Agricultural Meteorology
Sepideh Dowlatabadi; Mahdi Amirabadizadeh; Mahdi Zarei
Abstract
Introduction
The sustainable availability of water resources and the qualitative and quantitative status of these resources are threatened by many natural and antropogenic factors, among which climate change plays an important role. Climate change can have profound effects on the hydrological cycle ...
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Introduction
The sustainable availability of water resources and the qualitative and quantitative status of these resources are threatened by many natural and antropogenic factors, among which climate change plays an important role. Climate change can have profound effects on the hydrological cycle through changes in the amount and intensity of precipitation, evapotranspiration, soil moisture, and increasing temperature. On the other hand, the distribution of rainfall in different parts of the world will be uneven. So that some parts of the world may face a significant decrease in the amount and intensity of precipitation, as well as major changes in the timing of wet and dry seasons. Therefore, sufficient knowledge about the effects of climate change on hydrological processes and water resources will be of particular importance. In this research, as the first comprehensive study, the effect of future climate change on the water resources components of Neyshabur-Rookh watershed was investigated by a set of one hydrological model and six General Circulation Models under the RCP4.5 scenario.
Materials and Methods
The Neyshabur-Rookh watershed with an area of 9449 square kilometers is a sub-basin of Kavir-e Markazi-e Iran and a part of the Kalshoor Neyshabur watershed, which is located between of 58 degrees and 13 minutes and 59 degrees and 30 minutes and east longitude and 35 degrees and 40 minutes and 36 degrees and 39 minutes north latitude. The study area with an average altitude of 1549.6 m above sea level and average annual precipitation of 246.83 mm, a mean annual temperature of 13.3 Celsius has an arid to semi-arid climate. For hydrological simulation of the watershed using WetSpass-M model, maps of Digital Elevation Model (DEM), land-use, soil texture, slope, and distribution map of groundwater depth, Leaf Area Index (LAI), and climate data (rainfall, mean temperature, potential evapotranspiration, wind speed and the number of rainy days) per month in 1991-2017 period were used. Then the prepared model was calibrated and validated. The climatic data of six General Circulation Models (GCMs) under the RCP4.5 scenario (Representative Concentration Pathways) were downscaled using the Quantile Mapping Bias-Corrected method. The downscaled GCM models were ranked and weighted in each station according to results of the Leave one out cross validation method and utilized as an ensemble for projecting the near-future climatic conditions of the water resources components of the watershed. By importing the monthly maps of precipitation, average temperature and evapotranspiration in the period of 2026-2052 into the calibrated hydrological model, the hydrological response of watershed to near future climate change was determined and evaluated.
Results and Discussion
WetSpass-M was calibrated by changing the calibration parameters in five hydrometric stations and the compared measured and simulated streamflow. The values of four evaluation criteria NS, R2, MB, and RMSE indicated the good performance of the model during the calibration and validation process. By predicting climatic parameters in near future and preparing and importing maps of monthly precipitation, mean temperature, and evapotranspiration to WetSpass-M, the hydrologic simulation of the watershed was done in the 2026-2052 period. The results indicated that the mean annual temperature and precipitation would be respectively increased by 4.66% and 1.21°C under RCP4.5 in the near-future period compared to the baseline period. The average temperature will increase in all months so that the most changes will occur in September and the least changes will occur in March. The rainfall of the watershed will increase in March, April, May, October, and December and will decrease in the rest of the months. The highest and lowest rainfall changes will happen in April and August, respectively. The analysis of the components of water resources in the near future shows that annual total runoff, groundwater recharge, and actual evapotranspiration will increase by 5.9%, 14.85%, and 1.42% compared to the base period, and annual direct runoff and interception will decrease by 15.15% and 3.54%, respectively.
Conclusion
Considering the importance and major role of the Neyshabur watershed in the economy of agricultural products of Razavi Khorasan province, the results of this research will be of great help to the managers and policymakers of the country's water resources management in order to make appropriate decisions with the aim of reducing the effects of climate change on the water resources of the Neyshabur-Rookh Basin.
shahrzad karami; mehdi zarei; jafar yasrebi; najafali karimian; s.Ali Akbar Moosavi
Abstract
Introduction: Heavy metals such as cadmium (Cd) are found naturally in soils, but their amount can be changed by human activities. The study of the uptake and accumulation of heavy metals by plants is done in order to prevent their threats on human and animal’s health.Cadmium is a toxic element for ...
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Introduction: Heavy metals such as cadmium (Cd) are found naturally in soils, but their amount can be changed by human activities. The study of the uptake and accumulation of heavy metals by plants is done in order to prevent their threats on human and animal’s health.Cadmium is a toxic element for living organisms. Cadmium competes with many of nutrients to be absorbed by the plant and interferes with their biological roles. Water stress affects the cell structure and the food is diverted from its normal metabolic pathway. It also reduces the availability and uptake of nutrients by the plant. One reason for the reduction of plant growth under drought stress is the accumulation of ethylene in plants. There are ways to mitigate the negative effects of drought stress that one of which is the use of Plant Growth Promoting Rhizobacteria(PGPRs) to increasing the availability of nutrients. Soil beneficial bacteria play an important role in the biological cycles and have been used to increase plant health and soil fertility over the past few decades.The aim of this study was to investigate theeffect of PGPRson the concentration and uptake of macro nutrients by corn in a Cd-contaminated calcareous soil under drought stress.
Materials and Methods: A greenhouse factorial experiment was conducted in a completely randomized design with three replications. The treatments were two levels of bacteria (with and without bacteria), four levels of Cd (5, 10, 20, and 40 mg kg-1), and three levels of drought stress (without stress, 80, and 65% of field capacity). The pots were filled with 3 kg of treated soil. Cd was treated as its sulfate salt in amounts of 5, 10, 20, and 40 mg kg-1. The soil was mixed uniformly with 150 mg N kg-1 as urea, 20 mg P kg-1 as Ca (H2PO4)2, 5 mg Fe kg-1 as Fe-EDDHA and 10, 10 and 2.5 mg Zn, Mn and Cu kg-1, respectively as their sulfate salt in order to meet plant needs for these nutrients. Six seeds of Zea mays (var. HIDO) were planted at each pot. Each seed of maize was inoculated with 2 mL (1×108 colony-forming units (cfu) mL-1) of Micrococcus yunnanensis (a gram positive bacterium with the ability of production of sidrophore and phosphate dissolving characteristic). Each pot was irrigated daily with distilled water to near field capacity by weight, until 15 days after corn planting. Then corn was thinned to 3 plants per pot and irrigation was started with different levels of drought stress (without stress (F.C), 80, and 65% of field capacity) by weight. At harvest (8 weeks after planting), the aerial parts of the plants was cut at the soil surface. The harvested plants were washed with distilled water, dried to a constant weight at 65C. Representative samples were dry-ashed and analyzed for macro nutrients.
Results and Discussion: The results indicated that the inoculation of bacteria increased shoot dry weight (DW) and total uptake of nitrogen (N), phosphorus (P), and potassium (K). Drought stress decreased DW, total uptake of N, P, and K, concentrations of N and K in corn shoots, and concentration of K in the soil. The application of biological fertilizers, such as plant growth promoting rhizobacteria, increase plant growth through increasing microorganism’s activities and population in the soil and so increase macro nutrients uptake by the plant. Phosphate solubilizing rhizobacteria increase plant growth and phosphate availability with production of organic acids and secretion of phosphatase enzymes or protons and conversion of non-soluble phosphates (either organic or inorganic phosphates) to the forms that are more available for the plants and improve their nutrition and increase their growth. Drought stress decreases Dry Matter Weight(DMW) through decreasing relative humidity of the air of plant growth environment and increases evaporation, transpiration, plant temperature and light intensity of the sun. It prevents normal development of roots, water uptake, and plant growth by reducing the moisture content of the soil. It also decreases uptake and availability of Phosphorus in arid soils because plant growth and root activity in arid soils are lower from those of wetlands and as phosphorus is immobile in the soil, its uptake by the plant will decrease. N concentration of plants will increase drought stress conditions through rapid accumulation of amino acids that had not been converted into protein. The combined effects of drought stress and inoculation of bacteria on decomposition of silicates, cause the release of nutrients such as potassium. Increasing levels of cadmium in both cases, with and without bacterial inoculation, decreased DW, N and K uptake by corn because of its toxicity and its competition and interactions with these nutrients.
Conclusion: The inoculation of bacteria mitigated the negative effects of drought stress and cadmium contamination by increasing dry weight of corn and increasing uptake of macronutrients by aerial parts. Drought stress in both cases (with and without bacterial inoculation) reduced shoot dry weight, total uptake of macro nutrients, N and K concentrations in corn shoots and post-harvest potassium concentration in the soil. Cadmium levels decreased shoot dry matter and N and K uptake by the plant. The use of bacteria was more effective at low cadmium and drought stress levels.
hamidreza boostani; mostafa chorom; abdolamir moezzi; najafali karimian; naimeh enayatizamir; mehdi zarei
Abstract
Introduction: Zinc (Zn) is an important nutrient element for humans and plants that controls many biochemical and physiological functions of living organisms. Zinc deficiency is common in high pH, low organic matter, carbonatic, saline and sodic soils. Salinity is a major abiotic environmental stresses ...
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Introduction: Zinc (Zn) is an important nutrient element for humans and plants that controls many biochemical and physiological functions of living organisms. Zinc deficiency is common in high pH, low organic matter, carbonatic, saline and sodic soils. Salinity is a major abiotic environmental stresses that limits growth and production in arid and semi-arid regions of the world. Bioavailability of Zn is low in calcareous and saline soils having high levels of pH and calcium. Desorption of Zinc (Zn) from soil as influenced by biological activities is one of the important factors that control Zn bioavailability. Few reports on the effects of salinity on the availability and desorption kinetics of Zn are available. Rupa et al. (2000) reported that increasing the salt concentration led to increase Zn desorption from soil due to ion competition on soil exchangeable sites. Different kinetic equations have been used to describe the release kinetics of nutrients. Reyhanitabar and Gilkes (2010) found that the power function model was the best equation to describe the release of Zn from some calcareous soil of Iran, whereas Baranimotlagh and Gholami (2013) stated that the best model for describing Zn desorption from 15 calcareous soils of Iran was the first-order equation.less attention has been paid to kinetics of Zn release by DTPA extractant over time by inoculation of plant growth promoting rhizobacteria and mycorrhizae fungi in comination with soil salinity.The objective of this study was to evaluate the effect of plant growth promoting rhizobacteria (PGPR) and mycorrhizae fungi (MF) inoculation on release kinetic of Zn in a calcareous soil at different salinity levels after in cornplantation
Materials and Methods: A composite sample of bulk soil from the surface horizon (0-30 cm) of a calcareous soil from southern part of Iran was collected, air dried, passed through 2 mm sieve, and thoroughly mixed. Routine soil analysis was performed to determine some physical and chemical properties. The experiment was conducted in the greenhouse of agriculture college of Shahid Chamran University, Ahvaz, Iran. A factorial experiment as a completely randomized design with three replications was conducted in greenhouse conditions. The first factor consisted of salinity levels (0, 15 and 30 cmol(c) kg-1 salt supplied as a 3:2:1 Na:Ca:Mg chloride salts) and the second factor was microbial inoculation (without inoculation, fungi, bacteria, bacteria + fungi).Soil samples were extracted using DTPA extractant for periods of 0.5, 1, 2, 6, 12 and 24 hours. Cumulative Zn released (q) as a function of time (T) was evaluated using seven different kinetic models. A relatively high values of coefficient of determination (r2) and low values of standard error of estimate (SEE) were used as criteria for the selection of the best fitted models. Statistical analysis of data was done using MSTATC package (Mstatc, 1991). Comparison between means was performed using Duncan's multiple range test (DMRT) at the significant level of P < 0.05. Also, charts were drawn by excel computer package.
Results and Discussion: Investigation of Zn release patterns showed that the control and all treated soils had a uniform pattern of Zn release. Overall, Zn release patterns were generally characterized by an initial fast reaction at first two hours, followed by slower continuing reaction. It seems likely that the release of zinc is controlled by two different mechanisms. Two-step process of releases (rapid and subsequent slow) is attributed to the existence of places with different energy. The use of all microbial treatments increased the initial release of Zn compared to control. The most and the least Zn initial release observed in fungi-bacterial and bacterial treatment respectively. By application of all microbial treatments, Zn release rate declined compared to control and the lowest decrease observed in fungal treatment. In general, Zn initial release was increased and Zn desorption rate was decreased by increasing of salinity levels. Also, soluble and exchangeable forms of Zn had the highest influence on Zn release control.
Conclusions: Results showed that simplified Elovich, two constant rate and parabolic diffusion kinetics models showed good description of the Zn release. Based on the highest correlation coefficient and the lowest mean standard error of the estimate, simplified elovich determined as the best kinetic model. So it seems that the main mechanism controlling the Zn release in the tested soil is diffusion phenomena.
M. Bahraminia; M. zarei; abdolmajid ronaghi; R. Ghasemi
Abstract
A greenhouse experiment was conducted to evaluate the effectiveness of arbuscular mycorrhizal (AM) fungi in phytoremediation of zinc contaminated calcareous soil by vetiver grass. Experiment was a factorial arranged in a completely randomized design (CRD) with three replications. Two factors consisted ...
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A greenhouse experiment was conducted to evaluate the effectiveness of arbuscular mycorrhizal (AM) fungi in phytoremediation of zinc contaminated calcareous soil by vetiver grass. Experiment was a factorial arranged in a completely randomized design (CRD) with three replications. Two factors consisted of Zn levels (10, 150, 300 and 600 mg kg-1 as ZnSO4.7H2O) and AM fungi (control, Glomus intraradices, Glomus versiforme). Shoot and root dry weights decreased as Zn levels increased. Mycorrhizal inoculation increased those plant measured parameters compared to those of control. With increasing Zn levels, and mycorrhizal inoculation, Zn uptake of shoot and root increased. Root colonization with mycorrhizal inoculation increased, but decreased as Zn levels increased. Mycorrhizal inoculation increased zinc extraction, uptake and translocation efficiencies. Zinc translocation factor decreased as Zn levels increased, however inoculation with AM fungi increased it. Zinc extraction and uptake efficiencies of G. intraradices were more than G. versiforme,while zinc translocation efficiency and factor were vice versa.
M. Zarei; Z. Paymaneh; abdolmajid ronaghi; A.A. Kamgar Haghighi; A. Shahsavar
Abstract
Rootstocks are of primary importance to the citrus industry. Rough lemon (Citrus jambhiri L.) is one of major and widely used rootstocks in Citrus production. The experiment was a completely randomized design in a factorial arrangement with three replications. The factors were mycorrhizal treatments ...
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Rootstocks are of primary importance to the citrus industry. Rough lemon (Citrus jambhiri L.) is one of major and widely used rootstocks in Citrus production. The experiment was a completely randomized design in a factorial arrangement with three replications. The factors were mycorrhizal treatments at two levels (inoculation with Glomus mosseae and control) and irrigation treatments in 4 irrigation intervals (2, 4, 6 and 8 days). Water deficit decreased shoot and root dry weights and decreasing effect was more on the shoot. As water deficit levels increased, root colonization, leaf water potential and chlorophyll content decreased, but leaf temperature increased. Arbuscular mycorrhizal fungus increased root colonization, shoot and root dry weights, chlorophyll content and leaf water potential, while decreased leaf temperature in comparison with non mycorrhizal treatments.
E. Malekzadeh; H.A. Alikhani; Gh.R. Savaghebi; M. Zarei
Abstract
Abstract
In this study, interaction between AMF (G. mosseae and Glomus spp., respectively indigenous and non-indigenous of HM-contaminated areas) with Cd-resistant PGPRs (Bacillus mycoides and Micrococcus roseus, indigenous of contaminated areas) on the growth, Cd and nutrient uptake of maize plant ...
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Abstract
In this study, interaction between AMF (G. mosseae and Glomus spp., respectively indigenous and non-indigenous of HM-contaminated areas) with Cd-resistant PGPRs (Bacillus mycoides and Micrococcus roseus, indigenous of contaminated areas) on the growth, Cd and nutrient uptake of maize plant (Zea mays L.) in Cd polluted soil were investigated. With increasing levels of Cd, shoot and root dry weights, shoot Fe and P contents decreased but root and shoot Cd content increased. Root colonization was varied at different levels of Cd and co-inoculation with PGPRs. G. mosseae treatment had greatest amount of shoot and root dry weight, Fe and P of shoot at high concentration of Cd. At the levels of 100 and 200 Cd, in only mycorrhizal treatments, plants colonized by Glomus spp. and G. mosseae had respectively high content of Cd roots. At both levels of Cd, shoot Cd content in co-inoculation of M. roseus and B. mycoides with G. mosseae increased and decreased respectively in comparison with single inoculation of G. mosseae. While, at the levels of 100 and 200 Cd, shoot Cd content in co-inoculation of PGPRs with Glomus spp. respectively increased and decreased/did not significant different compared to single inoculation of Glomus spp. Co-inoculation of G. mosseae and M. roseus, with maximum Cd-accumulated in plant, was the most effective treatment in Cd phytoremediation and stabilization.
Keywords: AM fungi, Plant growth promoting rhizobacteria, Phytoremediation, Cd and maize
M. Zarei; M. Habibnejad; K. Shahedi; M.R. Ghanbarpour
Abstract
Abstract
Major of hydrological systems are very complicated and it is not possible to understand them completely, therefore simplification is necessary to understand or control of a part of the system behavior such as water balance relationships. Hydrological models are simple structure of complicated ...
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Abstract
Major of hydrological systems are very complicated and it is not possible to understand them completely, therefore simplification is necessary to understand or control of a part of the system behavior such as water balance relationships. Hydrological models are simple structure of complicated systems in water cycle in the nature. The first goal of a hydrological model is function predict of complicated system and survey the impact of any kind of changes on system behavior. In this research IHACRES hydrological model was used to daily flow simulation and calculation of rainfall measure that be increase into streamflow, in the kasilian catchment (Area=342.86 km2) and kasilian sub catchment (Area=67.8 km2). The results was representative of delay naught between rainfall and flow in two catchments, also to values of two parameter coefficient of determination (D) and average relative parameter error (ARPE), the model streamflow in kasilian catchment more accuracy simulated than kasilian sub catchment. Altogether, in attention to values of error in flow volume (Bias), average of simulated streamflow by IHACRES model was more than observed streamflow in these catchments. Percentage of rainfall that bears hand to streamflow creation of kasilian catchment was calculated near third of catchment rainfall average and in the kasilian sub catchment for evaluation and calibration period 231 and 216 mm/yr, respectively.
Keywords: Hydrological Model, IHACRES, Calibration, Evaluation