فهرست مطالب پیمان کشاورز

In this study, TiO2 and Fe2O3 nanoparticles were used in enhancing CO2 absorption and stripping. For this regards, mentioned nanoparticles at different concentration were applied to 10 wt.% MDEA solution for CO2 absorption/desorption at a bubble column. Also, the Zeta potential analysis were studied to evaluate of all nanofluids stability and the experimental results of CO2 absorption and stripping was reported in presence nanoparticles. The results reveals that all nanofluids had better capability for CO2 absorption, TiO2 nanofluid with 0.1 wt.% concentration can increased CO2 absorption up to 28.4%, that it had highest performance than the other nanofluids due to more stability. In addition, the experimental tests of regeneration were shown lower ability of Fe2O3 nanoparticles on CO2 stripping than the TiO2 due to lower stability. Accordingly, TiO2 and Fe2O3 nano fluids at 0.05 wt.% concentration and 70oC regeneration temperature were lead to raising CO2 desorption as 25.8% and 24.5%, respectively.

 Soil is one of the main drivers of global warming through losing carbon in the form of CO2. On the other hand, its ability to sequester carbon is a suitable option for reducing CO2 emissions. Therefore, even few changes in carbon sequestration or decomposition of soil organic carbon affect the global atmospheric CO2 content. Although the soils of arid and semi-arid regions have low organic carbon content, they can sequester substantial amounts of carbon due to the large area of these regions. So, the Rothamsted carbon model was used to predict the impact of future climate changes on the amount of CO2 emissions and low soil organic carbon stocks in the semi-arid arable lands of Razavi Khorasan province. This model is one of the most widely used models for the study of soil organic carbon turnover and has been evaluated in a variety of ecosystems including grasslands, forests and croplands and in various climate regions. The RothC model is consists of five conceptual soil carbon pools, four active fractions and a small amount of inert organic matter (IOM) that is resistant to decay. The active pools splits into: Decomposable Plant Material (DPM), Resistant Plant Material (RPM), Microbial Biomass (BIO) and Humified Organic Matter (HUM). This model is able to reveal the effect of soil texture, temperature, rainfall, evaporation, vegetation and crop management on the soil organic carbon turnover process.

 The Rothamsted carbon model was calibrated and validated using data measured in 2020 and available data from the long-term field experiments in the semi-arid agricultural lands of Jolge Rokh. Then, by analyzing the climate change of the study area, the impact of climate change until the end of the current century on the amount of CO2 cumulative emissions, total organic carbon (TOC) and active carbon pools model were modeled and compared in the current climate and also climate change conditions.

 The comparison between the measured and simulated soil organic carbon values by the model shows the potential of the model to provide predictions with acceptable accuracy. The outcome of comparisons revealed that R2, Root Mean Square Error (RMSE), Mean Difference (MD), Mean Absolute Error (MAE) and Model efficiency were 0.97, 2.78, 2.11, 2.33 and 0.70 respectively. Assessment of climate changes in the region (during 1981-2020) showed a decrease in precipitation and a significant increase in temperature over the past 40 years. Climate change simulation was carried out by temperature increasing and decreasing the precipitation until the end of the current century, indicated the decrease of all active carbon pools. It was found that DPM, RPM, BIO, HUM and TOC decreased respectively to 2.41, 2.72, 2.51, 1.04 and 1.32% compared to the current climatic conditions, while the cumulative CO2 emission increased by 1.26%. Temperature rising leads to increase the rate modifying factor (a) by 2.20%, which enhances microbial respiration and decomposition rate of organic carbon and CO2 emissions (carbon output). However, it also increases the ecosystem's net primary productivity (carbon input). Decreases in rainfall and increase in potential evapotranspiration cause a reduction of the rate modifying factor (b) to 0.23%, which on one side reduces the activity of microorganisms and carbon biodegradation; but on the other side, it decreases the vegetation cover and following that reduces CO2 trapping during the photosynthesis process and transfers it to the soil. It seems that in arid and semi-arid climates where the lack of moisture is the most important limiting factor of the plants growth; the role of precipitation in carbon decomposition and sequestration is greater than temperature.

 The Rothamsted carbon model is suitable for regional simulations because it requires only easily obtainable inputs. Therefore RothC is an appropriate tool for estimating long-term effects of climate change and agricultural management (such as application of manures, returning plant residues to the soil, crop rotations, conservation tillage etc.). The RothC model validation in the cold semi-arid agricultural lands of the region, shows the ability of model to properly simulate the pattern of organic carbon changes. Also, simulation of soil organic carbon changes under the climate changes conditions indicates an increase in cumulative CO2 emissions and decrease in soil organic carbon pools of the study area. The methodology can be applied to other regional estimations, provided that the relevant data are available. The predictions allowed to identify the land management potential to carbon sequestration. Such information demonstrate a beneficial tool for evaluation of past land management effects on soil organic carbon trends and also estimation of future climate change effects on soil organic carbon stocks and CO2 emissions.

Soil organic carbon is a key element in determining soil quality, health, and fertility. Due to the complexity of the structure and relationships of soil organic carbon pools, the use of models is beneficial in identifying the reaction of these pools to the change in ecosystem conditions. So, by using the RothC model, the effect of global warming and climate change on the amount of soil organic carbon pool of the agricultural ecosystem of southeastern of Mashhad was investigated. Therefore, the model was calibrated and validated using data measured in 2020 and available long-term data. Comparing the measured values of soil organic carbon and the simulated values by the model, the coefficient of determination (R2) was 0.89. Root means square error (RMSE): 3.45, mean difference (MD): 1.84, mean absolute error (MAE): 2.79, and model efficiency (EF) was 0.73, demonstrating the validity and suitability of the model. The modeling of the future climate changes of Mashhad showed a decrease in rainfall and an increase in temperature and evaporation, leading the amount of total soil organic carbon (TOC) would decrease by 1.13% compared to the current conditions. Considering the decomposition rate constant of the model's four active carbon pools, humus exhibited the slowest decomposition rate of 0.96%. At the same time, decomposable plant materials (DPM), resistant plant materials (RPM), and microbial biomass (BIO) were decreased by 1.18%, 2.21%, and 2.10%, respectively, compared to the current climate condition. Moreover, over time, the decomposition rate decreased due to the decay of active organic matter pools that are easily decomposed.

According to the importance of water vapor available in the natural gas, achieving a powerful absorbent looks quite necessary. In this study, for the first time, tetraethylene glycol (TREG) and its mixture with triethylene glycol (TEG) were used to remove water vapor from a wet air stream. Following this, to achieve a good vision about the performance of TREG, the results were compared with the pure TEG and the impact of gas flow rate was considered. Based on the obtained results, all absorbents applied in this work resulted in a better performance in lower gas flow rates. Further, although TEG was the best absorbent at low gas flow rates, TREG had the best performance in water vapor removal at high gas flow rates. Finally, in the best operational condition in this work, the use of TEG led to the reduction of water vapor from 90% to about 10% at 60 ml.min-1. However, applying TERG had a better result at 120 ml.min-1 and caused the water vapor to reduce from 90% to approximately 5%. High water vapor absorption in high flow rates indicates the high capability of TREG to employ in gas dehydration processes in industrial scales.

A national project was carried out in 10 provinces in order to compare the fertilization method of farmers with the integrated method of soil fertility recommendation for canola plants. The experiment included 54 farms in the provinces of Golestan, Mazandaran, Khuzestan (Dezful), Khuzestan (Ahvaz), Ardabil (Maghan), East Azerbaijan, Isfahan, Bushehr, Khorasan Razavi, Kermanshah, Fars and Varamin regions. These areas consisted of a wide range of canola cultivation regions, climatic conditions and a different range of soil characteristics. In a part of selected fields, fertilization was recommended based on the soil test (optimal use of fertilizers) and in the other half of the fields, application was according to the traditional method of the farmer in the region. At the end of the growth stage, the seed yield of treatments was compared in each province and in each region. According to the results, phosphorus had the highest percentage of deficiency in the soil of the fields, and among the micro nutrients, the highest deficiency was related to the zinc element. On average, the increase in grain yield of first year was 600 kg ha-1 or 24%, compared to the conventional treatment. In the second year, the increase in grain yield was 784 kg ha-1 or 27.4%. For the average of two years, the amount of 692 kg ha-1 or 25.7% increase in grain yield was obtained. The benefit to cost ratio of different regions depended on the characteristics of the soil and the amount of used fertilizers. The highest value of this ratio was obtained from the region of Neishabur (26.52) and Darab (22.31. The lowest was obtained from Bushehr (0.28). The results showed that the consumption of fertilizers with considering the time, quantity, source and method of application will improve the yield of canola in all regions.

The main goal of this research is dynamic modeling and optimization of the steam methane reforming process in an industrial hydrogen plant in a crude oil refinery. In the first step, the process is heterogeneously modeled based on the mass and energy balance equations considering catalyst deactivation. Since the reforming reactions are under mass transfer control in the catalyst, the effectiveness factor is calculated and applied in the model. Then, to verify the accuracy of the model, the simulation results are compared with the plant data. The simulation results show that hydrogen production capacity decreases and approaches from 27.4 to 24.4 mole/s due to catalyst deactivation. In the next step, considering the uniform hydrogen production as an objective function and operational limitations in the process, a single objective optimization problem is formulated to overcome the production decay. Based on the formulated optimization problem, the optimal dynamic trajectories of feed temperature, furnace temperature, and steam to methane ratio are calculated during the process run time. Based on the simulation results, the hydrogen production is improved by about 6% applying optimal conditions to the system.

Soil organic carbon is one of the most important basis for assessing soil quality, health, and fertility. Therefore, accurate, rapid, and inexpensive measurement of soil organic carbon is essential to determine efficient management and conservation practices, which might increase carbon sequestration or preservation in soils. Soil carbon measurement methods are generally classified into two categories: ex-situ and new in situ methods. The first category includes traditional field-collected samples and chemical laboratory degradation of soil organic matter using wet and dry combustion methods. These methods are often expensive, time-consuming, and environmentally destructive. In many cases, common sampling and laboratory errors have resulted in these approaches to be less precise. In situ methods, including infrared reflectance spectroscopy, laser-induced breakdown spectroscopy, inelastic neutron scattering, and remote sensing, are considered more efficient, especially in large-scale national studies as utilizing such methods may increase the speed and accuracy of measuring and significantly reduce the cost of conventional field sampling and laboratory analysis. National quality monitoring of Iranian agricultural soils showed that in more than 60% of lands, soil organic carbon content is less than one percent and further studies have confirmed the declining trend of organic carbon storages in most parts of the country. On one hand, more than 80% of Iran's land area is located in an arid and semi-arid climate whose soils are low in organic carbon content, and on the other hand, the salinity and predominance of calcareous soils in vast areas of Iran have become controversial issues, which have made the attempts to find the correct method of measuring the organic carbon of these soils more complicated. Although the use of an automated carbon analyzer is considered as the standard method for comparing the ex-situ soil carbon measurements, the incomplete conversion of carbonate to CO2 under the combustion conditions in highly calcareous soils might happens which is problematic. Therefore, the use of wet combustion methods is more popular because it’s not affected by the presence of carbonates and the direct calculation of organic carbon. All soil organic carbon measurement methods have strengths and weaknesses, so its choice depends on the characteristics of the studied soils, the purpose of the project as well as the financial considerations, and the allocated budget. Considering the lack of comprehensive studies in this field, the present study aims to help to gain a better understanding of the results of the Walkley Black method, as the basic method of measuring soil organic carbon in Iran, and to assist with developing a standard and robust protocol for measuring the organic carbon of saline and calcareous soils of Iran, and finally to comparatively evaluate the soil carbon measurement methods by outlining their strengths and weaknesses.

Soil quality can be considered as a comprehensive index for sustainable land management assessment. Studying the most important soil physical properties and combining them as an index of soil physical quality (SPQI) could be used as an appropriate criteria for evaluating and monitoring soil physical changes. In this regard, this study was conducted to determine the most important soil physical properties and calculate the SPQI of medium to coarse-textured soils of Khorasan-Razavi province.
Torogh Agricultural and Natural Resources Research and Education Station of Khorasan-Razavi province is located in south-east of Mashhad city (59° 37' 33"-59° 39' 10" E, 36° 12' 31"-36° 13' 56" N). Soil texture variability in this research station is one of its outstanding features. The soil textures are classified into loam, silt loam, silty clay loam, clay loam, and sandy loam. More than 90% of agricultural soils in Khorasan-Razavi province are classified in these five texture classes. Using the available data, 30 points with different soil textures and OC contents were selected. The soil samples were collected from 0-30 cm soil depth at each point. Intact soil cores (5 cm diameter by 5.3 cm length) were used for sandbox measurements, and disturbed soil samples were used to determine other properties. Required laboratory analysis and field measurements were conducted using standard methods. In this research, 35 soil physical properties as total data set (TDS) including: soil moisture release curve (SMRC) parameters, particle size distribution and five size classes of sand particles, soil bulk and particle density, dry aggregates mean weight diameter (MWD) and stability index (SI), S-index, soil porosity and air capacity, location and shape parameters of soil pore size distribution (SPSD) curves, relative field capacity (RFC), plant available water measured in matric pressure heads of 100 and 330 hPa for the field capacity (PAW100 and PAW330), least limiting water range measured in matric pressure heads of 100 and 330 hPa for the field capacity (LLWR100 and LLWR330), integral water capacity (IWC) and integral energy (EI) of different soil water ranges were measured and calculated for 30 soil samples. The most important soil physical properties were selected using principal component analysis (PCA) method by JMP (9.02) software. Selected physical properties as minimum data set (MDS) were weighted and scored using PCA results and scoring functions, respectively. In this study, three types of linear scoring functions were used. The soil physical quality index (SPQI) was calculated by two scoring and two weighting methods for each soil sample and the differences between these four SPQIs were tested by sensitivity index.
Principal component analysis results showed that among 35 soil physical properties (TDS) which were studied at this research, six properties of mean pore diameter (dmean), PAW100, total porosity (PORT), EI LLWR330, SI and PAW330 accounted for about 90% of the variance between soil samples. Weight of the selected properties (MDS) was calculated by the ratio of variation in the data set explained by the PC that contributed the selected property to the total percentage of variation explained by all PCs with eigenvalue ˃ 1. In this research, the parameters of PAW100, total porosity (PORT), SI and PAW330 were scored using scoring function of more is better, EI LLWR330 was scored using scoring function of less is better and dmean was scored using scoring function of optimum by two scoring methods with score ranges of 0.1-1 and 0-1. Considering unweighted and weighted MDS and two ranges of scores, four SPQIs were calculated for each soil sample. The results showed that SPQIs which were calculated by the MDS derived from PCA method and scoring weighted MDS at the range of 0-1, had the highest sensitivity index and could represent the differences between the studied soil samples better than other SPQIs. By this method, maximum and minimum SPQI values for the studied soils were 0.82 and 0.12, respectively. SPQI is a relative comparison criterion to quantify the soil physical quality which could be applied only for the studied soils with specific characteristics.
The results of this research showed that minimum data set (MDS) explained about 90% of the variance between soil samples. Combining MDS into a numerical value called soil physical quality index (SPQI) could be used as a physical comparison criterion for the studied soils. From the SPQI based on the MDS indicator method, soil quality was evaluated quantitatively. Soil samples with grade I, II, III, and IV accounted for 10%, 36.7%, 30%, and 23.3% of the soil samples, respectively.

Nitrogen use efficiency (NUE) is a critically important indicator for judging the wise use of N fertilizer in crops. It can be affected by management factors or soil properties. This study was conducted to estimate NUE in wheat based on large scale fields (20 wheat farms) trials and determining the role of soil factors, in Khorasan Razavi province. Two levels of N as urea (0 and conventional) were applied in each of the fields. In the fields, grain yield (conventional) was divided into low yield population (LYP, GY< 5 Mg ha-1) and high yield population (HYP, GY ≥ 5 Mg ha-1) categories. Then, apparent recovery efficiency (ARE), physiological efficiency (PE), agronomic efficiency (AE) and Partial Factor Productivity (PFP) were calculated for N in both yield populations. The results showed that nitrogen efficiency indices in both yield populations were much lower than optimum level. However, AE (8.2 kg/kg), ARE (25%), and PFP (46 kg /kg) in the HYP were more than in the LYP, but there was no difference between PE in both yield populations. There was a significant correlation between AE and soil organic carbon (r = -0.97, P <0.01,   also ARE with soil organic carbon (r = -0.82, P<0.05) and soil clay content (r = 0.68, P <0.05) for LYP in contrast to the HYP). While PFP exhibited positive correlation with soil organic carbon (r = 0.86, P <0.01) and negative correlation with soil electrical conductivity (r = -0.77, P <0.05) for LYP, this relationship was weaker with soil organic carbon in HYP. None of soil factors had a significant effect on PE. These results show that soil factors such as organic carbon, salinity, and clay content of soil had a decisive role in AE, ARE, and PFP in the LYP. In contrast, soil factors had no effect on nitrogen efficiency indices in the HYP (with the exception of the effect of soil organic carbon on PFP).

  Agricultural soils in Iran, as in many other countries, are slightly to moderately contaminated by cadmium. According to some published reports, the average content of cadmium in some agricultural products and soils of Iran was found to be above the FAO/WHO guidelines. Abiotic stresses including cadmium stress can lead to overproduction of reactive oxygen species (ROS) causing progressive oxidative damage and ultimately cell death. In order to reduce cadmium-induced toxicity and alleviate some adverse effects of this metal on plants, a number of strategies including phytoremediation have been developed. Meanwhile, it was found that application of some elements such as calcium could diminish adverse effects of heavy metals in plants. In addition to calcium, selenium due to its potential in mitigation of cadmium toxicity has gained increased attention in recent decades. Selenium, as an antioxidant, plays an important role in the maintenance of human health, and on the other hand, many soils and, consequently, the crops produced in them suffer from the deficiency of this element. Although some studies have reported protective roles of selenium in plants subjected to cadmium stress, due to the limited reports on the effects of selenium on wheat exposed to cadmium stress particularly under Iranian soils conditions, the present study was conducted. In winter 2015, a pot experiment was carried out based on a completely randomized design in factorial arrangement with three replications for each treatment at research greenhouse of agriculture faculty of Ferdowsi university of Mashhad, Iran. The site is situated at 36°2′ North latitude, 59°4′ East longitude at an altitude of 999.2 m above mean sea level. The experiment included four levels of selenium (0, 0.5, 1, and 4 mg kg -1 soil, in the form of sodium selenite) and three levels of cadmium (0, 5, 15 mg kg -1 soil, in the form of cadmium nitrate). Soil weighing 6 kg was put into polyethylene pots, irrigated with distilled water to field capacity each three days and left over for 45 days to attain equilibrium. Eight seeds of wheat (Triticum aestivum L. cv. Falat) were sown per pot and thinned to four plants after the seedlings of wheat were well established. Sixty days after germination, newly expanded leaf samples from each pot were taken for determination of leaf pigments, proline and enzyme activity. Meanwhile, shoots from each pot were harvested from 1 cm above the soil and rinsed four times (twice with distilled water, once with 20 mM EDTA and again once with distilled water). The samples were wiped with paper and oven-dried at 50 °C for one week. Finally, dry weight of the shoots was measured. Cadmium stress, selenium application, and their interactions had a significant effect on photosynthetic pigments concentration, proline content, catalase activity and shoot dry weight. Results showed that as cadmium concentration in soil increased, chlorophyll a, b concentration, carotenoids content, catalase activity and shoot dry weight decreased. In contrast, the accumulation of proline in the plants was stimulated after the cadmium treatment, by 25 % in the presence of the highest cadmium level, as compared to the lowest cadmium level. Selenium application exerted its positive influence on some physiological parameters in plants exposed to cadmium stress. Chlorophyll b concentration and enzyme activity were higher in plants treated simultaneously with selenium and cadmium as compared with plants treated solely with cadmium. However, selenium did not show positive effect on chlorophyll a concentration, carotenoid content and shoot dry weight in plants grown under cadmium stress. Meanwhile, selenium at high concentration had no beneficial effect on wheat but also led to a significant decrease in photosynthetic pigments content, enzyme activity and shoot dry weight. The results of the present study revealed that cadmium stress negatively affected physiological parameters of wheat and decreased photosynthetic pigments concentration, catalase activity and shoot dry weight. In contrast, selenium supplementation at low concentration could improve partially some physiological responses in wheat under cadmium stress.

Pear producers around the world are looking for faster return of capital and saving in labor costs, achieved well by high density orchard planting. Choosing a good combination of scion and rootstock is critical for production of fruit trees because the relationship between the rootstock and scion has a decisive effect on plant water relations, leaf gas exchange, plant size, flowering, fruit production, fruit quality and production efficiency. Nowadays in some regions, growers are using quince rootstock for pear orchard establishment. Using the quince rootstock alleviates many problems in pears orchard, but graft incompatibility between pear scion and the quince rootstock, and resistance to frost and alkaline soils are some problems restricting the use of this rootstock. In most pear-producing regions in Iran, pear seedling is used for pear propagation. Due to the problems of pear including overgrowth and late precocity (after 4 -5 years), this research evaluated the effects of pear clonal rootstock (Pyrodwarf, OHF and Quince c) on some growth characteristics in comparison to pear seedling (Pyrus communis).
This research was conducted during 3 years from 2014-2016 in Chenaran (36.6, 59.1) in northeast of Mashhad. Maximum and minimum temperatures were 40 and -22 ˚C, respectively, elevation 1176m and the average annual rainfall 240mm. The same tissue culture rootstocks from two cultivar Pyrodwarf and OHF with Quince rootstock and annual seedling from Dragazi pear were selected in August 2013 and T-budded with three commercial cultivars Spadona, Ntanz and Sebri. In the spring of 2014, after relieving frost danger, the trees were planted in field with row space 4×2m. In order to investigate dwarfing effect of rootstock on scion cultivar, some important vegetative factors that represent dwarfing effect of rootstock including trunk cross sectional area, height of tree, amount of lateral branch growth, tree growth rate during growth season, mean of growing buds on each lateral branch, and stem and leaf water potential were measured. This test was conducted in factorial based on randomized complete block design with 4 replications. Each plot was included one hybrid combination. MSTATC and Excel software were used for data analysis, and differences among means were compared by using LSD test.
Different rootstocks did not show any significant difference in terms of leaf water potential. Leaf water potential during the seasons had a constant time course about scion cultivar on all rootstock so while temperatures rise throughout the season it reduced the amount of leaf water potential. The effect of cultivar was significant on leaf water potential so that the highest water potential was related to Natanz and the least water potential was related to Serbi cultivar. The effect of rootstock and scion both on stem water potential was significant. Therefore the highest and lowest stem water potential was recorded for cultivars grafted onto the seedling and quince rootstock, respectively. In this study, a significant relationship was observed between minimum stem water potential (mid-day) and branch growth rate during the growing season. With reducing stem water potential as a result of temperature increase, the amount of branch growth reduced. The effect of both scion and rootstock on chlorophyll index was significant. In this investigation, all 4 rootstocks had different effects on chlorophyll index. The highest chlorophyll index was related to cultivar Natanz and the least was related to Spadona. Sebrie had medium chlorophyll index. Rootstock effect on vegetative growth of the scion was not significant but the effect of scion was significant at 5% level. Pear seedlings with vigorous growth had more long branches than other rootstocks. In the present research, seedling rootstock also induced higher growth of lateral branches. Furthermore, quince rootstock induced the least growth of lateral branch during 3 years of the investigation. In addition, quince rootstock had the minimum tree height and pear seedling had the maximum tree height. Internode length in dwarfing rootstock was less than seedling. Both scion and rootstock had significant effect on trunk sectional area so that at the end of three years, cultivars grafted on seedling rootstock had the highest trunk cross sectional area, and cultivars on quince rootstock had the lowest TCSA. Two vegetative pear rootstocks (Pyrodwarf and OHF) did not show significant difference from each other. Pyrodwarf and OHF rootstock showed good compatibility with Natanz and Spadona scions like seedling rootstock. On the other hand, the survival percentage on quince rootstock was really low.
This investigation showed that pear rootstock had less vegetative growth than seedling rootstock and induced dwarfing effect on scion growth during 3 years but quince rootstock had more dwarfing effect.

World cereal demand is growing at present in accordance with the global expansion of human populations. Deficiency of micronutrients in cereal cropping is one of the major worldwide problems. Beside of lowering grain yield, it may cause some healthy problems in human populations. Iron is an essential micro element in the soil that mainly had been found as the insoluble (Ferric or Fe3) form. Although ferric iron is relatively insoluble in water, the solubility of total inorganic iron decreases between pH of 7.4 to 8.5 range which is dominant in calcareous soils. It is estimated that nearly half of the world population is affected from Fe deficiency problem. Major reason for widespread occurrence of Fe deficiency in human populations is very little dietary diversity and high consumption of cereal-based foods with very low amount and poor availability of Fe. Bread wheat is the most widely grown cereal grain with 65% (6.5 million hectares) of the total crop cultivated area in calcareous soils of Iran. Most wheat cultivars currently used have been selected for high yields under optimum fertilizer conditions. Consequently, research is needed to select efficient genotypes that will grow and produce under conditions of lower fertilizer input or soil micronutrients deficiencies. This is especially true for the expansion of wheat cultivation which is often growing in calcareous soil of Iran. These soils are characterized with low fertility, high pH value, low organic matter content and low micronutrients availability. Environmental concerns in wheat production for human population indicate that to improve wheat quality and quantity, the zero or possible lowest amounts of chemical fertilizers would be applied. In this regard, the use of iron-efficient genotypes that have also high yield can be considered as a key strategy.
In order to investigate Fe efficiency in various wheat genotypes, a factorial experiments a randomized complete block design was carried out with three replications in agricultural and natural resource research and education center of Khorasan Razavi province, Mashhad (Torough Station), Iran, during 2009-2011. Treatments were consisted of two levels of Fe fertilizer (0 and 10 kg h-1 as Fe-EDDHA) and six genotyps of wheat including: three cultivars and one line of bread wheat (Alvand, Falat, Toos, and C75-5, respectively), two species of wheat known as Thriticosecale and Durum. The trial plots’s size was 9×3.6 (32.4 m2). According to the results of soil analysis, total nitrogen, available forms of phosphorus and potassium were 0.05%, 7.2, and 180 mg kg-1, respectively. DTPA extractable of iron, zinc, manganese and copper were 2.4, 0.52, 3.4 and 0.7 mg kg-1, respectively. Soil texture was silt loam. Soil organic carbon percentage and equivalent CaCO3 percentage (T.N.V) were 0.48% and 18.7%, respectively. The electrical conductivity (EC) and pH measured in saturated extract were 1.4 dSm-1 and 8.1, respectively. At defined phonological stage (SG6 based on Fix’s Index), the Fe concentration in shrub was measured. Moreover, grain yield and Fe uptake by grain were determined at the end of ripening stage. Iron use efficiency, agronomic efficiency and apparent recovery efficiency were calculated and studied as dependent variables.
The grain yield is the most integrative trait of a particular genotype. The results showed that Fe application increased significantly grain yield by 9.9% in comparison with control. In our research the highest grain yield increase due to Fe application was found in Durum wheat (17.1%), and the lowest grain yield increase, were found in Toos cultivar (4.1% yield increase). Application of Fe increased Fe concentration and uptake in grain about 5.7% and 16.4%, respectively. In terms of iron uptake by grain, Thriticosecale wheat and C75-5 cultivar had the highest (339.6 g ha-1) and the lowest amounts of Fe uptake (260.3 g ha-1), respectively. Also, application of Fe had no significant effects on Fe concentration in shoot. Fe use efficiency in bread wheat genotype, Durum and Thriticosecale wheat was ranked as: Durum There were various abilities to uptake and use Fe by different wheat genotypes. Fe-efficient genotypes of wheat were Toos and Falat also Triticale. Moreover, these genotypes also had higher grain yield.

Soil physical quality isone of the most important factors affects plants water use efficiency in agricultural land uses. In the literature, some soil physical properties and indices such as S-index, Pore Size Distribution (PSD), porosity, Air Capacity (AC), Plant Available Water (PAW) content, Least Limiting Water Range (LLWR) and Integral Water Capacity (IWC) were mentioned as the soil physical quality indicators. It has been reported that the soils with the same PAW, LLWR and IWC may have different physical qualities. The index of Integral Energy (EI) of the soil moistureranges may differ between the soils with equal soilmoistureover a defined water content range. This index is defined as the required energy to uptake the unit mass of soil moistureby plants. According to this definition, the soils with low EI would have better physical quality for plants roots growth. In this research, we hypothesized that EI of different soil moistureranges were negatively related to S-index which means the plants required energy to uptake the soil water in the soils with high S-index, is lower than the soils with poor physical quality (less S-index). So we examined our hypothesis in medium to coarse-textured soils of Khorasan-Razavi province (Iran).
This research was conducted in Torogh Agricultural and Natural Resources Research and Education Station in Khorasan-Razavi province, north-eastern Iran (59° 37' 33"-59° 39' 10" E, 36° 12' 31"-36° 13' 56" N). Soil textures of this research station, are classified into loam, silt loam, silty clay loam, clay loam, and sandy loam which is as the same in more than 90% of agricultural soils in Khorasan-Razavi province. Thirty points with different soil textures and organic carbon contents were selected. In order to measure different properties of the soil, two soil samples (5 cm diameter × 5.3 cm length core sample and a disturbed soil sample) were collected from 0-30 cm depth of each point. After conducting required laboratory and field measurements using standard methods, the Soil Moisture Release Curve (SMRC) parameters (RETC program), S-index, PAW and LLWR (measured in matric heads of 100 and 330 cm for the field capacity), IWC and EI of mentioned soil moisture ranges were calculated. In this regard, integration calculations were done by Mathcad Prime 3 software. Finally, the relationships between the measured properties and EI values (for PAW100, PAW330, LLWR100, LLWR330 and IWC) were analyzed using Pearson correlation coefficient and stepwise multivariate linear regression by JMP (9.02) statistical software.
The S-index of 30 soil samples were between 0.029-0.070 with average of 0.046. These results showed that 90% of studied soil samples had good and very good and 10% had poor physical quality. The lowest average EI values of different soil moisture ranges were observed in sandy loam and silt loam and the highest was observed in silty clay loam soil textures. The EI(IWC) mean value was lower than EI(PAW) and EI(LLWR) mean values which indicated that calculating the EI values based on continuous effects of water uptake physical limitations, resulted in lower required energy for plants to uptake the unit mass of soil moisture . Statistical analysis resulted in significantly negative relations between S-index and two indices of EI(PAW100) and EI(IWC). Multivariate regression analysis showed that EI(PAW100) and EI(LLWR100) could be estimated by shape parameter (n) of SMRC by regression coefficients of 0.95 and 0.22, respectively and the value of EI(IWC) could be estimated by S-index and organic carbon content by regression coefficient of 0.57. The parameter of saturated volumetric water content (θvs) of SMRC and sand percentage were determining factors of EI(PAW330). In this research, it was not obtained the significant relationship between EI(LLWR330) values and measured soil physical properties. According to the results, increment of the shape parameter (n) of SMRC and S-index led to reducing the plants required energy to uptake the unit mass of soil moisture in PAW100 and IWC ranges. We found that EI of different soil moisture ranges could be used to evaluate the soil physical quality between the soils with equal soilmoisture contents.
This Research investigated the relationship of PAW, LLWR and IWC EI values with soil physical properties and S-Index in medium to coarse-textured soils. The results indicated that increment of S-index led to decreasing EI(PAW100) and EI(IWC) indices. According to the results, the shape parameter of SMRC and S-index could be accounted for determining factors of EI(PAW100) and EI(IWC) indices values.

This study aimed to investigate the role of calcium in formation of nut and preventing loss of nuts in pistachio cv. Abbasali. Four calcium compounds including calcium nitrate (3/1000), chelate calcium EDTA (1/1000), nano chelate calcium (1/1000) and chelate calcium amino acid (1/1000) were sprayed five times on foliage of 20 years old trees in pistachio garden of Binalud- Neishabor Agricultural Company. The experiment was in factorial based on randomized complete block design with three replications, carried out for two years (2012-2013). Foliar fertilization was started at the end of pollination and repeated for five times with ten days intervals. The results showed that the effects of calcium compound, number of sprayings and interaction of them were not significant on number of nuts per cluster. The effects of calcium compounds were significant on percentage of kernel, splitting and leaf calcium at 5% and on percentage of fruit calcium at 1% levels of probability. Calcium nitrate with 0.16% and nano chelate calcium with 0.13%, had the highest and lowest of fruit calcium contents, respectively. Interaction effects of chelate calcium amino acid and five times spraying were significant on ounce (p ≤ 0.01). The effect of year was also significant (p ≤ 0.01) on number of nut per cluster, percentages of blank fruits, splitted fruits and leaf calcium content. Generally, chelate calcium EDTA with five time applications had the most effects on ounce, and percentages of kernel and leaf calcium content.

Intoduction: Plant growth promoting rhizobacteria (PGPR) are a diverse group of bacteria consisting different species like Pseudomonas, Azotobacter, Azospirillum, Flavobacterium, Bacillus and Serratia with ability of enhancing plant growth and yield by different mechanisms. Flavobacteria are aerobic, gram negative, rod shape bacteria with more than 100 species living in different habitats ranging from soil and water to the foods. There are reports indicating that Flavobacteria are of dominant rhizosphere bacteria with beneficial effects on agricultural crops. Studies in Iran showed that six species of Flavobacterium were isolated and identified from rhizosphere of wheat. The aim of this study was to evaluate the effect of four strains of Flavobacterium on growth and yield of wheat under field conditions.
In this study four strains of Flavobacterium F9, F11, F21 and F40 were used. Bacterial strains were propagated in liquid NB growth medium and were used in field experiments. Fields were prepared in Khorasan Razavi, Khuzestan, Fars, Mazandran and Kermanshah and wheat seeds were inoculated with strains and sowed in a randomized complete block design (RCBD) with five treatments (four strains and a un-inoculated control) with four replications. Wheat varieties were Pishtaz in Khorasan and Fars, Marvdasht in Kermanshah, Chamran in Khuzestan and Milan in Mazandaran. Chemical fertilizers were used based on soil analysis. The rate of inoculation was 10 ml of bacteria per kg of seed. Plants were harvested at the end of the experiment and seed yield, total shoot biomass, 1000-seed weight, plant height, number of panicles per m2, number of seeds per panicle and panicle length were measured. Data analysis was performed by SPSS software, and the means were compared at α꞊5% by Duncan test.
Results of the study showed that bacterial strains increased growth and yield of wheat in all provinces. In Mazandaran, all strains promoted seed yield although the effect of F21 was not significant. F40 had the highest effect on factors measures in the study. In Khuzestan, inoculation had no significant effect of seed yield production, although yield production was increased compared to control treatment. There was a similar trend regarding to other factors. In Khorasan, all factors were increased except for seed yield and 1000-seed weight due to inoculation with Flavobacterium strains. In Fars, inoculation with strain F40 significantly increased seed yield production by 11.5% compared to control treatment. In Kermanshah, seed yield, total biomass and plant height were significantly affected by inoculation with bacterial strains. Results showed that strain F40 was the most effective strain to increase yield of wheat. This study showed that Flavobacterium as a PGPR bacteria is able to positively affect the growth of wheat in Iran. This is in agreement with experiments in other parts of the world. In Khuzestan, bacteria were not effective on growth of wheat probably due to high soil temperature in this province compared to other provinces.
This study revealed that Flavobacteria are present in rhizosphere of wheat in Iran and could improve growth characteristics and yield of wheat in field experiments. Finally, strain F40 was the superior strain which increased seed yield by 15 % compared to control treatment.

World cereal demand is growing at the present in accordance with the global expansion of human populations.Bread wheat is the most widely grown cereal grain with 65% (6.5 million hectares) of the total crop cultivated area in Iran. Deficiency of micronutrients in cereal cropping is one of the major worldwide problems. Zinc (Zn) is an essential micronutrient for plants. It plays a key role as a structural constituent or regulatory co-factor of a wide range of different enzymes and proteins in many important biochemical pathways. Nearly half of the world’s cereal-growing areas are affected by soil zinc deficiency, particularly in calcareous soils of arid and semiarid regions. High pH levels and bicarbonate anion concentration in these soils are the major factors resulting in low availability of Zn. About 40% of the soils, used for wheat production in Iran are Zn-deficient, which results in a decrease in growth and wheat grain yield under field conditions. Although application of zinc fertilizers is a common practice to correct Zn deficiency, growing varieties with high Zn efficiency has been reported to be a more sustainable approach. There is significant genetic variation both within and between plant species in their ability to maintain significant growth and yield under Zn deficiency conditions. Plant response to Zn deficiency and Zn fertilization are two distinct concepts. Knowing about these variations, can be very essential and useful for making correct fertilizer recommendation.
In order to investigate Zn efficiency in various wheat genotypes, a factorial experiment as a randomized complete block design was carried out with three replications in agricultural research center of Khorasan razavi (Torough Station), during 2009-2011. Treatments consisted of two levels of Zn fertilizer (0 and 40 kg/h as ZnSO4) and six genotyps of wheat including: three cultivars and one line of bread wheat (Alvand, Falat, Toos, and C75-5 respectively), two species of wheat known as Thriticosecale and Durum. The plot size was 9*3.6 (32.4 m2). Soil fertility status showed 0.05% nitrogen, 7.2 mgkg-1 phosphorus, 180 mgkg-1 potassium and 0.52 mgkg-1 DTPA extractable zinc. At defined phonological stage (SG6 based on Fix’s Index) Zn concentration in shrub was measured. Also grain yield and Zn uptake by grain were determined at the end of ripening stage. Zinc use efficiency, agronomic efficiency and apparent recovery efficiency were calculated according to “Graham, et al.”, “Craswell and Godwin” and “Raun and Johnson” respectively. Zinc use efficiency can be defined as the ratio of grain yield or shoot dry matter yield produced under Zn deficiency to that produced under Zn fertilization.
Grain yield is the most integrative trait of a particular genotype. The results showed that Zn application increased significantly grain yield by 12.61% in comparison with control. This result is supported by Ziayeian and Malakouti (1999). Who reported that Zn application significantly increased the wheat yield (17%). In our research the highest grain yield increase due to Zn application was found in durum wheat (23.5%), and the lowest grain yield increase, were found in Toos cultivar (1.3% yield increase). Cakmak and et al (1997) also obtained more yield with the application of zinc in durum wheat. Application of Zn increased Zn concentration and uptake in grain, 8.6% and 21.5% respectively. Also, application of Zn significantly increased Zn concentration in shoot (36.5%) over the control. Similarly, Moshiri et al (2010) reported increase of Zn concentration in shoot with application of Zn fertilizer. Zn use efficiency in bread wheat genotype, Durum and Thriticosecale wheat was ranked as: Durum wheat genotypes were different in their response to Zn deficiency and Zn supply. Thriticosecale and Toos were the most Zn efficient genotypes, whereas Durum and C75-5 were the most responding to Zn supply. So, without considering these differences, accurate fertilizer recommendation cannot be achieved. For organic farming and low input agriculture systems in regions similar to this experiment location (Torough Station), Thriticosecale and Toos could be suggested. However, for improvement of wheat grain yield and achieve desired quality in calcareous soil, most of the time, it is necessary to use the Zinc fertilizers.

Despite increasing agricultural production in the last three decades, large part of arable soils in Iran are faced with loss of organic carbon, depletion of nutrients, and soil erosion. It is obvious each of these factors will have a direct impact on soil fertility and production sustainability, and for this reason, it is possible that the continuity of this process lead to environmental problems and reduce agricultural production. In this regard integrated soil fertility management is view beyond the supply of nutrients and consists of methods, which aims to maximize the agronomic efficiency and productivity of crop. Atthe present time, the studies show that due to soil and climatic conditions of the country, in addition to optimal use of nutrients and soil fertility, national programs should focus on improving the efficiency of nutrient management and soil organic carbon. Thus, it will be protected the sustainability of soil and agricultural productivity.

Saffron (Crocus sativus L.) is considered as the most expensive spice in the world. Although Iran has the highest world saffron production, but its yield is less compared with other producing countries. The purpose of this research was to evaluate the effect of potassium and zinc application on flower yield and qualitative characteristics of saffron stigma. This study has been implemented based on the soil analysis results at south of Sabzevar city (in west of Khorasan Razavi province) during growing season of 2012 2013. Experiments had been performed as factorial layout based on a randomized complete block design with three replications. Three levels of potassium (0, 100 and 200 kg.ha-¹) and three levels of zinc (0, 25 and 50 kg ha-¹) was investigated as treatments. The measured responses were fresh weight of flowers and stigma, stigma dry weight and number of flowers for saffron. Then data were analyzed by using SPSS software. The obtained results showed that consumption of potassium has no significant effect on the measured characteristics. But consumption of 200 kg ha-¹ potassium sulfate lad to %5.5 numbers of flowers, %5.6 weights of flower, %10 fresh weight of stigma and %8.5 dry weights of stigma increase in flower number compared to control.
While the impact of different levels zinc consumption were significant on studied trait. Consumption of 25 kg ha-¹ zinc sulfate increased % 65 numbers of flower, %84 weight of flowers, %73 fresh weight of stigma and %150 dry weight of stigma to control. However, by using of 50 kg Zinc sulfate, not only measured characteristics didn’t increase, but also saffron yield was lower than control. As regards the many soils in Khorasan province (more than %80) are faced with zinc deficiency, can be concluded that zinc consumption is so necessary to improve yield of saffron.

This study was conducted to investigate enhancement effects of additives on efficacy of glyphosate at different levels of water hardness on camelthorn control at Abasabad Research Station (Mashhad) during 2009-2010. Two separate experiments were carried out. In the first experiment، Four doses of glyphosate (Rundup SL %41) i. e. 0، 4، 6 and 8 L. ha-1 were separately tank mixed with 0. 1، 0. 25، 0. 5 percent of X-change at three levels of water hardness including 47. 5، 95 and 190 mgL-1 of Mg+2 + Ca+2. In the second experiment، ammonium sulfate at three levels i. e. 0، 3 and 4 percent replaced X-change while other treatments remained intact. Treatments were applied during early May to camelthorn plants. Each treatment was replicated three times. Results revealed that without applying additives to herbicide solution، glyphosate efficacy to reduce plant height was significantly declined at higher levels of water hardiness as ED50 was increased from 2. 478 to 31. 407 L. ha-1. Maximum glyphosate efficiency was observed when X-change was used with concentration of 5%. It could reduce ED50 to 6. 579 L. ha-1 compared to 31. 407 L. ha-1 where no additive was applied at highest level of hardness. Under low and medium ED50، there was no significant difference between xchange and ammonium sulfate.

Changes in soil characteristics can potentially increase or decrease the accumulation rate of soil organic carbon (SOC). This study was conducted to quantify soil salinity and clay content effects on the relationship between soil organic carbon (SOC) and grain yield (GY) of wheat (Triticum aestivum L.) in low and high yield population. To this end، 202 irrigated wheat fields were selected in all parts of the Khorasan Razavi province (NE Iran). The studied fields were divided into low yield population (LYP، GY< 5 Mg ha-1) and high yield population (HYP، GY ≥ 5 Mg ha-1) categories. The results showed that significant relationships existed between SOC content and wheat GY (R2=0. 64، P<0. 01). However، the correlation was stronger in LYP (R2adj =0. 66، P<0. 01) than HYP (R2adj =0. 34، P<0. 01). Each unit increase in the SOC (1g kg-1) on average could increase wheat yield by 286 kg ha-1. The SOC also exhibited a strong positive correlation with GY for soils with clay content < 150 g kg-1، but، when the soil clay content was ≥150 g kg-1، a weak relationship was obtained. Stronger positive correlation was observed between GY and the SOC for ECe ≥ 6 dS m-1 as compared to that for ECe< 6 dS m-1. The results demonstrate that the adverse effect of low clay content and high soil salinity level on wheat GY can be markedly improved by increase in SOC. Considering the prevailing conditions of SOC in Iran and assuming that results similar to this study will be obtained in other parts of the country، increase in SOC by 1g kg-1 could increase irrigated wheat production of Iran by 7. 8%. Nevertheless، the increase in GY depends on SOC content and yield target population.

Use of nitrogen fertilizers has contributed much to the remarkable increase in food production that has occurred during the past 50 years. However, environmental and economic challenges due to nitrogen application in agricultural have increased regard to nitrogen use efficiency (NUE). Studies conducted around the world shows that only half of nitrogen fertilizer inputs is taken up by crops. Unfortunately, in Iran, very little information exists about NUE on a large scale for cereal. However, look at the statistics of nitrogenous fertilizers it can be found that overuse of fertilizers may be due to their low efficiency. Therefore, to estimate of NUE during 10 years (1378-87) was used from partial factor productivity (PFP) for this purpose. The results show that, PFP was 38 kg kg-1 and less than 6 units global average (44 kg kg-1). Obviously PFP must be increased by about 8% in the year until the year 1400 at least it equal global average. Thus, it seems that nitrogen fertilizer management methods at the farm scale are the need to review, to reduce nitrogen losses to the environment. In this regard, improving farm management practices, experiences of other countries and using advanced technologies highly will help. Because most technologies have synergistic effects on plant response to nitrogen, hence they must be applied in an integrated manner.

Environmental and economic problems of urban wastes and increasing loss of soil organic matter have necessitated production and application of fertilizers from municipal waste. Therefore، to investigate the effects of three types of urban municipal solid waste (MSW)، a field experiment was conducted on tomato with the following treatments: sulfurous granular compost with or without thiobacillus bacteria and powdery compost، all at five levels: 0، 15، 30، 45، 60 t/ha. The experimental was factorial with completely randomized block design in three replications and was conducted in Khorasan Razavi province، Iran، in 2008-2010. The results showed that application of MSW compost decreased soil pH، but increased soil electrical conductivity (ECe)، sulfate concentrations in soil solution، and soil organic carbon. With continuation of the experiment، after initial decreas، pH of soils gradually increased. In contrast، soil salinity، sulfate concentrations in soil solution، and soil organic carbon were reduced after the initial increase. The use of sulfurous granular compost (with and without thiobacillus) increased ECe، soil organic carbon، and sulphate concentrations in soil solution and decreased soil pH more than the powdery compost. The highest tomato yield was obtained from the treatment with 45 t/ha MSW. Sulfurous granular MSW was superior to the others، such that the use of this compost increased tomato yield by 40% compared to the control. Also، K and Zn concentrations in tomato leaves increased with increase in the rate of MSW، but Mn concentrations was reduced significantly (P <0. 05).