Showing 18 results for Rahmani
H.r. Rahmani, M. Kalbasi, S. Hajrasuliha,
Volume 4, Issue 4 (winter 2001)
Abstract
Soil as the third major component of our environment is exposed to different kinds of pollution. Lead has been recognized as a factor in environmental pollution. Pollution of soil and plants along the highways and roads by Pb from automobile exhaust gases has extensively been reported as the most important pollutant source in the environment. This research was carried out to determine the degree of soil pollution along the following highways: Rasht-Anzaly (Anzaly area), Kelachay-Ramsar (Ramsar area), Tehran-Karaj (Karaj area) and Isfahan-Tehran (Delijan area). In each location a transect of 100 meters long, perpendicular to the highway axis, was selected for sampling. Soil samples at different depths were taken from different distances from the highway and analysed for some physical and chemical characteristics and total Ph content by 5M HNO3 extraction.
Results indicated that the total Pb content of soil decreased exponentially with distance from the roadside. Total Pb content of soil decreased sharply with depth in all highways except in one area indicating that Pb was retained in the surface soil and that its movement down to the deep soil was slow. Total Pb content of soils was highly and directly related to the traffic volume.
M. Babashahi, Gh. Ghorbani, H. R. Rahmani,
Volume 8, Issue 3 (fall 2004)
Abstract
The purpose of this study was to evaluate nutritional status in Isfahan dairy herds and the relationship between milk urea nitrogen (MUN) and fertility in the first postpartum insemination. Blood and milk samples were collected from 170 and 290 Holstein cows from 9 dairy herds, respectively. Feed samples were also collected to quantify the relationship between MUN and protein and energy content of the ration. When simple linear regression was used, a close relationship was found to exist between blood and milk urea nitrogen. Regression equations indicated crude protein percentage and protein to energy ratio in the diet only explained 7 and 10 percent of milk urea nitrogen variations, respectively. The low correlation coefficient is probably due to incorrect nutritional management and variation in diet composition in different feeding days. Logistic regression was used to determine the relationship between MUN and fertility. A negative curvilinear relationship existed between MUN and rate of pregnancy at first insemination. Since cows with MUN concentrations of 16.5 to 19 mg/dl had a better chance for pregnancy than those having either below or above these values, it seems likely that pregnancy chances for those cows having this range of MUN concentration are 1.94 and 1.63 times more than cows with less than 14 mg/dl and between 14 - 16 mg/dl, respectively.
The results of this study indicated that although MUN is a useful tool for nutritional management of dairy cows, it is not suitable for monitoring reproductive performance.
M. Sepehri, N. Saleh Rastin, H. Asadi Rahmani, H. Alikhani,
Volume 10, Issue 1 (spring 2006)
Abstract
Heavy metals have deleterious the effects on nodulation and N2 fixation of Rhizobium- Legume symbiosis, due to their inhibitory effects on the growth and activity of both symbionts. This research has been undertaken to evaluate the effect of Cd tolerance of native rhizobial strains on diminution of the Cd detrimental effects on Sinorhizobium meliloti-alfalfa symbiosis. For this purpose, a greenhouse experiment was conducted based on Randomized Complete Block Design. The treatments in this experiment included: plants inoculation with 6 bacterial strains (sensitive, partially tolerant and tolerant to Cd), 5 levels of Cadmium (0, 2, 5, 10, 20 mg/kg soil) and non-inoculated control. In different levels of Cd, the effects of bacterial inoculation on root nodule number and total amount of nitrogen in plant shoot were compared. The results indicated that soil pollution by Cd even at 2 mg/kg had significant effect on symbiotic properties of rhizobial strains, and according to Cd tolerance of various strains, the mentioned effect was different. Decreasing effect of Cd concentration on root nodules and nitrogen concentration in plants that were inoculated with sensitive strains in comparison with plants inoculated with tolerant strains was 68.31% and 40.8%, respectively. In this research, R95m was introduced as the best strain because of its ability for nodulation and nitrogen fixation.
M. J. Agah, J. Pourreza, A. Samie, H. R. Rahmani,
Volume 10, Issue 2 (summer 2006)
Abstract
This experiment was carried out to determine the effects of different levels of (Kabuli) chickpea grains with different processing methods on the performance of broilers. In a factorial experiment with completely randomized design, 576 Rose broiler chicks were divided into 16 treatments with three replications of 12 chicks each. The first factor comprised three levels of chickpea (10, 20 and 30 percent) in ration, and the second factor five processing methods of chickpea (raw, cooked for 10 and 20 mins, and soaked for 24 and 48 hrs). Treatments included one control ration (without chickpea) and 15 experimental rations, all of which were isoenergetic and isonitrogenous. The experimental period lasted 8 weeks for the 1 to 56 day old chicks. Body weight gain, feed intake, feed conversion ratio were determined at three age periods of 7 to 21, 7 to 42 and 7 to 56 days. Carcass, abdominal fat, intestine and pancreas weight percentages to live weight were measured. Maximum body weight gain belonged to chickens fed on %30 chickpea grains soaked for 48h in age periods of 7 to 42 and 7 to 56 days, which was significantly different from control diet (P<0.05). The effect of chickpea grains levels and processing methods on chicken feed intake in age periods of 7 to 56 days was not significant. Interaction effects of chickpea levels with processing methods on feed conversion ratio in three age periods was not significant either. The effect of chickpea grains levels and processing methods on carcass, abdominal fat and intestine weight percentages to live weight were not significant except for the pancreas weight percentage (P<0.05). Therefore, it seems that chickpea grain is a suitable source of energy and protein in broiler diet (20% as raw or 30% as soaked for 48% h) when soyabean meals and corn grains are unavailable.
H.r. Rahmani, A.a. Gheisari, R. Taheri, A. Khodami, M. Toghiani,
Volume 12, Issue 43 (spring 2008)
Abstract
This experiment was conducted to evaluate the effects of 7 experimental diets (2 diets containing 100 and 200 mg vitamin E (VE)/kg and 5 diets containing 0, 0.5, 1, 1.5 and 2% green tea powder (GTP) ) on performance and breast and thigh meat oxidative stability of broiler chicks during different storage times. A total of 364 male broiler chicks were divided to 28 groups of 13 chicks each. Then every 4 groups were randomly allocated to one of experimental diets. During the experimental period (7-42 days of age) feed intake, weight gain and feed conversion of the experimental groups were measured. On day 42, 2 birds from each replicate (8 chicks per treatment) were weighed, slaughtered and their muscles of breast and thigh were minced and stored at 4ºC. Meat oxidative stability of the samples was determined on days 0, 6 and 9 of storage time using thiobarbituric acid test (TBA test). The results showed that addition of the VE and GTP to diets tended to significantly (P<0.05) reduce live body weight, weight gain, feed intake and abdominal fat accumulation and increase feed conversion ratio and pancreas size compared to control group. Increasing storage time from 0 to 6 and 9 d significantly (P< 0.05) increased TBA number. Lipid peroxidation and TBA values in thigh muscle were significantly (P<0.05) higher than breast muscle (1.46 vs. 0.359 mg Malonaldehyde/kg meat). Different dietary levels of GTP in diets did not have any significant effect on prevention of meat lipid peroxidation. In addition, the values of TBA in meat of the groups fed diets containing high levels of GTP significantly (P<0.05) increased in comparison to control group and those fed VE supplemented diets.
E. Rahmani, A. Khalili, A. Liaghat,
Volume 12, Issue 44 (summer 2008)
Abstract
The growing season climatic parameters, especially rainfall, play the main role to predict the yield production. Therefore, the main objective of this research was to find out some possible relations among meteorology parameters and drought indexes with the yield using classical statistical methods. To achieve the objective, ten meteorological parameters and twelve drought indexes were evaluated in terms of normality and their mutual influences. Then the correlation analysis between the barley yield and the climatic parameters and drought indexes was performed. The results of this study showed that among the drought indexes, Nguyen Index, Transeau Index, Rainfall Anomaly Index and Standardized Precipitation Index (SPI24) are more effective for prediction of barely yield. It was also found that the multivariate regression is better than the univariate regression models. Finally, all the obtained regression models were ranked based on statistical indexes(R,RMSE and MBE). This study showed that the multivariate regression model including wind speed, sunshine, temperature summation more than 10, precipitation and Nguyen index is the best model for prediction yield production in Miane. Average wind speed and Nguyen index were recognized to be the most effective parameters for yield production in the model.
S Shrifi, H Rahmani, M Motamedi,
Volume 13, Issue 47 (4-2009)
Abstract
In dairy cattle, the increase in milk yield has been accompanied by a more negative energy balance during early lactation and a decrease in fertility. The 167 amino acid protein product of the ob gene was named leptin (derived from the Greek term ‘leptos’ meaning thin). The leptin hormone, as a 16-kDa protein is synthesized mainly by adipose tissue and is involved in regulation of food intake, energy balance, fertility and immune function. The expression and secretion of leptin are correlated with body fat mass and are acutely affected by changes in food intake. The objective of this study was to investigate the fluctuations of leptin concentrations during late pregnancy and early lactation, the effect of parity and BCS on plasma leptin concentration, and to investigate its fluctuation effects on reproductive status. Blood samples of 54 Holstein cows were taken at a fixed time of the day after milking but before feeding, from 2 weeks before calving until 6 weeks after calving. BCS and plasma leptin concentration were measured at 2-wk intervals. Leptin concentrations were affected by parity. Primiparous cows and cows in first parity had higher leptin concentrations compared with multiparous cows (P<0.05). Leptin concentration was not different in late pregnancy and early lactation. BCS was negatively correlated with plasma leptin concentration (P<0.05). Plasma leptin concentration did not influence reproductive traits (days in milk at first breeding, service per conception and open days).
M Hoseeini Ghafari, Gh Ghorbani, H Rahmani,
Volume 13, Issue 47 (4-2009)
Abstract
This study was conducted to determine the influence of two intermittent (1wk) and abrupt drying off methods on udder health index of dairy cows with 30d dry period. Eighteen multiparous dairy cows were dried off approximately 4 wk prior to the expected calving time in a completely randomized design. For intermittent milk cessation treatment, cows were dried off in the following manner. Milk samples were collected from front and rear quarters at 7d to 3d prior to drying off, at drying off, 14d, 7d prior to calving, at calving, and 7d post calving. Milk yield at drying off day was recorded. Lacteal secretion samples were stored at -18Ċ and used for lactoferrin quantitation. Other samples were stored at 4Ċ for somatic cell count, total bacteria count and other milk components. The results indicated that, there were no differences in fat, protein and lactose percentages and milk pH between two drying off methods (P>0.05). However, there was a significant effect of drying off methods on lactoferrin concentration it was higher in dairy cows dried off by intermittent milk cessation, applied in 2 and 1 wk prior to calving time (P<0.01). Total bacteria count was not different in the two drying off methods. Milk total bacteria counts was higher in rear quarters compared to front quarters (P<0.05). Milk somatic cell counts were higher in cows dried off by abrupt milk cessation (P<0.05). There was a positive correlation between milk somatic cell counts and total bacterial counts (r = 0.352, P<0.01). No significant difference was observed in colostrum and milk lactoferrin concentration, somatic cell counts, fat, protein and lactose percentages, between rear and front quarters. With respect to higher lactoferrin concentration in cows dried off by intermittent milk cessation and due to antibacterial action of lactoferrin against mastitis pathogens, it seem that intermittent milk cessation treatment is preferred for cows given short dry period.
M Zibaei, R Rahmani,
Volume 13, Issue 48 (7-2009)
Abstract
In this study the causality relationship among variables in chicken and beef markets were investigated based on annual data from 1974 to 2004 in the I.S. of Iran. For this purpose, causality algorithms emerging from directed acyclic graphs were used in two cases, one based on co- integration analysis and innovation correlation matrix of Vector Error Correction Model (VECM) and the other using data directly. In the investigation of causality process, PC algorithm based on partial correlations and GES (Greedy Equivalent Search) based on Bayesian network model were used. The results revealed that there is no specific causality relation between chicken and beef consumption and their price indices. Thus it seems other variables and government interventions are effective factors in these markets. Therefore, this model is an instrument for forecasting changes of these variables. In these markets there are causality relations among price indices, quantities of consumption and other variables. Beef price index as endogenous variable, is under the effect of chicken price index, non meat food price index, non food price index, per capita expenditure and quantity of chicken consumption. The quantity of beef consumption is predetermined and isn’t under the effect of other variables. Chicken price index is endogenous and under the effect of beef price index, per capita expenditure and non food price index. Also chicken quantity consumption is endogenous and under the effect of beef quantity consumption and non meat food price index. With respect to the findings, for effectiveness, policy initiatives aimed at improving in meat industry should be different for different meat markets and the method of directed graphs can be used a s a guideline.
F Ahmadloo, M Tabari, A Rahmani, H Yosefzadeh,
Volume 13, Issue 48 (7-2009)
Abstract
This research was carried out to improve the growth and performance of Arizona cypress (Cupressus arizonica) and Medite cypress (C. sempervirens var. horizantalis) seedlings in different combinations of organic matter in nursery of Koloudeh, located in Amol city (north of Iran). Seeds in plastic pots were sown as a completely randomized design (RCD) with four replications at different soil treatments including: T1) nursery soil (control), T2) control soil: cattle manure (5:1), T3) control soil: decomposited litter (5:1), T4) control soil: cattle manure: decomposited litter (5:1:1). The results after one year showed that the seedlings of both species grown on T4 obtained the greatest shoot height, collar diameter, seedling Vigor Index, shoot dry weight, root dry weight, total dry weight and seedling Quality Index (QI) among all the soils examined. The response of most attributes to soil was better in Cupressus arizonica than in C. sempervirens. It is concluded that organic matter caused the increase of growth and biomass of seedlings in both species. It can be proposed that in order to enhance the performance and improvement of Quality Index of seedlings in nurseries, the status of physico-chemical of soil-media should be seriously evaluated.
M. Rahmanian, H. Khodaverdiloo, M. H. Rasouli Sadaghiani, Y. Rezaie. Danesh, M. Barin,
Volume 15, Issue 58 (winter 2012)
Abstract
Arbuscular mycorrhizae (AM) and Plant Growth Promoting Rhizobacteria (PGPR) associations are integral and functioning parts of plant roots. These associations have a basic role in root uptake efficiency as well as improvement of plant growth in degraded environments including heavy metals contaminated soils. This study was conducted to evaluate the effects of heavy metal-resistant soil microbe's inoculation on bio-availability of Pb and Cd in soil, plant growth as well as metal uptake by Millet (Pennisetum glaucum), Couch grass (Triticum repens) and wild alfalfa (Medicago sativa). A soil sample was treated by different levels of Pb and Cd (soil 1). Native microbial inoculums were obtained from alfalfa rhizosphere soils adjacent to Pb and Cd mines in Zanjan region (soil 2), then added with weight ratio of 1:5 (w/w) to soil 1. Host plants including millet, couch grass, and alfalfa were grown in pots and kept in greenhouse conditions. At the end of growing period, shoot dry matter and Pb and Cd concentrations in plant and soil were measured. Results indicated that plants yield and Pb uptake were significantly higher in non-inoculated treatments (p ≤ 0.05). However, Cd uptake by plants was greater in inoculated treatments (p ≤ 0.05). Couch grass showed the most accumulation potential of Cd and Pb among the studied plants.
H. Rahmani, A. Lakzian, A. R. Karimi Karouyeh, A. Halajnia,
Volume 17, Issue 65 (fall 2013)
Abstract
Urease is one of the most important enzymes in nitrogen cycle. The clay particles (with high surface area) play an important role in the stability of these protein compounds (enzymes) against various environmental factors. In order to examine the interactions between urease with sepiolite and vermiculite, three in vitro experiments were conducted separately in a completely randomized design. Two experiments were carried out with two replications. Treatments included six incubation times (0, 1, 2, 5, 10 and 20 days) and five levels of temperature (10, 20, 30, 40 and 50 ˚C). The third experiment was carried out in a factorial arrangement with two replications. Factors included three levels of pH (5, 7 and 9), and six-levels of enzyme concentrations (0.05, 0.25, 1, 5, 15 and 30 units). The results showed that the activity of adsorbed enzyme was more than free enzyme during the incubation time. The optimum temperatures for activity of free and adsorbed enzymes were 30 and 50 ˚C, respectively. It was concluded that enzyme adsorption on clay surfaces increases enzyme stability against environmental changes. Also, the results showed that the highest levels of urease adsorption on sepiolite and vermiculite occurred at pH 9 and 7, respectively. Adsorption isotherms of Enzyme showed that Vermiculite adsorbed urease with higher affinity compared to Sepiolite.
V. Jahandideh Mahjen Abadi, M. Sepehri, A.h. Khoshgoftarmanesh, H. R. Eshghizadeh, D. Rahmani Iranshahi,
Volume 19, Issue 71 (spring 2015)
Abstract
Zinc deficiency is the most widespread micronutrient disorder in the production of wheat (Triticum aestivum L.) and other cereal crops. An experiment was conducted in greenhouse, in 2013, using the sterile sand-perlite (2:1 v/v), to study the effects of two beneficial microorganisms on growth and nutritional status of wheat (Nicknejad cultivar). The study was arranged as factorial in a completely randomized design with three replications. The experimental factors consisted of Piriformospora indica (E0: Uninoculated E1: Inoculated), Pseudomonas putida (E0: Uninoculated E1: Inoculated) and Zinc (Zn0: 0 Zn1: 2µM ZnSO4 ). The results showed that inoculation by P. putida increased shoot dry weight at both levels of zinc, but this increase was observed for root dry weight only without zinc application. The iron concentration of shoot was decreased as a result of inoculation by P. putida at both levels of zinc. However, P. indica inoculation increased iron concentration in zinc application, but had no significant effect without zinc application. At both levels of zinc, the highest P, Zn, chlorophyll a and b concentrations were achieved by inoculation with P. indica. Inoculation by P. putida reduced P concentration at both levels of zinc but it reduced Zn, chlorophyll a and b concentrations only with zinc application. The results of this research showed that despite negative effect of P. putida on nutrient uptake, inoculation by P. putida and/or P. indica plays an important role in the promotion of wheat growth in zinc deficiency conditions.
M. R. Asgharipour, B. Rahmanian Koshki,
Volume 19, Issue 71 (spring 2015)
Abstract
The aim of this study was to evaluate phytoavailability of cadmium to lentils after the application of composted animal manures. In a greenhouse experiment, two lentil (Lens culinaris) cultivars were grown in the soils applied with different levels of Cd from animal manure compost, and compared with Cd applied as cadmium chloride or their combination. Phytotoxicity of Cd was determined as plant growth, Cd accumulation, and the uptake of macronutrients. Addition of Cd significantly reduced plant growth and plant weight as well as plant water content. Phytotoxicity of Cd applied through manure composts was significantly less than the same rate of Cd amended with soluble CdCl2, suggesting the lower potential hazard of composted manure-applied Cd. Plants accumulated substantial amount of Cd in different plant parts. Most of the Cd taken up was retained in roots, and lentil roots had higher concentrations of Cd than the stem. Phytotoxicity of applied Cd in Ziba was significantly greater than that in Zabol cultivar. Cadmium addition especially as metal salt reduced nutrient concentrations in the shoot, and caused more nutrient accumulation in roots, probably due to the inhibition of their translocation to plant shoots. The results of this experiment point to the fact that the Cd source and loading rate are important factors in evaluation of Cd phytoavailability.
H. Rahmani, A. Lakzian, A. R. Karimi, A. Halajnia,
Volume 20, Issue 78 (Winter 2017)
Abstract
Urea is one of the most commonly used nitrogen fertilizers in agricultural lands. The fate of this fertilizer in soils is greatly related to the soil urease enzyme activity, while this enzyme commonly exists in the adsorbed state on the surface of soil colloids, and especially clay minerals. In order to examine the kinetic properties of free and adsorbed Urease on the surface of sepiolite and vermiculite, an experiment was carried out with eight levels of urea concentration (5, 10, 20, 40, 60, 80, 100 and 120 mM). This experiment was done with enzyme concentration of 1 unit in temperature of 25˚C and pH=7. Adsorption of urease on the clay surfaces affected its kinetic properties compared to the free state. The results showed that urease enzyme obeyed Michaelis-Menten kinetic in both free and adsorbed states on the clay surfaces. Except free urease, the highest and lowest values of Vmax and Km were observed in urease-sepiolite and urease-vermiculite complexes, respectively. Also, the results showed that except free urease, the highest levels of Catalytic Efficiency were related to urease in the presence of vermiculite and sepiolite, respectively. The Effectiveness Factor was more for adsorbed urease on the sepiolite surface than adsorbed urease on the vermiculite surface, and the fact somehow suggests more complete diffusion in the presence of sepiolite.
A. Hemmati, H. Asadi Rahmani,
Volume 22, Issue 4 (Winter 2019)
Abstract
In order to study the effects of rhizobium bacteria and arbuscular mycorrhizal fungi on water use efficiency and the grain yield of bean, under drought stress conditions, two-year year field experiments were conducted during 2015 and 2016 growing seasons. The experimental design was a split plot arranged in an RCBD with 4 replications. Three irrigations including S1= 95-100% AW (Normal irrigation), S2= 75-80% AW(Moderate drought stress) and
S3= 55-60% AW (severe drought stress) were assigned to the main plots and six bio fertilizer treatments including T1=177 rhizobium bacteria strain, T2=160 rhizobium bacteria strain used for seed inoculation, T3= mycorrhizal arboscular fungi used for soil inoculation, T4= T1+T2, T5= T1+T2+T3 and T6= control (no seed and soil inoculation) were randomized to the subplots. Based on the combined analysis of variances for two years, there were significant differences (p˂0.05) in the grain yield, yield components and water use efficiency between the irrigation stress and bio fertilizer treatments. The highest grain yield (2371 kg ha-1) and water use efficiency (522 g m-3) were obtained in the S2T2 treatment. In this treatment, 160 and 177 rhizobium bacteria (T2) in moderate drought stress (S2) were used. These results suggested that inoculation with the rhizobium of seed bean in arid and semi-arid areas could improve yield, water use efficiency and resistance to drought stress by increasing the growth in the root and shoot of the plant.
Z. Maghsodi, M. Rostaminia, M. Faramarzi, A Keshavarzi, A. Rahmani, S. R. Mousavi,
Volume 24, Issue 2 (Summer 2020)
Abstract
Digital soil mapping plays an important role in upgrading the knowledge of soil survey in line with the advances in the spatial data of infrastructure development. The main aim of this study was to provide a digital map of the soil family classes using the random forest (RF) models and boosting regression tree (BRT) in a semi-arid region of Ilam province. Environmental covariates were extracted from a digital elevation model with 30 m spatial resolution, using the SAGAGIS7.3 software. In this study area, 46 soil profiles were dug and sampled; after physico-chemical analysis, the soils were classified based on key to soil taxonomy (2014). In the studied area, three orders were recognized: Mollisols, Inceptisols, and Entisols. Based on the results of the environmental covariate data mining with variance inflation factor (VIF), some parameters including DEM, standard height and terrain ruggedness index were the most important variables. The best spatial prediction of soil classes belonged to Fine, carbonatic, thermic, Typic Haploxerolls. Also, the results showed that RF and BRT models had an overall accuracy and of 0.80, 0.64 and Kappa index 0.70, 0.55, respectively. Therefore, the RF method could serve as a reliable and accurate method to provide a reasonable prediction with a low sampling density.
S. Moghim, J. Rahmani,
Volume 25, Issue 1 (Spring 2021)
Abstract
Improper water managements and overuse of surface water and groundwater mainly for agricultural purposes in Iran have led to the drying of many rivers and groundwater. Climate change adds an extra pressure on the water resources. These changes indicate the necessity of adjustment in water management plans. This study used hydroclimatic variables including precipitation and temperature in Urmia Plain to find appropriate crops that needed the minimum irrigation water. In addition, the best time for planting each crop is determined. To find the proper crops for the region, the daily water, as required for each crop, was calculated based on climate condition, crop type, and crop growth stage. The results indicates that grape could be the best crop for the region. In addition, early planting (e.g. in spring) reduced the irrigation water needed due to more rain and soil moisture in spring than summer, which could provide crop water requirement. On the other hand, the increased temperature in spring could satisfy heat units required for the fully grown plants like barley.
