemical amendments elevated soil exchangeable potassium contents; however, the elevated soil available phosphorus contents were less influenced by chemical amendments application. As the conclusion, it seems that the positive impacts of the applied chemical and organic amendments would supplement each other; as a result, the concurrent use of both treatments not only improves the bad soil chemical properties, but also enhances the soil fertility.
S. Jamali, H. Banejad, A. Safarizadehsani, B. Hadi,
Volume 26, Issue 1 (Spring 2022)
Abstract
This research was conducted to study the effect of deficit irrigation and saline water on yield and yield components of Peppermint in the experimental research greenhouse of Ferdowsi University of Mashhad from 2018 to 2019. This research was performed as a factorial experiment based on the randomized complete design with three replications. In this research, irrigation levels consist of 4 levels (100 (I1), 80 (I2), 70 (I3), and 55 (I4) percent of FC) and saline water factors consist of 4 levels (0.9 (EC1), 1.9 (EC2), 2.5 (EC3), and 3.4 dSm-1 (EC4)). The result showed that a decrease of the water to 15, 30, and 45 percent have resulted in the reduction of shoot fresh weights (to 15.8, 28.4, and 30.1 percent), shoot dry weights (to 7.1, 11.5, and 11.5 percent), and root dry weights (to 4.6, 9.2, and 9.2 percent), respectively. Also, results showed that irrigation with EC2, EC3, and EC4 has resulted in a decrease in shoot fresh weights (to 12.7, 28.5, and 34.0 percent), shoot dry weights (to 3.6, 11.6, and 11.6 percent), and root dry weights (to 6.7, 12.4, and 14.6 percent), respectively. The result indicated that interaction effects of salinity and water stress decreased peppermint water productivity, as the highest and lowest peppermint water productivity with 3.54 and 2.06 Kgm-3 were in the EC1I4 and EC3I1 treatments, respectively. Results revoluted that maximum dry yield and peppermint water productivity were in the EC1I4, so this treatment was recommended for irrigation of peppermint.
S. Koohi, B. Bahmanabadi, Z. Partovi, F. Safari, M. Khajevand Sas, H. Ramezani Etedali, B. Ghiasi,
Volume 27, Issue 4 (Winter 2023)
Abstract
Water supply remains a significant challenge in arid and semi-arid regions, and in addressing this concern, unconventional water sources have gained prominence. Notably, the extraction of water from air humidity, classified as an unconventional water source has seen increased adoption. Diverse techniques have been developed to achieve this goal, with the utilization of mesh networks being particularly prevalent. Consequently, this study assesses the evaluation of the performance of the ERA5 dataset in the simulation of atmospheric variables that influence the ability to assess water harvesting from air humidity (including temperature, wind speed, and water vapor pressure). Also, the possibility of water harvesting from air humidity was investigated in Qazvin Province. The outcomes demonstrated the benefit of incorporating adjustment coefficients in estimating temperature and wind speed using the ERA5 dataset. Based on these findings, the northwestern and southern regions of the province (Kuhin and Takestan) exhibit notable potential during spring and summer for water harvesting from the atmosphere. The peak water harvesting for these stations in the summer is estimated at 10.2 and 9.7 l/day.m2, respectively. Using the ERA5 reanalysis dataset, the annual average potential for water harvesting in the stations was evaluated at 7.9 and 4.6 l/day.m2, respectively. Notably, the minimum water harvesting capacity during the summer season recorded in Qazvin is equal to 3.39 l/day.m2, which can be planned for use in irrigation requirements of green spaces, fields, or gardens.
