Showing 32 results for Najafi
M. Najafi-Ghiri,
Volume 20, Issue 77 (Fall 2016)
Abstract
The status of soil K forms and its relationship with K content in wheat grain at harvest period may be important for nutrient fertility management. For this purpose, 40 surface (0-20 cm) and subsurface (20-40 cm) soil samples and also grain samples from wheat fields of Darab region were randomly sampled in 2014. Then physicochemical properties of the soils and the contents of soluble, exchangeable and non-exchangeable K and contents of K in wheat grains were determined. Results indicated that content of soluble, exchangeable and non-exchangeable K in the studied soils ranged 15-70, 91-443 and 396-1182 mg kg-1, respectively. Significant relationships were obtained between soil K forms and clay, calcium carbonate and CEC. Although it is expected that content of easily available K (soluble and exchangeable K) was low at late stage of wheat growth, most soils had sufficient K content. The positive and significant relationship among different K forms was indicative of the K forms equilibration at the time of wheat harvesting. Although there is not a relationship between K content in wheat grain and soil K forms, it was shown that K content of wheat grain was correlated with soil exchangeable K and clay content in fine-textured soils (clay > 30%). It means that ammonium acetate may be a suitable extractant for estimation of soil K status and plant available K of heavy-textured soils in the studied region.
K. Asgari, S. H. Tabatabaei, P. Najafi, Sh. Kiani,
Volume 20, Issue 78 (Winter 2017)
Abstract
Constant use of treated wastewater (TWW) for irrigation over long periods may cause buildup of heavy metals up to toxic levels for plants, animals, and entails environmental hazards in different aspects. The aim of this study was to assess the effect of using a deep emitter installation on lowering the potential heavy metal accumulation in soil and wheat grain, and health risk under drip irrigation with treated municipal wastewater. A field experiment was conducted according to a split block design with two treatments (fresh and wastewater) and three sub treatments (0, 15 and 30 cm depth of emitters) in four replicates in Esfahan, Iran. Soil samples were collected before planting (initial value) and after harvesting (final value) in each year. Elemental concentrations (Cu, Zn, Cd, Pb, Cr, and Ni) in soil and grain were determined using an atomic absorption spectrophotometer. A pollution load index (PLI) showed that there was not substantial buildup of heavy metals in the wastewater-irrigated soils compared to the freshwater-irrigated soils. Cu, Pb, Cr and Zn concentrations in wheat grain were within permissible EPA limits, but concentrations of Cr was above the safe limits of EPA. In addition, concentrations of Ni in wheat grain were several folds higher than EPA standards. A health risk index (HRI) which is usually adopted to assess the health risk to hazard materials in foods showed values higher than 1 for Cd and Cu, whereas children might also be exposed to health risk of Cd, Cu and Cr. Based on aforementioned results, it can be concluded that the depth of emitter in drip irrigation does not play a significant role in the accumulation of heavy metals from TWW in our sandy loam soil.
S. Moradnia, R. Naderi, M. Najafi,
Volume 21, Issue 2 (Summer 2017)
Abstract
In order to investigate the persistence of organic amendments, nitrogen and zinc effects on soil characteristics in rapeseed-wheat rotation, a factor analysis was conducted in a complete random design with three replications in two consecutive years in a greenhouse. Treatments in the first year consisted of N fertilizer, municipal waste compost, vermicompost, sheep manure. The control consisted of zinc and two rapeseed cultivars. In the second year of the experiment, two cultivars of durum wheat were sown in the same pots as the first year of the experiment. Results showed that two years after application of cattle manure, a significant increase in soil electrical conductivity (41.81 %), available K (59.45 %) and available Mn (79.82 %) compared to the control were found. Saturated soil moisture (48.57%), total N (94.66 %), available Fe (46.49 %) and available Cu (47.51 %) significantly increased by municipal waste compost compared to the control. Also, Zinc had a significant effect on soil total N (0.28 %), available K (218.4 mg/kg) and available Mn (12.89 mg/kg). Generally, the results showed that application of organic amendments can change many soil characteristics which some of their impacts might last for next upcoming years. Therefore, it is necessary to monitor the soil characteristics and nutrients availability of the fields that were treated with organic amendments in the years after application.
C. Tofighi, R. A. Khavari-Nejad, F. Najafi, Kh. Razavi, F. Rejali,
Volume 22, Issue 2 (Summer 2018)
Abstract
Salinity adversely affects crops metabolism and yield. The present work was conducted to evaluate the singular and interaction influences of Arbuscular mycorrhizal (AM) fungi and brassinolide, as an active group of (brassinosteroids) BRs, on some physiological parameters of wheat plants to cope with salt stress14-day old mycorrhizal (Glomus mosseae) and non- mycorrhizal wheat (Triticum aestivum L.). Plants were foliar sprayed with 0 and 5 µM epibrassinolide 3 times once every two days. Then, each group was treated with 0 and 150 mM NaCl once every 3 days for 10 days. After salt treatment, some plants were harvested to estimate the leaf reducing sugar and glycine betaine contents. After the final growth, all wheat plants were harvested to measure some yield parameters. Synergistic influence of brassinolide and AM fungi was observed in protein and 1000-grain weight. It seemed that this was rooted in the increased accumulation of reducing sugars and glycine betaine, both helping to maintain osmotic potential in cells under high salinity in soil.
R. Darabi Kandlaji, Shahin Oustan, Nasser Aliasgharzad, N. Najafi,
Volume 22, Issue 3 (Fall 2018)
Abstract
Nitrification is one of the most active biological processes in the soils receiving ammonium nitrogen. The rate of this process is under the influence of several factors and their interactions. In this study, the effects of ammonium concentration and moisture content on the extent of nitrification in two soil samples named A (Loam) and B (Clay loam), which had been taken, respectively, from Marand and Ahar areas, were investigated. A two-week factorial incubation experiment (25±0.5°C) was conducted in a completely randomized design with three replications. Factors were urea nitrogen at five levels (0, 50, 100, 200 and 400 mg N kg-1), moisture content at three levels (0.55FC-0.60FC, 0.75FC-0.80FC and 0.95FC-FC) and two soil types (A and B). At the end of the experiment, concentrations of ammonium and nitrate as well as the values of pH and EC were determined. Based on the results, average nitrification at 0.55FC-0.60FC was 22 percent lower than that at 0.95FC-FC and no significant difference was observed between 0.75FC-0.80FC and 0.95FC-FC. Nitrification at the treatment of 400 mg N kg-1and 0.55FC-0.60FC was decreased considerably and 25 percent of the added ammonium was accumulated. The average ammonium concentrations did not significantly vary among the levels of 50, 100 and 200 mg N kg-1, but these concentrations were significantly lower than those of 400 mg N kg-1. Moreover, EC and pH values of the soils were significantly increased and decreased in response to the nitrification (0.54 dS m-1 and 0.59 at the application level of 200 mg N kg-1, respectively). On average, the results showed higher nitrification (40.3 mg N kg-1) in the soil A (Loam texture) than the soil B (Clay loam).
M. Najafi-Ghiri, Y. Kiassi, F. Khademi, A. R. Mahmoodi, H. R. Boostani, Dr M. Mokarram, M. J. Gholami,
Volume 22, Issue 3 (Fall 2018)
Abstract
Little information is available regarding the effect of road on the adjacent vegetation and soil. The current investigation was done to study the effect of Darab-Bandar Abbas road on vegetation, soil properties and nutrient availability of the adjacent soils. For this purpose, eighteen soil samples in three different regions from the roadside and the adjacent land (50m from the road edge) were collected and the vegetation type and density were determined. Soil properties and the availability of N, P, K, Fe, Mn, Zn and Cu were also determined. Roadside soil had more organic matter and sand contents and less clay content and pH in comparison to the adjacent lands. The mean contents of N, Fe, Zn and Cu available in the roadside soils were 0.13%, 4.2, 3.2 and 0.7 mg kg-1, respectively; these were significantly more than those of the adjacent lands (0.06%, 2.8, 0.6 and 0.3 mg kg-1, respectively). Vegetation of roadside was more varied, consisting of Artemisia sieberi and Astragalus fasciculifolius. Vegetation cover in the roadside (13.8%) was significantly more than that of the adjacent lands (8.5%). Generally, it could be concluded that roadside soils had a suitable moisture condition and fertility for the vegetation development and this could be considered in the soil conservation management of the roadside soils.
M. J. Asadi, S. Shabanlou, M. Najarchi, M. M. Najafizadeh,
Volume 23, Issue 3 (Fall 2019)
Abstract
In this study, the discharge coefficient of the circular side orifices was predicted using a new hybrid method. Combinations made in this study were divided into two sections: 1) the combination of two algorithms including Particle Swarm Optimization (PSO) and Genetic Algorithm (GA) and providing the PSOGA algorithm 2) using the PSOGA algorithm in order to optimize the Adaptive Neuro Fuzzy Inference Systems (ANFIS) network and providing the ANFIS-PSOGA method. Next, by identifying the parameters affecting on the discharge coefficient of the circular side orifices, 11 different combinations were provided. Then, the sensitivity analysis conducted by ANFIS showed that the Froude number and the ratio of the flow depth to the orifice diameter (Ym/D) were identified as the most effective parameters in modeling the discharge coefficient. Also, the best combination including the Froude number (Fr), the ratio of the main channel width to the side orifice diameter (B/D), the ratio of the orifice crest height to its diameter (W/D) and the ratio of the flow depth to the orifice diameter (Ym/D) for estimating the discharge coefficient was introduced. For this model, the values of Mean Absolute Percentage Error (MAPE), Root Mean Square Error (RMSE) and correlation coefficient (R) were obtained 0.021, 0.020 and 0.871, respectively. Additionally, the performance of the ANFIS-PSOGA method was compared with the ANFIS-PSO and ANFIS methods. The results showed that the ANFIS-PSOGA method for predicting the discharge coefficient was the superior model
M. Najafi-Ghiri, H.r. Boostani, A. R. Mahmoodi, F. Dehghanpoor, M. Besh,
Volume 23, Issue 4 (winter 2020)
Abstract
Astragalus fasciculifolius is one of the most distributed plant species in the arid and semiarid regions of southern Iran. It may be well grown on roadside. This investigation was carried out to study the effect of road and its traffic intensity on the soil physicochemical properties and plant nutrients availability of roadside and to monitor the concentration of nutrients in the aerial parts of Astragalus fasciculifolius. Thirty soil and plant samples from roadside and 100 m distance from road were randomly collected and some physicochemical soil properties and nutrients availability were determined. Concentrations of the nutrients in the aerial parts of the plants were also determined. The results indicated that roadside soils had more sand and calcium carbonate equivalent than the adjacent lands. Soils of the main roadside had less K and more Fe, Mn, Zn and Cu than the adjacent lands; this difference in local road was observed only for Fe and Cu. Nutrients concentration in the aerial parts of the plants was affected by road, and P, K, Mn and Zn showed significant increases in the roadside plants. Concentrations of P, Fe, Zn and Cu in plants grown in main roadside and concentrations of Fe and Zn in plants grown in the local roadside were correlated with their contents in the soils. The effect of roads on soil properties change and nutrients availability may be related to the addition of road bed and emission of vehicles. Generally, it could be concluded that roadside soils had more suitable water and nutrition conditions for the growth of Astragalus fasciculifolius, as compared to the soils of the adjacent lands.
S. Rezapour, P. Najafi, B. Atashpaz,
Volume 24, Issue 2 (Summer 2020)
Abstract
In the present study, six soil profiles belonging to five soil types were dug, described and sampled. Soil samples were analyzed for the determination of different physicochemical properties and total and DTPA-extractable iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), lead (Pb), and cadmium (Cd). Considering the variability of pH and calcium carbonate equivalent, the examined soils were alkaline and calcareous. A considerable change in the values of the DTPA fraction of Fe (1.4-25.8 mg/kg), Zn (0.01-3.3 mg/kg), Cu (0.32- 6.2 mg/kg), Mn (1-11.8 mg/kg), Cd (0.05- 0.12 mg/kg) and Pb (0.22- 2.56 mg/kg) as well as in the total fraction of Fe (10.6-20.6 g/kg), Zn (35- 67.5 mg/kg), Cu (9 to 26.40 mg/kg), Mn (262- 588.8 mg/kg), Cd (0.5- 1.75 mg/kg) and Pb (17- 31.3 mg/kg) was observed in different soils. The content and pattern of both DTPA and total fraction of the metal were varied among the soil types, which could be related to several processes such as the diversity of weathering rate, geomorphologic condition, soil formation process, different physicochemical properties of soils, and the inputs of different agrochemical compounds. The concentration of both DTPA and total fraction of the metal were in the acceptable maximum level in the majority of the soil samples.
A. Jamal, M. Najarchi, M. M. Najafi Zadeh,
Volume 24, Issue 3 (Fall 2020)
Abstract
Surge tanks and air chambers are the most useful solution to deal with water hammer in water transmission systems (WTS). The optimal design of these protective devices can be effective in reducing the costs of constructing and operating a water transmission system. In this article, some software with the capability of simulating and optimizing these protective equipment is presented. To simulate the behavior of the system in the transient condition, the characteristic method was used. To optimize the number, dimensions and location of the surge tanks and air chambers, the genetic algorithm was employed. Constraints of the problem included the control of negative and positive pressures within the permissible range to prevent the cavitation and water hammer. To test the performance of simulation and optimization models, a well-known water transmission system in the previous research was selected as a case study. The results indicated that the critical heads were damped to a safer and allowable range; also, the total cost of the surge tanks and air chambers was reduced by 17% by the proposed method.
S. Yaghobi, Ch.b. Komaki, M. Hosseinalizadeh, A. Najafinejad, H.r. Pourghasemi, M. Faramarzi,
Volume 27, Issue 1 (Spring 2023)
Abstract
Frequency analysis of daily rainfall or return period of rainfall and flooding events is very important considering the behavioral complexity in water resources management; because ignoring it can lead to urban destructive floods. In the present research, three distribution functions of Pearson, Beta, and Gamma were compared to investigate and select the most appropriate distribution function for the precipitation data acquired from meteorology stations and CHIRPS satellite in seven stations in the watershed of Bustan Dam. Statistical analyses showed that satellite data were ineffective to estimate daily precipitation due to high errors in RMSE, MAD, and NASH. Meteorological data were used to spot the best distribution. Google Earth Engine and Python programming language were used. Then, the selected distribution function was used to determine the maximum daily rainfall, frequency probability, and return period of 2, 10, 50, 100, and 200 years. The results of the goodness of fit test, Error Sum of Squares, Bayesian Information Criterion, Akaike Information Criteria well as Kullback-Leibler Divergence showed that in five stations of Kalaleh, Qarnaq, Golestan National Park, Golestan Dam, and Glidagh, the Pearson function is the most suitable distribution function. Also, in the other two stations (Gonbad and Tamar), the Beta function was recognized as a suitable function. However, Gamma distribution in the study area is not efficient. So, it can be concluded that heavy and irregular rainfall can be effective in choosing the best distribution function at each station. Therefore, it is recommended to consider the maximum possible rainfall and as a result of the possible occurrence of floods with principled and accurate management to prevent human and financial losses in susceptible areas, especially in the study area.
M. Kashi, S. Alizadeh Ajirlo, N. Najafi,
Volume 28, Issue 1 (Spring 2024)
Abstract
The reduction of water resources due to the issue of global climate change and population growth is one of the most critical issues facing the designers and planners of the development of green spaces in cities. Against these challenges, there is an urgent need to improve the efficiency of water consumption and chain use of water resources with suitable options. Due to the significant volume of urban wastewater Effluent, its reuse in green space irrigation is important from the point of view of water resource management from an ecological and economic point of view. The effect of the Parand city wastewater treatment plant on the chemical properties of soil under the cultivation of three types of cover crops (Frankinia (FR), Festuca (FE), Dichondra (DI)) in a bed with sandy loam soil is investigated. This study was conducted as a factorial experiment based on a completely randomized design using mixing of water and Effluent at 4 levels with irrigation treatments of zero (control), 50, 75, and 100% compared to fresh water and 3 replications, and then the soil chemistry characteristics such as pH, EC, OC, Na, Cl, Ca, and Mg were evaluated. The results obtained from the soil chemical analysis parameters showed that the pH value decreased in all the treatments with effluent compared to the control, and this decrease was not significant in any treatment. The values of EC and Cl have increased in all plants, and these values were significant in the FR100 treatments with an increase of about 195 and 561% compared to the control, and in the FE100 treatment with an increase of about 54 and 162%, respectively, at the 5% probability level. The amount of OC in the FR100 treatment was significant with an increase of about 41% compared to the control treatment, but in other plants, this ratio was not significant in any treatment. The maximum amount of Mg in the FR50 treatment was 30.27, which has a significant effect compared to other treatments. The amount of Na and Ca in the FR100 treatment was significant with an increase of about 343% and 130%, respectively, compared to the control treatment, while in FE and DI plants, this ratio was not significant in any treatment.
