دانشگاه فردوسی مشهدآب و خاک2008-475731420171023Effect of Biochar Types and Rates on Some Soil properties and Nutrients Availability in a Calcareous Soilتأثیر نوع و مقدار بیوچار بر برخی ویژگیهای خاک و قابلیت استفاده بعضی عناصر غذایی در یک خاک آهکی123212463858710.22067/jsw.v31i4.61298FAندا مرادیدانشگاه ارومیهمیرحسن رسولی صدقیانیارومیهابراهیم سپهرارومیهJournal Article20161225Introduction: Biochar is a material produced from organic matters under high temperature and low oxygen conditions. In recent years, scientific attention has been focused on its effects on soil amendment and ecological restoration.Due to its properties related to surface area and porosity, bulk density, nutrient content, stability, cation exchange capacity (CEC), pH value, and carbon content, biochar has the potential to improve physical and chemical soil properties and thus improve crop productivity and contribute to carbon sequestration. Biochars can have very different properties depending on the feedstock they are produced from and the pyrolysis conditions used to generate them.Biochar retains nutrients for plant uptake and soil fertility. The infiltration of harmful quantities of nutrients and pesticides into ground water and the runoff that erodes the soil and enters into the surface waters can be limited with the use ofbiochar. The actual effects of biochar on soil properties depend on the soil type and the plant species grown on the area of application, as well as biochar type and application rate.The aim of this study was to evaluate the effect of the biochar types and rates on some soil properties and nutrient availability in a calcareous soil.
Materials and Methods: An incubation experiment was conducted in a completely randomized design with three replications. The treatments were three type of biochar (apple pruning wastes, grape pruning wastes and wheat straw), and five biochar rates (0, 1, 2, 4 and 8% w/w). Biochars used in the experiment wereproduced at the final temperature of approximately 350°C for almost 3 hours. The biochars were ground and sieved over 1 mm sieve for the incubation experiment.100 g of soil sample was weighed into polyethylene pots and then thoroughly mixed with 1, 2, 4 and 8 g of the biochar samples. Soil controls were run without any amendment. Distilled water was added to the soil–biochar mixtures (soil samples) in order to keeptheir moisture content to 60% of their water-holding capacity. The incubation was carried out in a controlled incubation chamber at 25oC for incubation in aerobically controlled non-leached conditions during 8 weeks.After 60 days, the samples were dried andsoil pH and electrical conductivity (EC) were determined in 1:5 soil to water extracts. Also, to determine mineral N, the soil samples with biochar were extracted with 2 M KCl. Organic matter was determined by dichromate oxidation. Soil extractable P and K were extracted with 0.5 M NaHCO3 (ratio 1:10) (Olsen-P) and 1 N NH4Ac (1:20) (NH4Ac-EK), respectively. DTPA-extractable Fe, Mn, Cu, and Zn were analyzed by atomic absorption spectrometry method (Shimadzu AA-6300).
Results and Discussion: The results indicated that adding biochar changed some soil properties such as soil organic carbon, pH, electrical conductivity and the availability of some macro and micro nutrients. These changes were also more evident with increasingin the rate of biochar. Soil organic carbon (SOC) contentsin the amount of 8% apple pruning wastes, grape pruning wastes and wheat straw biochar were 3.78, 3.80 and 5.24 times more than control, respectively. Available potassium and phosphorus increased further in derived biochar from wheat straw in the amount of 8% compared with apple pruning and grape pruning wastes. Soil available potassium in wheat straw biochar was 2.19 and 1.88 times higher than apple pruning and grape pruning wastesbiochars, respectively. Wheat straw biochar greatly increased soil EC compared to control, and a higher biochar addition finally resulted in a higher value of soil EC. Also, the mineral – N, comprising of ammonium nitrogen (NH4-N) and nitrate nitrogen (NO3-N), concentrationshowed significant reduction when different rates of biochar were added to the soil. Increase in the rate of applicationmarkedly reduced the concentration of both NH4-N and NO3-N. Wheat straw biochar significantly reduced available iron. Also, soil available copper significantly decreased by increasing the rate of biochar. But, soil available manganesesignificantly increased by increasing the rate of biochar. The type and rate of studied biochars had no significant effect on available Zn.
Conclusions: Generally, the soil organic carbon (SOC) markedly increased with an increase in rate of application ofbiochar during the 60 days of incubation. This suggests that the biochar has great potential for carbon sequestration in soil.In conclusion, it became clear that in order to allow for accurate prediction of the effects ofbiochar on soil characteristics and nutrient availability, a deeper understanding of interactions between soil type, biochar production method, biochar feedstock, application rate and field crops is essential. Further research is needed to determine long term impacts of biochar on these soils.تجزیه حرارتی ضایعات گیاهی و تبدیل آن به بیوچار و افزودن به خاک علاوه بر ترسیب کربن و کاهش آلودگی هوا میتواند سبب اصلاح برخی ویژگیهای خاکهایآهکیشود. به منظور بررسی تأثیر بیوچار بر برخی ویژگیهای خاک آهکی،آزمایشیبهصورت فاکتوریل در قالب طرح کاملاًتصادفی اجرا گردید. فاکتورهای آزمایش شامل نوع بیوچار (ضایعات هرس سیب، هرس انگور و کاه و کلش گندم) و مقدار بیوچار (صفر (B0)، 1 (B1)، 2 (B2)، 4 (B4) و 8 (B8) درصد وزنی/وزنی) بودند.نمونههابهمدت 60روزدردمای 25 درجه سانتیگراد و 60 درصد رطوبت ظرفیت زراعینگهداریشدهوسپسویژگی-هایخاکشامل pH، قابلیتهدایتالکتریکی (EC)،مقدارکربنآلی،نیتروژن معدنی،پتاسیم، فسفر،آهن،منگنز،رویومسقابلاستفادهخاکدرآنهااندازه-گیریگردید.نتایجنشانداد،بهطور کلی با افزایش مقدار بیوچار ، کربن آلی خاک،و همچنین شکلهای قابل استفاده پتاسیم ، فسفر ومنگنز بهطور معنیدار افزایش یافت.درصد کربن آلی خاک در تیمار B8 ضایعات هرس سیب، هرس انگور و کاه و کلش گندم در مقایسه با شاهد به ترتیب 78/3، 80/3 و 24/5 برابر افزایش نشان داد.همچنین شکلهاینیتروژن نیتراتی و آمونیومی در هر سه بیوچار با افزایش مقدار کاهش یافتند. بیوچارحاصل ازکاه و کلش گندمسببکاهشمعنیدار pH و آهن قابل استفادهخاک و افزایش قابلیت هدایت الکتریکیخاکگردید. بهطور کلی بیوچار حاصل از کاه و کلش گندم بیشترین تأثیر را بر خصوصیات خاک و قابلیت استفاده عناصر غذایی داشت.https://jsw.um.ac.ir/article_38587_e7f9c41608fb85cb37c2dcea7bcfff25.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Experimental Investigation Anisotropy Permeability of Uniform Coarse Grain Soilsبررسی آزمایشگاهی نفوذپذیری ناهمسانگرد خاکهای درشت دانه یکنواخت124712593858810.22067/jsw.v31i4.61410FAفاطمه پیشروعلوم و فنون دریایی خرمشهرمرتضی بختیاریعلوم و فنون دریایی خرمشهرنیما شهمی کرم زادهدانشگاه علوم و فنون دریایی خرمشهرJournal Article20161228Introduction: Investigation of water passing through soil is one of the most important problems in soil mechanics and environmental engineering. It is an important parameter for predicting the movement of water and contaminants dissolved in the water through the soil and measured on soil samples in the lab and sometimes tests carried out in the field. Soil permeability generally depends on two factors, the first one is soil Specifications contains an empty space of soil, surface roughness of solid particles, saturation, and another one is characteristics of the fluid (water) that passes through soil. Already few efforts have been made to recognize the characteristics of anisotropy in the geotechnical designs therefore this study has been done. Physical and mechanical properties of soils and sedimentary rocks are generally heterogeneous and hydraulic conductivity (k) is not an exception. The anisotropy of hydraulic conductivity of soils has a great influence on the fluid flow and the transmission of contamination. Knowing the hydraulic conductivity in cases such as flow through dams and dikes, internal erosion in soil masses, settling of consolidated clay levels, optimal design of water and oil wells, and the design of drainage systems for roads, airports and agricultural land. Generally, the hydraulic conductivity is more in the horizontal direction than the hydraulic conductivity in the vertical direction, and the hydraulic conductivity anisotropy is shown with a non-dimensional parameter rk which is equal to the ratio of the horizontal hydraulic conductivity to the vertical hydraulic conductivity. According to Chapuis et al. (1989), on more than 100 measurements of hydraulic conductivity along with the results of the experiments of Chapuis et al. (1990), Rice et al. (1970) and Leroueil et al. (1990), the anisotropy of the hydraulic conductivity of clays, sands and sedimentary rocks are almost like each other. The degree of anisotropy may depend on the shape of the particles, their arrangement, or the orientation of the free space among the particles of the soil, which appears to be less than 4. Due to the impossibility of preparing intact samples from grain materials, as well as the lack of suitable measuring instruments for grain samples, there are few valid results for non-sticky materials. As Chapuis et al. (1989) and Sferlazza et al. (2009) in accordance with most of the experimental results, the anisotropy of hydraulic conductivity increases with density, and also the degree of anisotropy decreases with increasing porosity ratio.
Materials and Methods: In order to conduct the present research, measurement device was designed and built. This device is a cube with 150 mm ×150 mm × 173 mm dimensions. The components of the device are: bleeding valves, inlet and outlet valves, porous plates and the size of the sample respectively. In this study, four uniform soil samples were selected for test. Samples are prepared in falling manner, with three porosity and under three different hydraulic gradient were tested. In Table 1 The general pattern of research experiments is presented. In this study, 36 tests were performed.
Table 1-Pattern of research experiments
Parameter Diameter particle Void ratio Water head
The number of test cases 4 3 3
To measure vertical permeability, due to large grains samples, according to ASTM D-2434 standard fixed-load test method has been used. First, the porous plate is placed on the bottom of the measuring device to prevent the soil from entering and exiting the water penetration then The soil is inserted from the fixed height into the device and the porous plate is placed on the sample. Then place should be located at the top of the device and close the screws so there should be no water leak. Then the weight of the soil should be measured and connect the system to the water. Then the outlet tap should be opened and water should be passed through the soil sample until the sample would be completely saturated and no air bubbles come out of the outlet pipe and fix water level. Then the water head and weigh the empty container and the duration of the outflow of water for a given water volume should be measured. After performing the test at a specified head, the elevation of water should be changed by reservoir adjustment and the permeability coefficient would be measured in other loads.
Results and Discussion:
The effect of hydraulic loads on horizontal and vertical hydraulic conductivity coefficients for uniform samples
Horizontal and vertical hydraulic conductivity tests were performed on uniform samples including coarse aggregate materials with a diameter of 0.85, 2, 6.35, and 5.9 mm. In Figures (1) to (3), the effect of hydraulic load on horizontal and vertical hydraulic conductivity for uniform samples in minimum and maximum conditions is shown.
(B( (A(
(D( (C(
Figuer1- According hydraulic conductivity to hydraulic gradient for uniform samples with A) vertical hydraulic conductivity, minimal porosity B) Horizontal hydraulic conductivity, minimal porosity C) vertical hydraulic conductivity, maximum porosity D) horizontal hydraulic, maximum porosity
Investigations showed that in all cases, with increasing hydraulic load, the horizontal and vertical hydraulic conductivity decreased and then the process of change was almost constant.
Investigation of the effect of porosity on horizontal and vertical hydraulic conductivity of uniform samples
The results showed that the horizontal hydraulic conductivity coefficient for all samples was higher than the vertical hydraulic conductivity coefficient.
Also, the results showed that the minimum hydraulic conductivity (e = 0.46) and maximum porosity (e = 0.97) were about 34.33 and 0.35 percent higher than the hydraulic hydraulic conductivity, respectively.
Investigation of the effect of porosity on the anisotropy coefficient of hydraulic conductivity of uniform samples: The results showed that with increasing porosity, the coefficient of heterogeneity of hydraulic conductivity for uniform samples was reduced and this coefficient was for uniform samples in the range of 0.89 to 1.35.
Conclusions: The final results can be summarized as follow:
1. The permeability in the horizontal direction is often greater than the permeability in the vertical direction.
2. The anisotropy permeability for uniform sample is between 0.85-1.35.
3. The anisotropy permeability decreases with increasing porosity.
4. In the uniform samples, maximum permeability occurs at higher hydraulic conductivity.
5. With increasing the uniformity coefficient, the amount of hydraulic conductivity decreases.بررسی آب عبوری از خاک یکی از مسائل بنیادی در مکانیک خاک و مهندسی محیط زیست است. هدایت هیدرولیکی اثر مهمی بر مشکلات تراوش، تحکیم و پایداری دارد که جزء مهمی از طراحی و تحلیل مهندسی خاک و سنگ را شکل میدهد. به منظور انجام تحقیق حاضر، اقدام به طراحی و آزمایش دستگاهی برای اندازهگیری هدایت هیدرولیکی افقی و قائم درنمونه ذرات درشتدانه یکنواخت شده است. در تحقیق حاضر چهار نمونه خاک با قطر 85/0، 2، 35/6 و 5/9 میلی متر برای آزمایش انتخاب گردیده است. اثر تغییرات تخلخل و بار آبی بر میزان ناهمسانی هدایت هیدرولیکی بررسی شده است. نتایج حاصل از تحقیق نشان میدهد میزان ناهمسانی با افزایش تخلخل کاهش مییابد. همچنین با افزایش هدایت هیدرولیکی جریان از حالت لایهای خارج میگردد. هدایت هیدرولیکی در جهت افقی اغلب بیشتر از هدایت هیدرولیکی در جهت قائم است. میزان ناهمسانی هدایت هیدرولیکی محدوده بین 85/0 تا 35/1 را دربر میگیرد.https://jsw.um.ac.ir/article_38588_724d6c26d65723c301fe0f390d302269.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Copula-Based Regional Drought Analysis and Derivation of Severity-Area-Frequency Curve in Lake Urmia Basinتحلیل منطقهای و استخراج منحنی بزرگی- مساحت- فراوانی خشکسالی با استفاده از توابع مفصل در حوضه آبریز دریاچه ارومیه126012773858910.22067/jsw.v31i4.60382FAمجید منتصریدانشگاه ارومیهبابک امیرعطاییدانشگاه ارومیهحسین رضاییدانشگاه ارومیهJournal Article20161117Introduction: Drought is a natural phenomenon and was described when precipitation is less than expected. Since the precipitation amounts in terms of spatial and temporal characteristics are different from one region to another, so this phenomenon is known as a multivariate phenomenon. This phenomenon often characterized by different variables such as drought duration, severity, intensity and spatial extent. Although site specific analysis can provide useful information on drought occurrences in a limited area, but these results have a fundamental uncertainty to drought risk assessment in a large region. Therefore regional drought analysis, provides a more comprehensive assessment in each region, and is essential for short and long term management of water resources. Meanwhile, the copula functions has been developed as a new advanced technique for modeling the two or multivariate joint probability distribution in different fields such as financial, hydrology, water resources and risk management. So, in this research, regional analysis of drought severity and percent of drought area were performed using the copula functions in Lake Urmia basin, as one of the Iran's drought-prone basin. Such study with emphasis on bivariate analysis of drought severity and drought areal extend were conducted for the first time in the study area. The main objectives of this study are: 1) Modeling drought characteristics in Lake Urmia basin, 2) Evaluation of copula functions in modeling the structure of the region's drought characteristics, and 3) Develop the Severity-Area-Frequency curve using the appropriate copula.
Materials and Methods: Copula is the stochastic model and based on probability. In other words, copulas are function for modeling the two or multivariate random variables. Copulas can be easily coupled the marginal distributions to multiple distributions. There are many parametric copula families available, that seven copula functions such as archimedean (Clayton, Frank, Gumbel and Joe), extreme value (Galambos), elliptical (Normal) and others (Plackett) were used. The SPI-1 was determined at each station and then, the whole area was divided into small grids with cell size of 2000×2000. Distances between the grid centers with all the selected stations were calculated with a programming code. Finally, the SPI values in each grid were calculated using IDW method. The severity and percentage of drought area variables were determined and used for regional drought modeling in the study area based on drought threshold equal to zero. After determining the best statistical distribution of two variables, the appropriate copula function was conducted based on different goodness of fit tests. Finally, the Severity-Area-Frequency curve for the study area was developed based on the appropriate copula function and conditional return periods.
Results and Discussion: The correlation between the two variables of percentage of drought area and severity was assessed using different graphical (Kendall plot and Chi plot) and statistical tests (Spearman rand order correlation and Kendal tau). The results showed a positive correlation between the drought severity and percentage of drought area variables. Based on Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) and graphical test, the Lognormal and Beta probability distributions were select as a best fit distribution of severity and percentage of area under drought, respectively. Finally, the Frank copula among other type of copulas was selected as an appropriate copula for modeling joint drought severity and percentage of area under drought for the study area based on Maximum log likelihood, AIC, BIC and RMSE criteria. The S-A-F curve was developed using conditional return periods based on Frank copula. According to S-A-F curve, it can be seen that increase in the percentage of area under drought in the study area led to increase in drought severity and vice versa. For example, drought severity with return period of 20 years and drought with 20 percent areal extend is obtained equal to 0.37.
Conclusions: Copula functions are of great importance in the analysis of drought, due to preserve correlation between variables and not have any limitation to have a same marginal distribution in long-term prediction of drought events. In this study, using best fit copula (Frank copula) and conditional return periods, the relationships between drought severity and percent of area under drought for the study area named S-A-F curve were developed. These curves can be useful for planning and management of drought in the region. Drought risk assessment based on the results of this study can be high priorities for drought monitoring in large areas.خشکسالیها رویدادهای کرانهای هستند که براساس تداوم در زمان و تاثیرات مکانی آن مشخص میشوند. بطورکلی خشکسالیهای منطقهای متاثر از گردش عمومی جو (در مقیاس بزرگ) و عوامل طبیعی منطقهای شامل شرایط توپوگرافی، دریاچههای طبیعی، موقعیت نسبت به مرکز و مسیر جریانهای آب و هوایی در جو (در مقیاس ریز) بوده و اثرات کاملأ همسانی در یک منطقه وسیع را نشان نمیدهند. لذا در این مطالعه توزیع احتمال توام بزرگی-مساحت تحت پوشش خشکسالی در حوضه آبریز دریاچه ارومیه با استفاده از تکنیک توابع مفصل انجام پذیرفته و منحنی بزرگی-مساحت-فراوانی/احتمال خشکسالی (S-A-F) توسعه داده شده است. بدین منظور از سری دادههای شاخص خشکسالی یکماهه SPI در 24 ایستگاه هواشناسی در محدوده مطالعاتی و 7 خانواده تابع مفصل شامل کلایتون، گامبل، فرانک، جو، گالامبوس، پلاکت و نرمال برای مدلسازی توزیع احتمال توام دو متغیر همبسته بزرگی و مساحت تحت پوشش خشکسالی استفاده شده است. عملکرد توابع مفصل هفتگانه مذکور براساس معیارهای آماری رایج مورد آزمون قرار گرفته و در نهایت بازای مناسبترین تابع مفصل (مفصل فرانک)، دورههای بازگشت شرطی تعیین و منحنی S-A-F برای منطقه مطالعاتی استخراج شد. نتایج مطالعه نشان میدهد که رفتارهای کرانهای اقلیمی (خشکسالی یا ترسالی) اکثریت محدوده مطالعاتی را تحت تاثیر قرار میدهند. درحالیکه رفتارهای نیمه یا شبهخشک دارای پوشش مساحت متفاوت با پراکندگی قابل توجه در محدوده مطالعاتی بوده و با افزایش بزرگی خشکسالی مساحت بیشتری از حوضه آبریز را در بر میگیرند. بطوریکه بعنوان مثال، بزرگی خشکسالی برای زمان برگشت 50 ساله با کمترین و بیشترین مقادیر در منطقه یعنی 42/0 و 0/1 بترتیب حدود 5 و 95 درصد مساحت محدوده مطالعاتی را پوشش میدهد.https://jsw.um.ac.ir/article_38589_dd447382bc3ed0e931787138dacd584f.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Estimating BioavailablePhosphorus by Some Chemical Extraction Methods for Algae (Senedesmusobliquus) in Western River Sediments of the Lake Urmia Basinارزیابی فسفر زیستفراهم جلبک (Senedesmusobliquus) با عصارهگیرهای شیمیایی در رسوبات رودخانههای غرب حوضة آبخیز دریاچه ارومیه120012143858510.22067/jsw.v31i4.60469FAحامد ارفع نیادانشگاه ارومیهعباس صمدیارومیهفرخ اسدزادهدانشگاه ارومیهابراهیم سپهردانشگاه ارومیهJournal Article20161121Introduction: Phosphorus (P) is an essential nutrient for all life forms. In aquatic environments, P is a double-edged sword. In some areas, habitat biodiversity is strongly limited by low P bioavailability, while in others, P inputs in excess of plant needs have led to pollution of water bodies and eutrophication. There is little information available on P status in river sediments by single chemical extraction and its correlation with algae growth in Iran. This study was performed to select proper single chemical extraction methods by algal bioassay. The quantity of P estimated by different extractions methods depends on sediment characteristics such as calcium carbonate, pH, clay and organic matter contents. Therefore, this study was conducted in western rivers of the Lake Urmia to get an insight into P status in sediments by using single chemical and biological P assay.
Materials and Methods: The lakeUrmia basin has the second largest water resources in Iran with Mediterranean climate. Italso has the largest hypersaline lake in the world. There is a significant phytoplankton growth and also some dense algal blooms occurring during years with low salinity in wetlands and lagoons. Thirty four river sediment samples from seven main rivers of the Lake Urmia basin were collected from depth of 0-10 cm to evaluate algae (SenedesmusObliquus) P bioavalability by single chemical extraction. Selection of extractantis based on different mechanism of extraction. Cluster analysis was conducted on 17 sediment samples selected for algal bioassay.Pearson simple correlation and multivariate analysis were also performed.
Results and Discussion:Average total P concentrations of the sediments were343-654, 456 mg kg-1. Sodium bicarbonate 0.5 Mextractable P (Olsen-P) varied from 0.48 to 8.42 mg kg-1. Sediments from upper reach had considerably higher total and bioavailable P concentration in comparison with lower reach sediment. The low reach sediments of two rivers had higher Olsen extractable P than the threshold value of 20 mg kg-1indicating possible release which poses a threat to aquatic environment.Upper reach sediments had higher restoration potential, but algal bloom was observed in low reach part of rivers, particularly Simineh and Mahabad Chai. Land use changes, discharge of sewage from rural and urban section, industrial activity and cycling of river borne P are the main reasons for algal bloom in wetlands and lagoons around the lake.Principal component analysis (PCA) performed on the data identified three PC which explained 83.3% of total variation and silt and sand had higher loading values. Active calcium carbonate equivalent (ACCE) was negatively correlated with sand in the first PC. Different extractions were positively correlated with each other. The Mehlich III and Olsen-P extraction methods were significantly correlated and the predicted values were same. The average rank order of P extraction by singleextractantswas Cowell >Mehlich III >NaOH 0.1 M > Olsen > Morgan > AB-DTPA > Bray II.Extractants had different long-term and short-term potential to extract algal available P. The Cowell extractable P concentrations of sediments varied from 1.44 to 88.0 mg kg-1.This extractant was correlated significantly with algal growth and selected as the best P single extraction method among allextractants. The high correlation between 0.1 M NaOH and algae growth indicates the sensitivity of P bioavailability to redox conditions in river system. Algae (SenedesmusObliquus) was able to use P from different sediment components because its growth was correlated with Cowell, Mehlich III, NaOH 0.1M, Olsen and Morgan.
Conclusion: Legacy P (sediment P) evaluation by chemical extractants gives new insight into P bioavailability in river sediments of the Urmia Lake. The results of this work showed that Cowell extractant could be used to estimate algal available P in studied river sediments. Similarity between Olsen-P and Mehlich-P in estimating bioavailable P suggests that Mehlich III-P can be substituted for Olsen-P in studied sediments.For sustainable P management, monitoring P status by single chemical extraction methods is necessary. Phosphorous fertilizer application around the Lake Urmia basin lands should be conducted based onthe P soil test to avoid any aquatic pollution. Care must be taken in lower reach river sediments because of fragile ecosystems such as wetlands and lagoons. Further investigations are also needed to evaluate legacy P bioavailability by temporal and spatial variability.فسفر یک عنصر غذایی ضروری برای تمامی جانداران میباشد و در زیستبومهای آبی به شمشیر دولبهای میماند، که از سویی میتواند عامل محدودکننده رشد جاندارن و در شرایط دیگر، موجب آلودگی و ایجاد پدیده سرشارسازی در پیکرههای آبی شود. گزارشهای مکتوب و عینی از پدیده شکوفایی جلبکی در تالابها و رودخانههای غرب دریاچه ارومیه وجود دارد. با توجه به عدم وجود پژوهشی جامع در رابطه با وضعیت فسفر زیست-فراهم در رسوبات رودخانهای در منطقه، این مطالعه با هدف ارزیابی مقدار فسفر زیستفراهم در 34 نمونه از رسوبات رودخانهای و با استفاده از 7 روش عصارهگیری مختلف انجام و روش مناسب عصارهگیری با کاربردآزمون جلبکی تعیین شد. نتایج نشان داد که ویژگیهای فیزیکی و شیمیایی رسوبات و به ویژه بافت آنها دارای دامنهی بسیار وسیعی است. میانگین مقادیر کمّی فسفر استخراج شده با استفاده از روشهای مختلف به ترتیب؛ بری 2 < دی تی پی ای < اولسن < هیدرواکسید سدیم < مهلیچ 3 < کالول بود. آزمون همبستگی موید رابطه معنیدار بین مقادیر فسفر استخراج شده در اغلب روشهای عصارهگیری بود. علاوه بر همبستگی معنیداری(001/0>P، 93/0=r) از نظر کمی مقدار فسفر استخراج شده به روش اولسن و مهلیچ 3 نیز مشابهت داشت. آزمون جلبکی نشان داد که در بین شاخصهای مختلف فسفر زیستفراهم، مقدار فسفر عصارهگیری شده به روش کاول رابطه بسیار معنیداری(001/0>P، 67/0=r2) با جمعیّت جلبک (Senedesmusobliquus) در محیط کشت وجود داشت. در مجموع براساس یافتههای این پژوهش میتوان روش کاول را به عنوان مناسبترین روش ارزیابی فسفر زیستفراهم جلبکی در رودخانههای غرب دریاچه ارومیه پیشنهاد نمود.https://jsw.um.ac.ir/article_38585_c63f4cabf528edbd3f867dffd954ada8.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Evaluation of Spatial Variability of Biological Indicators of Soil Quality in Wheat Farms of Pasargad Plainبررسی پراکنش مکانی شاخصهای بیولوژیک کیفیت خاک در مزارع گندم دشت پاسارگاد124712593858610.22067/jsw.v31i4.60472FAوحید اله جهاندیده مهجن آبادیدانشگاه شیرازعلی داد کرمیاستادیار بخش تحقیقات خاک و آب، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی فارس، سازمان تحقسید روح اله موسویدانشگاه تهران0000-0002-7420-3746هادی اسدی رحمانیموسسه تحقیقات خاک و آب، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایرانJournal Article20161124Introduction:Soil quality as an important part from soil resource sustainability, consistently isinfluenced by human activities.Today, the presence of accurate information about variability of soil quality properties is considered more than ever to apply this information in economic modeling, environmental predictions, accurate farming and natural resources management. Soil quality is defined as: “capacity of the soil to function, within the ecosystem and land-use boundaries, to sustain biological productivity, maintain environmental quality, and promote plant and animal health”; therefore, it is one of the most important factors in developing sustainable land management and sustaining the global biosphere. The definition of soil quality encompasses physical, chemical and biological characteristics, and it is related to fertility and soil health. Many indicators can be used to describe soil quality, but it is important to take into account sensitivity, required time, and related properties, than can be explained. Properties related to organic matter content, such as microbial respiration, microbial biomass carbon (MBC) and enzymatic activity (urease and phosphatases) can be used as soil quality indicators. They provide early information about mineralization processes, nutrient availability and fertility, as well as effects resulting from changes in land use or agricultural practices (e.g. tillage or application of different types of organic matter). In this context, biological properties have been used as soil quality indicators, because of their relationship with organic matter content, terrestrial arthropofauna, lichen, microbial community (biomass or functional groups), metabolic products as ergosterol or glomalin and soil activities as microbial respiration and enzyme production. This study was carried out for evaluation the spatial variability of biological soil quality indicators in wheat farms of Pasargad plain.
Materials and Methods: After reviewing the initial map of Pasargad, a total of 60 samples were provided using a systematic grid square sampling pattern with 500×500 m over the 1200 ha area of Pasargad at surface soil depth (0-30 cm). The characteristics of soil including organic carbon, pH, EC, microbial respiration, microbial biomass carbon , soil alkaline phosphatase and urease enzymes activity, ratio of microbial biomass carbon to organic carbon (MBC/OC) andmicrobial metabolic quotient(qCO2) were measured and calculated. Results were analysed with SPSS, Excel, GS+, and ArcGIS sotwares. Summary statistics were calculated for the 60 samples including mean, maximum and minimum, coefficient of variation (CV), kurtosis and skewness. In addition, Pearson correlation coefficients were calculated for untransformed data. For evaluation of different interpolation methods of soil characteristics in Pasargad plain root mean square error (RMSE), mean bias error (MBE) and mean absolute error (MAE) were used. We also constructed maps of the spatial distributions for each individual variable using best interpolators including kriging, inverse distance weighting (IDW) and cokriging methods.
Results and Discussion; The results showed that in the most cases the studied properties had too much variation. Based on the coefficient of variation, pHand qCO2had the lowest and highest variations, respectively. There was significant linear correlation between most of soil properties. From lognormal transformation was used for normalization of EC and qCO2. Best model for single semivariogram of organic carbon, microbial respiration, urease enzyme activity, microbial biomass carbon, qCO2 and MBC/OC in the soil was spherical model, for pH in the soilwas exponential model and for EC and phosphatase enzyme activity was gaussian model. Also, the best interpolator for pH, EC, organic carbon, microbial biomass carbon, urease activity, qCO2and MBC/OC was kriging, for alkaline phosphatase activity was inverse distance weight, and for microbial respiration was cokriging method. Amount of pH increased from north to south of Pasargad plain, but amounts of EC and organic carbon were inverse of pH.The higher amounts of microbial respiration and urease activity were observed at the south and east, respectively. The amount of phosphatase activity in the soil of Pasargad plain was scattered, and wide area in the plain had the activity between 215-275 µg PNP/g.hr. The higher amount of MBC and MBC/OCand lower amount of qCO2were observed at the west.
Conclusions: The biological soil properties were sensitive and rapid indicators of effects of soil management. Generally, according to the spatial variabilitymap, the areas in the region are critical situations in terms of biological indicators of soil. So the management techniques that are applied by farmers in these areas have to be changed. The results of this study used in the improvement of regional planning for sustainable management of soil.کیفیت خاک ابزاری کارآمد برای ارزیابی عملکردخاک و تغییرات ناشی از مدیریت بر خاک میباشد. برای ارزیابی کیفیت خاک و تغییرات آنها از شاخصهایی بیولوژیک استفاده میشود. این پروژه بهمنظورارزیابی برخی از ویژگیهای بیولوژیک خاک در دشت پاسارگاد بهوسعت حدود 1200 هکتار اجرا شد. بدین منظور پس از بررسی نقشه اولیه دشت پاسارگاد، نقاط نمونهبرداری بهصورت شبکهبندی منظم و با فاصله 500 متر تعیین گردید و تعداد 60 نمونه از عمق سطحی خاک (30-0 سانتیمتر) جمعآوری شد.در بیشتر موارد ویژگیهای مورد مطالعه دامنۀ تغییرات زیادی داشتند. بر پایۀ ضریب تغییرات، pH کمترین و تنفس ویژه بیشترین تغییرات را داشت. همبستگی خطی معنیداری بین ویژگیهای خاک وجود داشت. همچنین، کریجینگ، بهترین میانیاب برای واکنش خاک، هدایت الکتریکی، کربن آلی، کربن توده زنده میکروبی، آنزیم اورهآز، تنفس ویژه و نسبت کربن توده میکروبی به کربن آلی بود. روش وزندهی عکس فاصله برای آنزیم فسفاتاز قلیایی و کوکرجینگ برای تنفس پایه خاک بهعنوان بهترین روش انتخاب گردید. مقدار واکنش خاک از شمال به جنوب افزوده شد اما مقدار هدایت الکتریکی و کربن آلی عکس مقدار واکنش خاک بود. بیشترین مقادیر تنفس میکروبی و آنزیم اورهآز به ترتیب در جنوب و شرق مشاهده گردیدند. مقدار آنزیم فسفاتاز قلیایی در دشت بهصورت پراکنده بود و مساحت گستردهای از دشت مقادیری بین µgPNP/g.hr 275-215 را داشت. بیشترین مقدار کربن توده زنده میکروبی و نسبت کربن توده زنده میکروبی به کربن آلی و کمترین مقدار تنفس ویژه در غرب مشاهده گردید. نتایج این تحقیق در بهبود برنامهریزیهای منطقهای جهت مدیریت پایدار خاک کاربرد دارد.https://jsw.um.ac.ir/article_38586_647107a519f6a52461b464159f8d3cd6.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Application of Fractal Theory to Quantify Structure from Some Soil Ordersکاربرد تئوری فرکتالی در کمّیسازی ساختمان برخی از راستههای خاک در استان فارس117111863858310.22067/jsw.v31i4.57888FAعلی داد کرمیاستادیار بخش تحقیقات خاک و آب، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی فارس، سازمان تحقروح اله زارعبخش خاکشناسی، دانشگاه آزاد اسلامی واحد علوم و تحقیقات فارس، شیراز، ایرانوحید اله جهاندیده مهجن آبادیدانشگاه شیرازJournal Article20160801Introduction: Fractal geometry concepts have been widely applied as a useful tool to describe complex natural phenomena, in particular,for a better understanding of soil physical systems. However, limited information is available on the fractal characteristics of soil properties or soil aggregation. A soil aggregate is made of closely packed sand, silt, clayand organic particles building upsoil structure. Soil aggregation is a soil quality index integrating the chemical, physical, andbiological processes involved in the genesis of soil structure. Soil structure and its stability are important issuesfor many agronomic and environmental processes. Thus, quantitative description of soil structure is very important. Soil forming factors in different soils (various orders) and forms affect the soil structureformation. Characterizing aggregate size distribution for different soil orders using fractal theory is necessary for evaluating the impact of soil forming factors on soil structure and quantifying the relationship between fractal dimension and other important soil properties. Therefore, the aims of this research were quantifying the structure of different soil orders using fractal geometry, mean weight diameter of aggregates (MWD)and geometric mean diameter of aggregates (GMD). In addition, MWD and GMD indices and fractal parameters of soil aggregate size distribution were compared toevaluate soil structure and determinethe relationship between fractal parameters with MWD, GMDand other soil properties.
Materials and Methods: Fractal models which simulate soil structure are also used to better understand soil behaviors. Aggregate size distribution is determined by sieving a fixed amount of soil mass under mechanical stress and is commonly synthesized by the MWD, GMDand fractal dimensions such as the fragmentation fractal dimensions. Therefore, aggregate size distribution and its stability variation were evaluated using some fractal models and MWD and GMD (empirically indices).In the current study, the original data were obtained from analysis of diagnostic horizons of seven important soil orderslocated in Fars Province in the Southern Iran. Soil samples were collected from diagnostic horizons of seven soil orders includingEntisols, Vertisols, Aridisols, Mollisols, Alfisols, Histosols and Inceptisols. The measured physico-chemical properties of soil were aggregate size distribution, soil particle size percentage (sand, silt, and clay), saturation percentage (SP), organic carbon (OC), pH, calcium carbonate equivalent (TNV), gypsum content, soil electrical conductivity (EC) and soil bulk density (BD). The MWD and GMD indices, the fractal dimensions and fractal parameters of aggregates were then calculated. Relationships between soil properties with MWD, GMD and the fractal dimension were also determined.
Results and Discussion: The results showed that there was a significant correlation between fractal dimension of Riue and Sposito and Taylor and Wheatcraft models and soil aggregate stability indices (MWD and GMD indices of aggregates) with the other soil characteristics. This correlation between fractal parameters with organic matter, bulk density, clay and sand percentage was stronger than other soil properties. There was a significant and negative correlation (p< 0.01) between fractal dimension of Riue and Sposito and Taylor and Wheatcraft models with mean weight diameter of aggregates and geometric mean diameter of aggregates. Inverse correlation between fractal dimension and aggregate stability indices illustrateed thatlower fractal dimensionswere calculated for the soils with more stable aggregates which have the highest mean weight diameter of aggregates and geometric mean diameter of aggregates. Subsequently, the fractal dimension of aggregates could reflect the aggregate stability factors. The values of coefficient of determination (R2) and mean error (ME), root mean square error (RMSE), residual some of squares (RSS), mean square of non-fitted (Sr2) and Akaike) AIC (statistical criteria indicated that Taylor and Wheatcraft model had the better performance. Although largerfractal dimensions were estimated by Riue and Sposito modelwhich can be explained by the great model sensitivity, this model overall performed well.
Conclusion: The results indicated that fractal theory can be used to characterize soil structure at different soil orders and fractal dimensions of soil aggregate seems to be more effective in this regard, except forHistosols. Fractal dimension can be estimated using some easily available soil properties. Fractal theory can be applied to characterize and quantify soil structure in different soil orders of Fars Province.ساختمان خاک و پایداری آن با بسیاری از فرآیندهای کشاورزی و زیستمحیطی در ارتباط است. از این رو توصیف و کمّیسازی ساختمان خاک از اهمیت ویژهای برخوردار است. ولی ساختمان خاک بصورت کیفی (مکعبی، دانهای و ...) بیان میشود. هدف از این تحقیق تعیین پایداری خاکدانهها و استفاده از هندسۀ فرکتالی و تعیین بُعد فرکتالی ساختمان خاک در برخیازراستههایخاکبود که نتیجه در مدلهای کاربردی برای بیان فرآیندهای خاک و مدلسازی قابل استفاده خواهد بود. بنابراین از افقهای مشخصۀ هفت راستۀ خاک شامل انتیسول، ورتیسول، اریدیسول، مالیسول، الفیسول، هیستوسول و اینسپتیسول در استان فارس نمونهبرداری خاک (27 نمونه) انجام گردید. ویژگیهای خاک شامل توزیع اندازة خاکدانهها، بافت، درصد رطوبت اشباع، کربن آلی، EC، pH، گچ و آهک اندازهگیری و میانگین وزنی قطر خاکدانهها (MWD) و میانگین هندسی قطر خاکدانهها (GMD) و بُعد فرکتالی خاکدانهها محاسبه شد. نتایج نشان داد که همبستگی معنیداری بین بُعد فرکتالی مدلهای ریو و اسپوزیتو (DnR) و تیلر و ویتکرافت (DmT) با MWD و GMD با ویژگیهای خاک وجود داشت. این همبستگی بین پارامترهای فرکتالی با ماده آلی، جرم مخصوص ظاهری، درصد رس و درصد شن، قویتر از دیگر ویژگیهای خاک بود. همبستگی منفی و معنیداری (در سطح یک درصد) بین DnR و DmT با MWD و GMD وجود داشت. بهطوری که راستههای خاکی که عدد بُعد فرکتالی کمتری داشتند، MWD و GMD بزرگتری داشتند. ضریب تبیین، میانگین خطاها، ریشة میانگین مربعات خطاها، مجذور مربعات باقیماندهها، مجذور مربعات عدم برازش و آماره آکایک مطلوبیت بیشتر مدل تیلر و ویتکرافت را نشان داد. مدل ریو و اسپوزیتو نیز مدل مناسبی بود گرچه در مواردی بُعد فرکتالی را زیاد محاسبه کرد که دلیل آن احتمالاً حساسیت زیاد این مدل میباشد. بهطور کلی بُعد فرکتالی از اهمیت ویژهای برای مطالعه و کمّیسازی ساختمان خاک برخوردار است و مقدار آن به استثناء راستۀ هیستوسول در دیگر راستهها در محدودۀ مناسب (3) بود.https://jsw.um.ac.ir/article_38583_eabc1d8c1666f2955f3c5cf4843fec6f.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Interactive Effect of Fe and Pb on Decreasing Corn Pb Availability in a Pb-Polluted Soilاثر برهمکنش آهن و سرب بر کاهش قابلیت دسترسی سرب توسط گیاه ذرت در یک خاک آلوده به سرب118711993858410.22067/jsw.v31i4.59049FAنرگس تبرته فراهانیواحد اراک، دانشگاه آزاد اسلامی، اراک، ایرانامیر حسین بقائیدانشگاه آزاد اسلامی واحد اراکJournal Article20160923Introduction: Lead (Pb) is of great concern in environment because of its toxicity to animals and humans. Lead is a cumulative toxin and known carcinogen. Although, plants do not require Pb for growth, the bioaccumulation index of Pb in plants exceeds that of most other trace elements. It is therefore important to control Pb concentration in plants, especially in the edible parts of crops to ensure food safety. There are many factors that control Pb accumulation and availability to plants in agricultural soils such as Pb source, Pb loading rate, soil pH, soil cation change capacity (CEC), chloride concentration in soil solution and soil organic matter content. These are important factors that should be considered for evaluating Pb phyto-availability. In addition, element interactions can also affect the elements uptake. Thus, this study was performed to investigate the effect of converter sludge-enriched cow manure on the changes in corn Pb uptake in a Pb-polluted soil under greenhouse condition.
Materials and Methods: This pot experiment was conducted under greenhouse condition around the city of Arak, using a Fine loamy, mixed and thermic, Typic Haplargids soil. A factorial experiment with a randomized complete block design with 24 treatments in three replications was carried out. The treatments consisted of applying enriched cow manure (0, 15 and 30 t ha-1) with 0% and 5% pure Fe from converter. To investigate the effect of converter sludge-enriched cow manure on the changes in corn Pb uptake, a non-saline soil with low carbon percentage was selected. The soil was polluted with Pb from Pb(NO3)2 source at the concentrations of 0, 200, 300 and 400 mg Pb kg-1 soil and incubated for one month. Cow manure was produced in a local farm and aged for two years before the experiment. The cow manure was enriched with converter sludge and incubated for three months in room temperature. Then, the enriched cow manure was added to the Pb polluted soil and corn (Zea mays L. single grass 704) seeds were sown. After 60 days from the experiment, soil physio-chemical properties and soil and plant Pb concentration were measured.
Results and Discussion: The greatest and least DTPA-extractable-Pb were determined in the polluted soil (400 mg Pb) without applying cow manure and the polluted soil (200 mg Pb) treated with 30 t ha-1 enriched cow manure, respectively. The DTPA-extractable-Pb in uncontaminated soils was not detectable by atomic absorption spectroscopy (AAS). Increasing the amount of cow manure caused a significant reduction in DTPA-extractable-Pb as applying 15 and 30 t ha-1 cow manure in a polluted soil (300 mg Pb) resulted in a significant decrease in DTPA-extractable-Pb by 11.9 and 23.4 units, respectively. This can be accounted for by the role of organic and inorganic fractions of cow manure in decreasing soil Pb availability. Interactions between Fe and Pb appear to influence the soil Pb availability as application of 15 and 30 t ha-1 converter sludge-enriched cow manure in 300 mg Pb-polluted soil caused a significant decline in soil Pb availability by 10.4 and 9.3 units, respectively. The highest and least root Pb concentration were observed in the polluted soil (400 mg Pb) without applying cow manure and the polluted soil (200 mg Pb) treated with 30 t ha-1 enriched cow manure, respectively. The corn root Pb concentration in unpolluted soils was not detectable by AAS. Applying 5% (W/W) pure Fe from converter sludge in the polluted soil (300 and 400 mg Pb) which were not manured significantly decreased the root Pb concentration by 19 and 9 units, respectively which is explainable by the interaction existing between Pb and Fe in soil. Furthermore, root Pb concentration was affected by converter sludge enriched-cow manure as applying 15 and 30 t ha-1 converter sludge cow manure in a polluted soil (400 mg Pb) significantly decreased the root Pb concentration by 20.8 and 10.9 units, respectively. However, the role of cow manure in increasing pH and decreasing root Pb concentration cannot be ignored. The greatest and least shoot Pb concentration was obtained for the polluted soil (400 mg Pb) without applying cow manure and the polluted soil (200 mg Pb) treated with 30 t ha-1 enriched cow manure, respectively. The corn shoot Pb concentration in unpolluted soils was not detectable by atomic absorption spectroscopy (AAS). Interaction effects were also observed for shoot Pb concentration as using 5% (W/W) pure Fe from converter sludge in the polluted soil (300 and 400 mg Pb) which were not treated by cow manure significantly decreased the shoot Pb concentration by 4.1 and 4.7 units, respectively.
Conclusion: The results of this study showed that interactions between Pb and Fe seem to play an important role in reducing root and shoot Pb concentration. On the other hand, applying cow manure can increase the soil sorption properties such as CEC and decrease the soil Pb availability and plant Pb uptake which is explainable by the fact that the organic and inorganic fractions of manure impact the Pb availability. However, the influences of soil physico-chemical properties such as pH upon soil Pb availability should be taken into account.هدف این تحقیق بررسی اثر کود گاوی غنیشده با لجن کنورتور بر مقدار جذب سرب توسط گیاه ذرت در یک خاک آلوده به سرب بود. تیمارهای آزمایشی شامل کاربرد مقادیر 0، 15 و 30 تن در هکتار کود گاوی غنی شده با لجن کنورتور (به میزان 0 و 5 درصد وزنی آهن خالص) و همچنین خاک تیمار شده با مقادیر 0، 200، 300 و400 میلیگرم سرب در کیلوگرم خاک از منبع نیترات سرب میباشد. سپس کود گاوی غنی شده به خاک آلوده به سرب اضافه و بذر ذرت (سینگل کراس 704) کاشته شد. بعد از گذشت 60 روز از شروع آزمایش، ویژگیهای فیزیکی، شیمیایی خاک و غلظت سرب در خاک و گیاه ذرت اندازهگیری شد. کاربرد کود گاوی غنی شده با لجن کنورتور تاثیر معنیداری بر کاهش غلظت سرب ریشه و شاخساره گیاه داشت، به صورتی که کاربرد 30 تن در هکتار کود گاوی غنی شده در خاک آلوده به 300 میلیگرم سرب به ترتیب باعث کاهش 2 و 5/1 برابری در غلظت سرب ریشه و شاخساره گیاه شد. نتایج کلی این تحقیق حاکی از آن است که کاربرد کود گاوی غنی شده با 5 درصد آهن خالص از ترکیب لجن کنورتور احتمالاً توانسته است باعث کاهش قابلیت دسترسی سرب در خاک و گیاه شود که در اینجا میتوان به نقش بخش معدنی و آلی کود گاوی در کاهش قابلیت دسترسی به سرب اشاره کرد، هر چند که نقش اثر برهمکنش سرب و آهن در کاهش جذب سرب به وسیله گیاه نبایستی نادیده گرفته شود.https://jsw.um.ac.ir/article_38584_f0aa800477b0398c6bab02c8f966bca8.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Critical Level of Iron for Bean (Phaseolus vulgaris L.) Cultivation in Markazi Provinceتعیین حد بحرانی آهن برای لوبیا در استان مرکزی114811583858110.22067/jsw.v31i4.57439FAمحمدعلی خودشناسبخش تحقیقات خاک و آب، مرکز تحقیقـات و آمـوزش کشاورزی و منابع طبیعی اسـتان مرکـزی، سـازمان تحقیقـات، آمـوزش و تـرویج کشاورزی، اراک، ایران0000-0000-0000-0000جواد قدبیک لوبخش تحقیقات خاک و آب، مرکز تحقیقـات و آمـوزش کشاورزی و منابع طبیعی اسـتان مرکـزی، سـازمان تحقیقـات، آمـوزش و تـرویج کشاورزی، اراک، ایران0000-0000-0000-0000مسعود دادیوربخش تحقیقات خاک و آب، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان خراسان رضوی، سازمان تحقیقات، آموزش و ترویج کشاورزی، مشهد، ایرانJournal Article20160711Introduction: Soil test has an important role in plant nutrition management to obtain the economical agriculture system. The nutrient concentration in soils that indicates the division between responsive and non-responsive conditions is termed the critical level. Before any fertilizer recommendation, we should be aware of the amount of nutrient critical levels in each region. Soil test results in an area, is not applicable for other agricultural areas. Therefore, these tests should be carried out in the soils of a desired area, so that the soil test could be the base for fertilizer recommendation. Iron is an essential micro element in the soil that mainly was found as insoluble (Ferric or Fe3+) form. Solubility of total inorganic iron decreases between pH 7.4 to 8.5. Bean (Phaseolus vulgaris L.) crop is one of the most widely grown throughout the Markazi province in Iran and has high nutritional value for human. Knowing that bean is a sensitive plant to iron, and because of lack of any information about iron critical level and regional calibration, this study was conducted in Markazi province.
Materials and Methods: Eighteen soil surface samples (0-30 cm) selected with a wide range of soil properties and iron concentration (extracted with DTPA method) from different zone of province and prepared for greenhouse cultivation. Soil physical and chemical properties such as: (texture, pH, calcium carbonate, organic matter, cation exchange capacity, and electrical conductivity) of soil were determined by routine laboratory methods. In this study, bean plant responses were investigated by application of two levels of iron (0 and 10 mg kg-1) in soil as iron sulfate in the greenhouse experiment. All of soil samples received nitrogen, potassium, phosphorus, manganese, copper and zinc as; (150, 100, 25, 5, 5, 5) mg kg-1 as solution in each pot respectively. The greenhouse study was conducted in a factorial experiment with three replications as complete randomized design. Six bean seeds were planted in pots. After the second week three plants of these six seeds were kept.
Soil moisture was maintained at field capacity. At the end of vegetative phase, the shoot bean and iron concentrations were determined in plant samples. At the end of the vegetation period, the shoot parts of plants cut, and plant responses including; (dry matter weight, Fe concentration, total Fe uptake and relative yield) (DMcontrol./DMFe fertilizer*100) were determined.
Results and Discussion: The results showed that available iron content in the soil varied from 1.5 to 20 mg kg-1 of soil with a mean value of 7.75 mg kg-1. The bean plant responded to Fe application and their relationships with physical and chemical properties of soils, which were investigated were effected too. Analysis of variance showed that the effects of soil and Fe fertilizer application were separately significant at 1% level for (weight dry matter, Fe concentration and Fe uptake). The effects of the (soil and fertilizer) interaction were significant at 1% level for the Fe concentration and Fe uptake. The mean comparison test of plant responses was significant as affected by Fe fertilizer consumption. By using Cate-Nelson graphic method, the critical level of iron in soils was five mg kg-1. Amounts of percent relative frequency indicated that eight percent of the soils were less than five mg kg-1 Fe, 63% of soils between 5 to 10 mg kg-1, 16% of soil between 10 to 15 mg kg-1 and 13% of soil above 15 mg kg-1 Fe. Plant Fe concentration in the control treatment (without Fe application) was 439.4 (mg kg-1), but at the Fe treatment (10mg kg-1) increased to (534.4mg kg-1).
The Fe uptake significantly increased from 1.54 to 2.16 mg Fe pot-1 with the application of 10 mg-Fe kg-1. The Fe uptake differences between treatments was due to increase of dry matter weight, and the plant Fe concentration, and this was due to the fertilizer application. Relative yield and dry matter weight showed positive and significant correlation with (clay, CEC and Fe available), but sand revealed negative correlation with the plant's response. The Fe uptake showed positive and significant correlation with Fe available but negative and significant correlation with the sand. The regression equation showed that Fe uptake to be related with CEC significantly.
Conclusion: By using Cate-Nelson graphic method, the critical level of iron in soils was five mg kg-1. The plant parameters were predictable significantly by soil properties such as (clay, sand, silt, soil organic carbon and Fe concentration).کشت لوبیا در استان مرکزی از اهمیت زیادی برخوردار است. آهن از عناصر ضروری کممصرف جهت رشد لوبیا می باشد. مبنای توصیه کود آزمون خاک هست. برای اینکه آزمون خاک بتواند مبنای توصیه کودی قرار گیرد بایستی در شرایط خاکهای منطقه مورد مطالعه واسنجی گردد. در این راستا، شناسایی دقیق وضعیت خاکهای لوبیاکاری استان مرکزی، مطالعه تعیین حدود بحرانی آهن انجام شد. تعداد ۱۸ نمونه خاک با دامنه وسیعی از غلظت آهن قابلاستفاده انتخاب گردید. جهت بررسی تأثیر آهن بر گیاه لوبیا از دو سطح صفر و ده میلیگرم آهن از منبع سولفات آهن استفاده شد. آزمایش بهصورت فاکتوریل در سه تکرار در قالب طرح کاملاً تصادفی به اجرا درآمد. پس از اتمام مرحله رویشی، قسمت هوایی لوبیا برداشت و پارامترهای گیاهی شامل وزن ماده خشک لوبیا در هر گلدان، غلظت و جذب کل آهن در هر گلدان و عملکرد نسبی در هر خاک اندازهگیری شد. همچنین پاسخ لوبیا نسبت به مصرف آهن و ارتباط آنها با ویژگیهای فیزیکی و شیمیایی خاکها مورد تجزیه و تحلیل قرار گرفت. نتایج مقایسه میانگین نشان داد که تأثیر مصرف آهن بر پاسخهای گیاهی معنیدار بود. با استفاده از روش تصویری کیت – نلسون حد بحرانی آهن در خاکهای مورد مطالعه ۵ میلیگرم بر کیلوگرم خاک به دست آمد. پارامترهای گیاهی با استفاده از ویژگیهای خاک نظیر رس، شن، سیلت، کربن آلی و غلظت آهن قابلاستفاده خاک بهطور معنیداری قابل تخمین است.https://jsw.um.ac.ir/article_38581_cbd7e84c0a5253a4b5000bc9dd1ad77a.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Effect of Potassium Releasing Pseudomonads on Growth and K Uptake of Tomato in Two Soils with Different Amount of Available Kاثر تلقیح سودوموناسهای آزادکننده پتاسیم بر رشد و جذب پتاسیم گوجهفرنگی در دو خاک با مقادیر مختلف پتاسیم در دسترس115911703858210.22067/jsw.v31i4.58456FAمعصومه دیلمیرادتبریزمحمدرضا ساریخانیتبریزشاهین اوستانتبریز0000-0002-4291-341XJournal Article20160828Introduction: Potassium is a major and essential plant macronutrient and the most abundant absorbed cation in higher plants. Potassium (K) plays an important role in the growth, metabolism, and development of plants. There are three forms of potassium found in the soil viz., soil minerals, nonexchangeable and available form. Soil minerals make up more than 90 to 98 percent of soil potassium. It is tightly bound and most of it is unavailable for plant uptake. Plants can uptake potassium only from the soil solution. Many indigenous soil microorganisms have the potential to absorb and mobilize the fixed form of nutrients from trace mineral sources. The use of plant growth promoting rhizobacteria including potassium-solubilizing bacteria as a biofertilizer could work as a sustainable solution to improve plant nutrient uptake and production. In this study the effect of five isolates of Pseudomonas were assessed on the growth and K uptake of tomato in two different soils with less than 200 mg/kg and more than 400 mg/kg available potassium.
Materials and Methods In this study, two different soil, Khalat pushan (K 400 mg/kg) were used. All the isolates including S6-6, S10-3, S14-3, S19-1 and S21-1 used in this study belonged to Pseudomonas genus and their potential were examined as a potassium releasing bacteria (KRB). Bacterial isolates were cultured in NB medium and were used in pot experiments. Experiment was conducted in a completely randomized design with three replications in two different soils by application of five bacterial isolates and the control without inoculum. Tomato seeds were inoculated with bacterial isolates in non-sterile soil and in the presence of indigenous soil microflora and the experiment continued until the beginning of the reproductive phase. The rate of inoculation was 10 ml of bacteria per pot. Growth and nutritional parameters such as dry weight of shoot and root, chlorophyll index, content of K and P in plant tissue were measured. Data analysis was performed by SPSS software, and the means were compared at α꞊5% by Duncan test.
Results and Discussion: The results of statistical analysis in the soil with less than 200 mg/kg available potassium (Khalatpoushan) showed the significant effect of bacterial inoculation on chlorophyll index, shoot and root dry weight and potassium and phosphorus content in shoot and root in bacterial treatments compared to the control. The highest amount of chlorophyll index, shoot dry weight and shoot absorption of potassium and phosphorus was accounted for S21-1. The highest amount of root dry weight and root absorption of potassium and phosphorus was accounted for S14-3.The results of second experiment in soil with more than 400 mg/kg available potassium (soil collected from Kandovan) showed that the measured properties were not affected by bacterial treatments. The highest amount of chlorophyll index was achieved by S14-3. The highest uptake of shoot potassium and phosphorus were recorded in plants which were inoculated by S14-3 and S21-1; however, the differences were not significant. While in this study we did not measure released K by bacteria in in-vitro condition but in the previous studies, their ability in K releasing from mica minerals such as muscovite and biotite had been measured and reported. Production of organic acid is one mechanism which proposed to explain potassium releasing ability of potassium releasing bacteria. It seems that this mechanism has the role in P solubilization, K releasing and solubilizing other nutients by plant growth promoting rhizobacteria (PGPR).
Conclusions: These results suggested that plant growth stimulating efficiency of bacterial inoculants affected by soil nutritional condition. The bacterial inoculation had a much better stimulatory effect on plant growth in soils with low available potassium. In this experiment, two isolates, S21-1 and S14-3 were better than the other isolates. Study in this area should be done especially in isolation and identification of potassium releasing bacteria from different soil samples. In the next step, these isolates should be tested in different soils under different climate conditions of the country, to choose robust and efficient isolate and intorduce them as KSB biofertilizer in counntry. It was the first report in Iran to test Pseudomonas isolates as KSB, while in the previous studies other genera especially bacteria belonged to Bacillus was reported in Iran.پتاسیم یکی از عناصر غذایی اصلی ضروری برای گیاهان است که نقش حیاتی در فرایندهای گیاه دارد. این عنصر غالبترین کاتیون جذبی به وسیله گیاهان میباشد و در رشد و توسعه و متابولیسم گیاه نقش اساسی دارد. پتاسیم در خاک به اشکال قابل استفاده، غیرتبادلی و در ساختار کانیها وجود دارد. پتاسیمی که در ساختار کانیها حضور دارد بیش از 90 تا 95 درصد پتاسیم خاک را به خود اختصاص میدهد. این شکل پتاسیم (پتاسیم موجود در کانیها) برای گیاهان به این سادگی قابل استفاده نمیباشد، بلکه گیاهان قادرند پتاسیم را تنها از فاز محلول خاک جذب و مورد استفاده قرار دهند. برخی از ریزجانداران خاک قادرند با سازوکارهایی، پتاسیم تثبیت شده و غیرتبادلی خاک را به فرم قابل استفاده تبدیل کنند و فراهمی پتاسیم را برای گیاه افزایش دهند. استفاده از باکتریهای محرک رشد به ویژه باکتریهای آزادکننده پتاسیم به عنوان کود زیستی یک شیوه امیدبخش در بهبود تغذیه پتاسیمی گیاهان و تولید آنها بوده و شیوه همسو با کشاورزی پایدار میباشد. بر این اساس آزمایش بر روی جداسازی و شناسایی این قبیل از باکتریها و بررسی کارایی آنها در تحقیقات اخیر مورد توجه قرار گرفته است. در این پژوهش توانایی پنج جدایه میکروبی Pseudomonas spp. از باکتریهای آزادکننده پتاسیم شاملS6-6 ، S10-3، S14-3، S19-1 و S21-1 بر بهبود رشد و افزایش جذب پتاسیم توسط گیاه گوجهفرنگی در دو خاک با پتاسیم قابل استفاده کمتر از mg/kg 200 و خاک با پتاسیم قابل استفاده بیشتر از mg/kg 400 در حضور ریزجانداران بومی خاک بررسی شد. در این تحقیق دو خاک مختلف با میزان پتاسیم قابل استفاده کمتر از 200 میلیگرم بر کیلوگرم (خاک خلعتپوشان) و بیش از 400 میلیگرم بر کیلوگرم (خاک کندوان) مورد استفاده قرار گرفت. همه جدایههای باکتریایی مورد استفاده در این پژوهش (S6-6، S10-3، S14-3، S19-1 و S21-1) متعلق به جنس سودوموناس بودند و توانایی آنها به عنوان باکتریهای آزادکننده پتاسیم مورد ارزیابی قرار گرفت. جهت استفاده باکتریها به عنوان زادمایه باکتریایی، ابتدا کشت تازهای از آنها در محیط نوترینت براث تهیه شد و برای تلقیح کشت گیاه مورد استفاده قرار گرفت. برای تلقیح هر گلدان از 10 میلیلیتر زادمایه باکتریایی استفاده شد. آزمایش در قالب طرح کاملاً تصادفی در دو خاک با مشخصات فوق با حضور 5 جدایه باکتری و یک تیمار شاهد (بدون تلقیح میکروبی) با در نظر گرفتن سه تکرار به انجام رسید. بذرهای گوجهفرنگی با زادمایه باکتریایی آغشته شد و کشت در خاک غیراستریل در حضور ریزجانداران بومی خاک انجام پذیرفت. آزمایش تا ابتدای فاز زایشی پیش رفت و پارامترهای رشدی و تغذیهای گیاه (نظیر شاخص کلروفیل، وزن تر و خشک بخش هوایی و ریشه، مقادیر عناصر فسفر و پتاسیم) اندازهگیری شد. آنالیز دادهها با نرمافزار SPSS صورت پذیرفت و مقایسات میانگین به روش دانکن انجام شد. نتایج در خاک با پتاسیم قابل استفاده کمتر از mg/kg 200 نشان داد که شاخص کلروفیل، وزن خشک اندام هوایی و ریشه،جذب پتاسیم و فسفر در اندام هوایی و ریشه متأثر از جدایههای باکتریایی بوده است. مقایسه میانگین نشان داد جدایه S21-1 بیشترین شاخص کلروفیل، وزن خشک اندام هوایی، جذب پتاسیم و فسفر اندام هوایی را داشت که به ترتیب باعث افزایش 7/23، 12، 20/22 و 41 درصد نسبت به شاهد شد. جدایه S14-3 بیشترین وزن خشک ریشه، جذب پتاسیم و فسفر ریشه را داشت و به ترتیب باعث افزایش 6/36، 88/24 و 7/32 درصد نسبت به شاهد شد. اثرات باکتری بر ویژگیهای اندازهگیری شده در خاک با پتاسیم قابل استفاده بیشتر از mg/kg 400 معنیدار نشد. اما مقایسه میانگین نشان داد بیشترین مقدار شاخص کلروفیل متعلق به جدایه S21-1 بود که نسبت به شاهد 11/14 درصد افزایش نشان داد و دو جدایه S14-3 و S21-1 بیشترین جذب پتاسیم و فسفر اندام هوایی را داشتند که به طور متوسط نسبت به شاهد 7 درصد افزایش نشان دادند، هر چند این اختلافات معنیدار نبود. در این آزمایشات، جدایههای S21-1 و S14-3 نسبت به سایر جدایهها برتر شناخته شدند. این آزمایش مشخص ساخت که اثربخشی باکتریهای آزادکننده پتاسیم متاثر از پتاسیم قابل استفاده خاک میباشد و هر چه میزان پتاسیم قابل استفاده در خاک کمتر باشد میتوان انتظار داشت که اثربخشی این باکتریها افزایش یابد. تحقیقات در زمینه جداسازی باکتریهای آزادکننده پتاسیم بایستی ادامه داشته باشد و بایستی جدایههای باکتری در شرایط مختلف محیطی و در خاکهای متفاوت مورد آزمایش قرار گیرند، تا با آزمایشاتی از این دست بتوان سویههای کارآمد را برای استفاده در عرضه کشاورزی معرفی نمود.https://jsw.um.ac.ir/article_38582_58177b59c5d5ded56c227f19d08c26b8.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Potassium Solubilizing Bacteria Ability to Increase Wheat Growth and Potassium uptake under in vitro Conditionتوانایی باکتریهایحلکننده پتاسیم در افزایش رشد گندم و جذب پتاسیم در زیستگاه درون شیشهای12011343857910.22067/jsw.v31i4.57235FAنعیمه عنایتی ضمیرگروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شهید چمران اهوازاحمد لندیگروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه شهید چمران اهواز0000-0002-2807-5894Journal Article20160702Introduction: Potassium (K) is the third major essential macronutrient for plant growth. Without adequate potassium, the plants will have poorly developed roots, grow slowly, produce small seeds and have lower yields. Due to imbalanced fertilizer application, potassium deficiency is becoming one of the major constraints in crop production. The concentrations of soluble potassium in the soil are usually very low and more than 90% of potassium in the soil exists in the form of insoluble rocks and silicate minerals. Soil microbes have been reported to play a key role in the natural K cycle and therefore, potassium solubilizing microorganisms present in the soil could provide an alternative technology to make potassium available for uptake by plants. Thus, identification of microbial strains capable of solubilizing potassium minerals quickly can conserve our existing resources and avoid environmental pollution hazards caused by heavy application of chemical fertilizers.
Materials and Methods: This study aimed to isolate and identified potassium solubilizing bacteria and evaluate those effect on K availability from muscovite and vermiculite sources to wheat crop under in vitro condition. The study was conducted as factorial in completely randomized design at three replications included bacterium inoculation (control, isolate1, isolate 2) and four k sources (muscovite, vermiculite, muscovite+ K2HPO4, vermiculite+ K2HPO4). Bacterial isolates were obtained from wheat rhizosphere on modified Aleksandrov medium containing muscovite and vermiculite powder as potassium source. Nutrient broth medium was used to prepare an overnight culture of bacteria to inoculate in Aleksandrov medium, which was used to study the dissolution of silicate minerals. The zone of solubilization recorded on Aleksandrov medium. Then the ability of two bacterial strains, including Bacillus subtilis and Corynebacterium glutamicum to release mineral K from muscovite and vermiculite was investigated. After 18 days of seed culture, aerial part of plant growth was dry digested and K concentration was determined by flame photometry. Dry and fresh weight of aerial part and root, plant height and root length was recorded.
Results: Three K-solubilizing isolates from 15 isolates identified by biochemical and molecular methods which belonged to Bacillus subtilis, Pseudomonas putida and Corynebacterium glutamicum. The potassium solubilization zone of each strain on Aleksandrov medium containing muscovite were 8.1, 65.1 and 6.3, respectively. The zone was also 9, 8 and 5.8 in Aleksandrov medium in the presence of vermiculite as insoluble potassium source. According to these results potassium release from vermiculite was more than muscovite, in spite of more potassium content of muscovite. According to the obtained results two strains Bacillus subtilis and Corynebacterium glutamicum were selected for in vitro experiment because of halo to colony diameter ratio. The ratio of halo to colony diameter in the presence of muscovite for Bacillus subtilis, Pseudomonas putida and Corynebacterium glutamicum was 1.5, 0.72 and1.3, respectively. These ratios were 2, 1.4 and 0.8, respectively in the medium containing vermiculite as insoluble potassium source. The results showed that the effect of bacteria inoculation was significant (pهوادیدگی کانیهای خاک، خاستگاه بسیاری از عناصر غذایی ضروری رشد گیاه مانند پتاسیم هستند. کانی های میکایی خاستگاه اصلی برآورد پتاسیم در خاک های کشورمان هستند. این پژوهش با هدف جداسازی باکتریهای حل کننده پتاسیم از ریزوسفر گندم و بررسی توانایی این باکتریها در بهره گیری از پتاسیم ساختاری کانیهای مسکوویت و ورمیکولیت انجام شد. این پژوهش در زیستگاه درون شیشهای با آرایش فاکتوریل در قالب طرح کاملاً تصادفی در 3 تکرار انجام شد. فاکتورهای آزمایش سه سطح باکتری (شاهد بدون مایه زنی، و مایه زنی با باکتری1 و 2) و چهار گونه تیمار کانی پتاسیم (مسکویت، ورمیکولیت، مسکویت+K2HPO4 ، ورمیکولیت + K2HPO4) بود. در پایان دوره کشت، بخش هوایی گیاه برداشت و به روش خاکستر خشک پتاسیم آن به کمک فروغ سنج اندازه گیری شد. همچنین صفات وزن تر و خشک اندام هوایی و ریشه، بلندی گیاه و درازی ریشه اندازه-گیری شد. این بررسی نشان داد که پیامد مایه زنی دو باکتری برهمه ویژگیهای اندازهگیری شده در سطح یک درصد معنیدار است. همه ویژگی های یاد شده در بودن Bacillus subtilis و کانی ورمیکولیت بالاترین اندازهها را داشتند. اندازه پتاسیم جذب شده در گیاه به گونه معنیداری وابسته به بستر کشت گیاه بود. اندازه پتاسیم جذب شده در گیاه، در سطح یک درصد به گونه معنیداری وابسته به باکتری حلکننده پتاسیم بود. بیشترین غلظت پتاسیم اندام هوایی (062/0 درصد) در تیمار بستر ورمیکولیت به همراه پتاسیم محلول در بودن Bacillus subtilis بود. بیشترین اندازه جذب پتاسیم در اندام هوایی گیاه ( 049/0میلیگرم در گلدان) نیز در بستر ورمیکولیت به همراه پتاسیم محلول در بودن Bacillus subtilis و پس از آن در اندام هوایی گیاه (036/0 میلیگرم در گلدان) کشت شده در بستر مسکویت به همراه پتاسیم محلول در بودن Bacillus subtilis با اختلاف معنیدار در سطح 5 درصد اندازهگیری شد.https://jsw.um.ac.ir/article_38579_12ee8fad439a509839922a2cf361bd3c.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Characterizing the Error Structure of Selected Soil Particle Size Distribution Modelsارزیابی ساختار خطا دربرخی مدلهای توزیع اندازه ذرات خاک113511473858010.22067/jsw.v31i3.57181FAفاطمه افراسیابیدانشگاه ارومیهحبیب خداوردیلودانشگاه ارومیهفرخ اسدزادهدانشگاه ارومیهJournal Article20160630Introduction Particle size distribution (PSD) is one of the most fundamental features of soil physics that is widely used as the most common input for predicting several key soil attributes. The mathematically representing the PSD provides several benefits to soil mechanics, physics, and hydrodynamics as well as helps to convert PSD data of various particle size classification systems to the desired one. Consequently, the correct and consistent descriptions of soil PSD by using mathematical functions is necessary.
The PSD models have often been evaluated in terms of their general performance for predicting the entire PSD curve. However, a given model may be feasible and globally perform well to generate the whole PSD curve but locally may fail to predict some specific points on the curve. To our knowledge, as well as, PSD models have not been widely tested for salt-affected soils with different levels of salinity/sodicity.
The aim of this study was to determine the error structure of several more accurate PSD models in selected soil samples with different levels of salinity and sodicity.
Materials and Methods Twenty four locations neighboring the western edge of threatened hypersaline Lake Urmia were sampled in this study. The locations were selected considering the available soil maps so that soils with wide range of salinity/sodicity were sampled. Selected physical and chemical properties of the soil samples were determined by standard methods. The performance of six PSD models including Modified Logistic Growth (MLG), Fredlund type models with three (Fred-4p) and four (Fred-3p) parameters, Anderson (AD), ONL, and Weibull (Wei), which have been reported as the most accurate PSD models by previous studies, was evaluated by using different efficiency criteria that offer various performances depending on the range of particle sizes.
An iterative nonlinear optimization procedure was used to fit the observed cumulative PSD data of the soils to the PSD models. Since every statistical criterion evaluates a part and some (and not all) aspects of the correspondence between measured and predicted values, we suggest that an effective assessment of model performance should include a suitable combination of criteria. Furthermore, dependence of the models performance to the range of soil particle sizes was examined.
Results and Discussion The soils differed widely in their EC (range = 85dS/m and CV = 159%), ESP (range = 67 % and CV = 71 %), and PSD (CV of clay and silt particles, 48 and 55 %, respectively). Soil textural class of the soils was differed widely from sandy loam to clay. All the soils were calcareous and alkaline.
The results showed that according to the efficiency criteria, including R2 (coefficient of determination), RMSE (Root Mean Square Error) and Er (Relative Error), all of the models have high efficiency, so that, the lowest average value of R2 in models was 0.992 and the maximum value of RMSE and Er was 0.028 and 0.045, respectively.
Prediction error of the models was dependent on the diameter for which we predict the cumulative fraction and decreases with increasing of the soil particles diameter. The performance of the models showed a significant quadratic polynomial relationship with sand content of the samples, so that, the studied models had the lowest performance in soils containing 30 to 45 percent sand.
The point-to-point error structure of model represents a decrease in systematic error in estimating coarse soil particles, while the models over-estimated the relative frequency of the fine soil particles. In addition, the values of relative error were also lower for coarse particles of soil, so that, the Wei model (for example) had the lowest Er value for 100 to 500 μm diameter soil particles. The relatively high correlations between parameters of Fred-3p, MLG and ONL models show insights to reduce the number of their parameters.
Furthermore, parameters a and c of MLG model, parameters μ and α of ONL model and parameter α and m of Fred-3p model had a statistically significant correlations. The relatively high correlations between parameters of the PSD models show insights to reduce the number of their parameters which increases their applicability.
Conclusion The studied models generally performed well to predict the whole PSD curve, but their performance was particle size dependent. This implies that, one should consider the range of sizes of soil particles for which the model are used. A model might be accurate enough for predicting some ranges of particle diameter or the whole PSD, but not for particular range of particle sizes. Using such models might lead to large errors in predicting the specific PSD range of interest.توزیع اندازه ذرات (PSD) خاک یکی از اساسیترین مشخصههای فیزیکی خاک است که به طور گسترده در برآورد بسیاری از ویژگیهای کلیدی خاک کاربرد دارد. بنابراین توصیف صحیح و پیوسته منحنی PSD خاکها با استفاده از توابع ریاضی ضروری است. هدف از این مطالعه بررسی ساختار خطای تعدادی از مدلهای برتر PSD در 24 نمونه خاک با کلاس های بافتی لوم شنی تا رس سیلتی از اراضی حاشیه غربی دریاچه ارومیه با سطوح مختلف شوری (از 4/85-8/0 دسیزیمنس بر متر) متاثر از شوری و سدیم بود. برای این منظور 6 مدل برتر PSD شامل لوجستیک (MLG)، فردلاند چهار و سه پارامتری (Fred-4p و Fred-3p)، اندرسون (AD)، (ONL) Offset-Nonrenormalized Lognormal و ویبول (Wei) انتخاب شده و جنبههای گوناگون کارآیی آنها ارزیابی شد. نتایج نشان داد که براساس ضرایب کارآیی شامل) R2ضریب تبیین)، RMSE (ریشه میانگین مربعات خطا) و Er (خطای نسبی) همهی مدلهای مورد بررسی دارای کارآیی بالایی بوده و کمترین مقدار میانگین R2 در مدلها برابر با 992/0 و بیشترین مقدار RMSE و Er نیز به ترتیب برابر با 028/0 و 045/0 بود. با این حال، بین کارآیی مدلها با درصد شن نمونهها ارتباط معنیداری از نوع چندجملهای درجه دو مشاهده شد که براساس آن مدلهای مورد بررسی در خاکهای حاوی 30 تا 45 درصد شن کمترین کارآیی را داشتند. ساختار خطای نقطه به نقطه مدلها بیانگرکاهش خطای سیستماتیک در برآورد ذرات درشت خاک توسط مدلها بود در حالی که اغلب مدلها فراوانی ذرات ریز خاک را (کوچکتر از 100 میکرومتر) بیشتر از واقعیت برآورد کردند. افزون بر این، مقدار خطای نسبی نیز برای ذرات درشت خاک کمتر بود به گونهای که مدل ویبول (برای نمونه) برای ذرات با قطر 100 تا 500 میکرومتر حداقل درصد خطای نسبی را داشت. همبستگی نسبتا بالا بین پارامترهای مدل Fred-3p،MLG و ONL بیانگرامکان کاهش تعداد پارامترهای این مدلها است. باتوجه به نتایج بدست آمده، علیرغم کارآیی عمومی بالای مدلهای مورد بررسی در برآورد کل منحنی PSD، کارآیی هر مدل وابسته به اندازه ذرات بود. بنابراین، یک مدل ممکن است برای برآوردکل PSD خاک دقت کافی داشته باشد ولی برای برآورد گسترهای خاص از PSD خاک مناسب نباشد. استفاده از چنین مدلی میتواند خطایی چشمگیر در برآورد گستره اندازهای موردنظر ایجاد کند.https://jsw.um.ac.ir/article_38580_769cf953945a4e545fb1553e776c9c5d.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023The Effect of Integrated Crop Management on Soil Chemical Propertiesتأثیر مدیریت تلفیقی محصول بر کربن و اشکال نیتروژن خاک109311073857710.22067/jsw.v31i4.57204FAامیرصالح بغدادیگروه زراعت، واحد کرج، دانشگاه آزاد اسلامی، کرج، ایرانمهیار بالازادهگروه زراعت، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایرانعلی کاشانیگروه زراعت، واحد کرج، دانشگاه آزاد اسلامی، کرج، ایرانفرید گل زردیبخش تحقیقات ذرت و گیاهان علوفهای، مؤسسه تحقیقات اصلاح و تهیه نهال و بذر، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایرانJournal Article20160701Introduction In recent years, continuous operation and disrespect to crop rotation has caused the destruction of soil organic matter so that organic matter in arid and semiarid areas of the country is at least possible and According to the hazards and contamination of chemical fertilizers usage, need to reduce consumption of these inputs and find ecological methods to provide Nutritive requirements for crops, to maintain and increase soil fertility has felt. One of the these ways is using of the appropriate pre-sowing plants, by backing pre-sowing plants (green manure) in soil causes to increase the carbon and organic matter, total nitrogen and soil fertility that this phenomenon occurred as a result of microbiological processes and it causes to releasing the nutrients for the plants. Therefore, this study aimed to investigate of integrated crop management on characteristics of soil nutrients and nitrogen mineralization during the period after adding the green plants remains was conducted in Karaj.
Materials and Methods This research is performed during growing season 2013-14 at the Agricultural Research Station of Islamic Azad University of Karaj, Iran. The experiment was conducted as a split plot based on a randomized complete block design with four replications. Main factors include pre-sowing treatments in 4 levels (Perko PVH, Buko, Cattle manure and Fallow) and sub factors also included nitrogen levels (120 and 240 and 360 kg ha-1, utilized urea source). Perko PVH and Buko belong to Brassicaceae family that if they back to the soil they can increase the oraganic matter. Pre-sowing of Perko PVH and Buko were planted in middle of March. Pre-sowing plants before that they going to flowerer stem coincide with the end of the vegetative stage, two weeks before the corn planting they was picked from the soil surface and the remains mixed with soil by rotavator machine. In order to apply cattle manure application in intended plots the amount of 7 ton ha-1 was given to the soil before the corn planting. On 6 July 2014 corn planting was done by pneumatic machine. Nitrogen fertilizer in 3 times was separated and as a topdressing form in the amount of 10, 70 and 20 percentage in the five-leaf stage, Stem elongation and tasselling emergence stage Were applied. After harvesting corn silage, Samples randomly from zero to 30 and 30 to 60 cm depths in each plot were taken and mixed together. Soil samples separately were dehumidified by air and were passed from 2 mm sieve. Organic carbon of soil samples by oxidation in the presence of potassium dichromate and concentrated sulfuric acid (Hesse, 1971) and total nitrogen were determined by Kjel (Hesse, 1971 ) and for measuring of soil mineral nitrogen, of samples tested by the 2 mol KCl solution the extraction and ammonium nitrate samples were measured by means of distillation and titration with HCl .Data analyses are done by using SAS (Version 9.1.3) statistic software mean comparison was done using the LSD test at probability level of 5%.
Results and Discussion Analysis of variance illustrated that the effect of pre-sowing on organic carbon, total nitrogen, nitrate nitrogen and soil ammonium nitrogen in 5% probability level was significant, so that in all traits, Perko PVH and Buko were the best treatments than the fallow and animal manure treatments. The effect of nitrogen levels on all traits were significant in 1% probability level, so that by increasing the nitrogen usage, the rate of these traits increased. Interaction between pre-sowing treatments and nitrogen levels on soil organic carbon, total nitrogen, nitrate nitrogen and ammonium nitrogen in the soil were highly significant in 1% probability level; so that Perko PVH pre-sowing treatment and consumption of 360 kg ha-1 nitrogen of urea source, the highest values of these traits created. The highest percentage of soil organic carbon affected by Perko PVH pre-sowing treatment and rate of 360 kg ha-1 nitrogen in a rate of 1.08% and the lowest percentage of soil organic carbon was related to cattle manure treatment and rate of 120 kg ha-1 nitrogen in a rate of 0.58. The highest percentage of total soil nitrogen affected by Perko PVH pre-sowing treatment and rate of 360 kg ha-1 nitrogen in a rate of 0.102% and the lowest percentage of total soil nitrogen was related to cattle manure treatment and rate of 120 and 240 kg ha-1 nitrogen in rates of 0.052 and 0.047.
Conclusions By the results of this study, the effect of integrated crop management with integrated application of organic fertilizers with nitrogen fertilizer, the cause of the soil Chemical properties and soil fertility is increased. Hence the use of organic fertilizers, meanwhile the significant reduction in the use of nitrogen fertilizer can reduce their environmental impacts. The result of study indicated that pre-sowings of Perko PVH and Buko had a positive and significant effect on soil chemical parameters and soil chemical characteristics reaction on pre-sowing yield is different. In general can say that planting the pre-sowing plants and return the remains to soil causing the protection and increasing soil fertility and consequently causing the Increase the quantity and quality of the crop and can be considered as a one way to achieve sustainable agriculture.بهمنظور بررسی تأثیر مدیریت تلفیقی محصول بر میزان کربن آلی، نیتروژن کل، نیتروژن نیتراتی و نیتروژن آمونیومی خاک بعد از برداشت گیاه ذرت سیلویی در دو عمق خاک، آزمایشی مزرعهای بهصورت کرتهای خردشده بر پایه طرح بلوکهای کامل تصادفی در چهار تکرار در سال زراعی 93-1392 در کرج اجرا شد. فاکتور اصلی شامل تیمارهای پیشکاشت در چهار سطح آیش، کود دامی، کود سبز پرکو (Perko PVH) و بوکو (Buko) از خانواده براسیکاسه، فاکتور فرعی کود نیتروژن در سه سطح 120، 240 و 360 کیلوگرم در هکتار از منبع اوره در نظر گرفته شد. نتایج تجزیه واریانس و مقایسه میانگین دادهها نشان داد برهمکنش تیمارهای پیشکاشت و سطوح نیتروژن اثر معنیدار بر میزان کربن آلی، نیتروژن کل، نیتروژن نیتراتی و آمونیومی خاک و محتوای نیتروژن ذرت داشت. بیشترین میزان کربن آلی (08/1 و 97/0 درصد)، نیتروژن کل (102/0 و 087/0 درصد)، نیتروژن نیتراتی (9/26 و 81/21 میلیگرم در کیلوگرم) و نیتروژن آمونیومی (05/2 و 95/1 میلیگرم در کیلوگرم) خاک پس از برداشت ذرت سیلویی در تیمار پیشکاشت پرکو و بوکو به همراه 360 کیلوگرم نیتروژن در هکتار مشاهده شد و کمترین میزان کربن آلی (58/0 درصد) و نیتروژن کل (047/0 درصد) خاک در تیمار پیشکاشت کود دامی به همراه 120 کیلوگرم نیتروژن در هکتار مشاهده شد. بیشترین عملکرد علوفه و محتوای نیتروژن ذرت با کاربرد کود سبز پرکو و بوکو به دست آمد. با توجه به نتایج بهدستآمده از این پژوهش، گیاهان پرکو و بوکو بهعنوان بهترین پیشکاشت در منطقه کرج می-باشند و میتوانند تیمارهای امیدبخشی بهمنظور کاهش مصرف کود نیتروژن شیمیایی باشند.https://jsw.um.ac.ir/article_38577_daa5f05138e8c88e3d8a7331fa70f9e1.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Application of Fe-EDDHA on Soybean and Distribution of Chemical Forms of Iron in Soils of Fars Provinceاثرسکوسترین آهن بر رشد گیاه سویا و توزیع شکلهای شیمیایی آهن در خاکهای استان فارس110811193857810.22067/jsw.v31i4.56933FAلیلا تابندهمرکز تحقیقات کشاورزی فارسمحمدرضا بخشیگروه خاک و آب سازمان جهاد کشاورزی زنجان، ایرانJournal Article20160620Introduction
Among essential plant microelements, iron (Fe) exert the highest restriction of crop production in Fars Province. Trace elements in the soil is composed of forms into 5 groups. These are the water-soluble and variable, adsorbed, chelate creating with complex compounds, secondary clay minerals, forms insoluble metal oxide minerals, and primary minerals. Water-soluble, changeable, adsorbed or form in chelates to be present as balance in the soil is noted and to be important for plants in nutrition.
Materials and Methods
In a greenhouse experiment was done with Soybean planting, the effects of Fe chelate (FeEDDHA) fertilizer levels on William cultivar of soybean (Glycine max L.) growth and chemical composition were studied by using a completely randomized design with 3 replications. Treatments were consisted of 10 soil samples and 3 levels of Fe applications (control, 5 and 10 mg.kg-1 as Fe EDDHA). Beside some physical and chemical soil properties and Extractable iron content with DTPA and EDTA were determined. By sequential extraction methods of Singh & Sposito ( 1982), chemical forms of Iron, exchangeable iron (Exch-Fe), organic bounded iron (OM-Fe), amorph iron oxides bounded iron (AFeOX-Fe), crystal iron oxides bounded iron (CFeOX-Fe) contents of soils were determined. Then, Concentration and uptake of Fe, Mn, Cu and Zn in plant were calculated.
Results and Discussion
carbonate, organically, amorphous oxide, crystalline iron oxide bounded and residual forms of iron were 0.0053, 0.0016, 0.44, 21.1 and 78.6% of the total iron as average, respectively. Therefore, content of carbonate, organically bound iron of soil, represented only a small fraction would not be considered as important as the total iron. In other words, crystalline iron oxide bound iron and residue iron forms constitued an important part of total iron.
Considering the average iron content of the soil related to chemical forms of iron was arrenged such as:
Res-Fe>CFeOX-Fe>AFeOX-Fe>Car-Fe> OM-Fe > Exch.-Fe
Applications of Fe had significant effect on dry matter, concentration, and uptake of Fe, Zn, Cu and Mn, extractable forms via extracting DTPA, EDTA, organic and exchangeable forms in soybean compared to control. Among chemical forms of iron, organic form with the amount of available iron plant (extraction by DTPA) had significant positive correlation. Also, many of the physical and chemical properties of calcareous soils studied, were significantly correlated with some chemical forms and amount of iron uptake by plant. DTPA extractable iron had negative correlation with pH ( R2= 0.514*) and EDTA extractable iron had positive correlation with organic matter (R2= 0.428*).
Conclusions
Application of Fe EDDHA, was leaded to significant increase organic and plant available (DTPA) forms of iron and due to significant regression equation (r=0.435*) between two chemical forms of iron (organic and DTPA extracted), it can be inferred that, the bulk of available iron plant was in form of organically bound. One reason for the positive reaction to the use of Fe EDDHA, subjected to a significant increase absorbable forms of iron in the studied soils.
Keywords: Chemical and Physical properties of soil, DTPA, EDTA, Iron, Sequential extractionاز بین عناصر کم مصرف مورد نیاز گیاهان، آهن، محدودیتهای زیادی را برای محصولات کشاورزی استان فارس به خود اختصاص داده است.در یک آزمایش گلخانهای،اثر کود سکوسترینآهن 138 بر رشد و ترکیب شیمیایی رقم ویلیامز (Glycine max L.)سویا به صورت فاکتوریل و در قالب طرح کاملاً تصادفی و با سه تکرار، مورد مطالعه قرار گرفت. تیمارها،شامل 3سطح کودی از منبع سکوسترین آهن (شاهد، 5 و10میلیگرم برکیلوگرم خاک) و10 نمونه خاکمیباشند. کاربرد آهن، منجر به افزایش معنیدار وزن خشک، غلظت و جذب آهن و کاهش معنیدار غلظت و جذب روی، مس و منگنز در گیاه سویا گردید.سکوسترین آهن، اثر معنیداری بر شکلهای قابل استخراج باعصارهگیرهای دیتیپیا، ایدیتیا، شکلهای آلی و تبادلی آهن نشان داد. شکلآلی اهن، با مقدار آهن قابل استفاده گیاهی (عصارهگیری شده با دیتیپیا)، همبستگی مثبت معنیدار داشت. همچنین، بسیاری از ویژگیهای فیزیکی و شیمیایی خاکهای آهکی مورد مطالعه، با برخی از شکلهای شیمیایی و مقدار جذب آهن گیاهی، همبستگی معنیداری نشان دادند.https://jsw.um.ac.ir/article_38578_6ccc317fbb783820388523433d8212e4.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Effect of Polyacrylamide Polymer on Wind Erosion Control of Sandy Soil in Azadegan Plainبررسی اثر پلیآکریلآمید در کنترل فرسایش بادی خاک شنی دشت آزادگان107010823857510.22067/jsw.v31i4.32428FAفاطمه ارزاقیگروه علوم خاک، دانشکده کشاورزی، دانشگاه شهید چمران اهوازاحمد فرخیان فیروزیگروه علوم خاک، دانشکده کشاورزی، دانشگاه شهید چمران اهواز0000-0002-4955-1845نعیمه عنایتی ضمیردانشگاه شهید چمران اهوازبیژن خلیل مقدمدانشگاه کشاورزی و منابع طبیعی رامین خوزستانJournal Article20140218Introduction: Wind erosion is the most important agent of environmental degradation, poverty of soil, air pollution and the dust spread. Wind erosion is causing a lot of damage to crops, buildings, facilities and vehicles. The first step of the wind erosion control is the stabilization of soil particles. Soil stabilizing methods to control wind erosion can be classified into mechanical, biological and chemical stabilization. Mechanical soil stabilization type is relatively time-consuming and costly. Biological stabilization is a traditional way that exhibits a long-term validity but sandy soil cannot provide essential water and nutrition elements needed by plant. Recently, chemical stabilization such as high-molecular-weight anionic polyacrylamide (PAM) has attracted the attention of researchers because of its advantages in easy and quick construction, and the improvement of the growing conditions for plant. However PAM has been mainly used to control water erosion and there is still little available information regarding the effectiveness of PAM on preventing soil loss by wind erosion. The main objective of this study was to investigate the feasibility of using PAM in wind erosion controlling. Also, effects of PAM on some soil physical and chemical properties and their temporal variability were evaluated.
Materials and Methods: In this study polyacrylamide polymer was used as a restoration of soil and soil structure stabilizer on sandy soil of Azadegan Plain (Khuzestan province, Iran). Consequently, an experiment was conducted as factorial based on completely randomized design with three replicates. The experimental treatments were consist polyacrylamide polymer (PAM) at three levels (0, 0.5, and 1 %), soil moisture at two levels (80% FC and dry) and time duration at three levels (15, 30 and 45 days). The emulsion of PAM was sprayed homogeneously on the soil surface. After passing each time treatment, penetration resistance and some physical and chemical properties of soil was measured. Finally after doing all measurements, the treatment with maximum penetration resistance were selected and the sample was prepared for wind tunnel testing. The wind erosion experiments were conducted in a wind tunnel. Soil samples were located in removable trays. The width and length of the trays was 30 and 100 cm, respectively. The wind erosion experiments were performed under wind velocity of 12 m s−1 according to the actual situation of study area.
Results and Discussion: The results indicated that in comparison to control, soil acidity decreased at both levels of the polymer with increasing time. The decreasing of soil acidity in wet treatments was more than dry treatment. The lowest amount of pH was obtained in the 30-day wet treatment at 1% polymer level. The results show from the 30th day onwards, soil pH increased, which is probably due to the polymer degradation. With passing time, soil electrical conductivity (EC) at both levels of the polymer (0.5 and 1%) increased and decreased respectively after 30 days. These observations are probably because after 30 days the properties of polymer-hydrophilic units gradually decrease and water adsorption was reduced or that soil soluble salts were adsorbed by polymer particles. The results also showed with passing time, Mean Weight-Diameter of Soil Aggregates (MWD) increased and then after 30 days declined. The largest MWD was observed in 30 days treatment at 1% polymer level. After thirty days, its effect has probably diminished due to polymer degradation. Furthermore, the results showed no significant difference of bulk density among treated soil with different level of polymer, but application of polymer caused to decrease bulk density comparison to control. Polymer application increased soil penetration resistance significantly. Using 1% of polymer increased it to 6 kg/m2. The results also indicated that the soil resistance at first increased with time and then decreased significantly. The amount of soil penetration resistance at 45-day was less than 15-day. The results of wind tunnel with a maximum 12 m/s wind velocity showed that application of the polymer reduced the erosion of sands samples to zero.
Conclusion: The research results indicated that PAM application increased soil penetration resistance and MWD. The polymer could improve the structure of soil aggregates and increase the amount of dry-stable aggregates and therefore decrease soil bulk density. Spraying PAM solution on the surface of soil significantly decreased the wind erosion amounts. Therefore, this inexpensive and easily usable polymer can be considered as a soil stabilizer to control wind erosion in arid and semiarid areas.فرسایش بادی از عوامل اصلی تخریب محیط زیست، فقر خاک، آلودگی هوا و پراکندن گرد و غبار میباشد. فرسایش بادی باعث خسارات زیادی به محصولات کشاورزی، ساختمانها، تأسیسات و وسایل نقلیه میشود. در این تحقیق پلیآکریلآمید به عنوان یک ترمیم کننده خاک در دو سطح 5/0 و 1 درصد به ماسه بادی منطقه دشتآزادگان افزوده شد. برخی ویژگیهای فیزیکی خاک و مقاومت در برابر فروروی خاک در 3 فاصله زمانی 15، 30 و 45 روز پس از تیمار مورد بررسی قرارگرفت. اثر این پلیمر در کنترل میزان فرسایش بادی به صورت آزمایشگاهی و با تونل باد مورد بررسی قرار گرفت. نتایج نشان داد بین خاکهای تیمار شده با سطوح مختلف پلیمر، تفاوت معنیداری از نظر چگالی ظاهری وجود ندارد اما کاربرد پلیمر نسبت به تیمار شاهد باعث کاهش چگالی ظاهری نمونهها شد. کاربرد پلیمر مقاومت فروروی را به صورت معنیداری افزایش داد. همچنین بین دو سطح پلیمر تفاوت معنیداری وجود داشت. با گذشت زمان مقدار مقاومت فروروی خاک ابتدا افزایش و سپس کاهش یافت. مقاومت فروروی در روز 45ام به کمتر از مقاومت فروروی خاک در روز 15ام رسید. نتایج حاصل از آزمایشات فرسایش در تونل باد در شرایط باد با سرعت 12 متر بر ثانیه، نشانداد که افزودن ماده پلیمری پس از 30 روز در سطح 1 درصد میزان فرسایش بادی را در نمونههای ماسه بادی به صفر درصد کاهش داد.https://jsw.um.ac.ir/article_38575_218781cd8c7d2d28dfd00e64c587237d.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Study the Population of Iron and Sulfur Oxidizing Bacteria in the Soil of Miduk Cooper Mine in Shahrebabkبررسی جمعیت باکتریهای اکسید کننده آهن و گوگرد در خاک معدن مس میدوک شهربابک108310923857610.22067/jsw.v31i4.53663FAمهدی حسن شاهیانشهید باهنر کرمانسمیه قربانیواحد علوم و تحقیقات سیرجان، دانشگاه آزاد اسلامیJournal Article20160207Introduction: One of the most important indicators in relation to industry, economy and environment is to achieve the most recovery with the least cost and minimum pollution. Today, the use of chemolithotrophic microorganisms is common for extraction of some metals such as cooper, uranium, gold, cobalt and molybdenum in bioleaching process of low-grade rocks. Attention to the bioleaching of heavy metals such as copper, nickel, cobalt, zinc, and molybdenum has been increased in recent years because of its application to low-grade ores. The variety of microbes identified as being capable of growth in situations that simulate bio-mining commercial processes is rapidly growing. This is partly because of an increase in the number of environments being screened for such organisms, partly because of an increase in the variety of minerals being tested, and most importantly because of new techniques available to screen for the presence of organisms. The aim of the present research was to study the quantity of two important autotrophic bacteria, iron and sulfur oxidizing bacteria, in different regions of Miduk mine in Shahrbabak, Kerman province.
Materials and Methods The soil samples were collected from different locations of Miduk cooper mine such as: Sulfuric Pool Acid Discharge (PAD), Oxidic PAD, Sulfuric damp, Pool Leaching Sulfuric (PLS)and leaching hip. Top layer of mine soil (about 1 cm) was removed. In each site, soil samples were collected from five different spots. The quantity of iron and sulfur oxidizing bacteria were measured by culture of serial dilutions of samples in 9K medium with Iron and sulfur as electron sources, respectively. The 9K medium was used for enrichment of iron and sulfur oxidizing bacteria in collected mine samples. These two important groups of bacteria have autotrophic growth but the energy sources for these two bacteria are different. Iron oxidizing bacteria use ferrous ion in form of FeSO4 but sulfur oxidizing bacteria use inorganic sulfur and sulfur compounds as a source of energy and obtain the carbon from the reduction of the CO2 of the atmosphere, in autotrophic growth. Heterotrophic bacteria were quantified by culture in nutrient broth medium. Most probable number (MPN) method was used to enumeration the autotrophic and heterotrophic bacteria by culture of samples in 24 well microplates with specific medium. The positive index for enumeration iron and sulfur oxidizing bacteria in these experiments were red color and turbidity, respectively. The microplates were incubated for 21 days for autotrophic bacteria and 7 days for heterotrophic bacteria.
Results and Discussion: The results of this research showed that the highest quantity of heterotrophic bacteria related to soil near to PLS and the lowest quantity belonged to sulfuric PAD. Iron oxidizing bacteria had the highest density on oxidizing Pad (OP) and the lowest density of these bacteria found in soil near to PLS. The diversity of iron oxidizing bacteria was low in the mine. The lowest quantity of sulfur oxidizing bacteria related to oxidizing PAD. Although appropriate diversity of sulfur oxidizing bacteria in compare to iron oxidizing bacteria was observed in the Miduk mine. These results about quantity of iron oxidizing bacteria confirmed this truth that the presence of oxygen and also low acidity in oxidizing Pad (OP) has major effect on the distribution and quantity of iron oxidizing bacteria. Because, the optimum condition for growth of iron oxidizing bacteria is low acidity and abundance of oxygen that these two factors provided in oxidic Pad (OP).
The quantity of sulfur oxidizing bacteria was high in yellow soil near to PLS. These results obtained by enumeration with MPN and Newbar lam methods. This result can be interpreted as the high concentration of sulfur element in this region has a selection force to prevalent the sulfur oxidizing bacteria in compare to iron oxidizing bacteria in this region. Because, when the sulfur is high, the bacteria that can use this element as their only energy source for fixation of CO2 is dramatically increased.
Conclusions: In the present research, the quantity and distribution of iron and sulfur oxidizing bacteria of Miduk cooper mine were studied. Based on the results, iron and sulfur oxidizing bacteria had the highest density on oxidizing Pad (OP) and in yellow soil near to PLS, respectively. Although sulfur oxidizing bacteria had an appropriate diversity compared to iron oxidizing bacteria in Miduk mine. However, the results obtained in this study confirmed that the sufficient quantity of iron and sulfur oxidizing bacteria were present in this mine. Then, the soil bacteria of this mine can be used to enhance the bioleaching process in Miduk mine.یکی از شاخصهای مهم در ارتباط با صنعت، اقتصاد و محیط زیست دستیابی به بیشترین باز یابی با حداقل هزینه و کمترین میزان آلودگی است. امروزه استفاده از میکروارگانیزمهای کمولیتوتروف مزوفیل در استخراج فلزاتی چون مس، اورانیوم، طلا، کبالت و مولیبدن معروف به پدیده استخراج بیولوژی در سنگهای کم عیار معمول شده است. هدف از انجام این تحقیق شمارش دو دسته مهم از باکتریهای اکسید کننده آهن وگوگرد در مناطق مختلف معدن میدوک شهربابک در استان کرمان می باشد. برای دستیابی به این هدف از هفت نقطه مختلف معدن میدوک نمونههای خاک جمع آوری شد. تعداد باکتریهای اتوتروف اکسید کننده آهن و گوگرد با تهیه سریال رقت از نمونهها و کشت در محیط نه کی حاوی آهن و گوگرد عنصری بترتیب انجام شد. باکتریهای هتروتروف نیز با کشت در محیط نوترینت براث شمارش شدند. تعداد حداکثر احتمالی باکتریهای اتوتروف و هتروتروف نیز با کشت رقتهای اعشاری از نمونهها در محیط اختصاصی درون میکروپلیتهای 24 خانه انجام شد. نتایج حاصل از این تحقیق نشان داد که بیشترین میزان باکتریهای هتروتروف مربوط به YP نمونه خاک زرد رنگ نزدیک به تشتک PLS و کمترین تراکم باکتریهای هتروتروف در نمونهOP پد اکسیدی بود. بالاترین تراکم اکسیدکنندههای آهن مربوط به نمونه OP پد اکسیدی بود و کمترین تراکم نیز مرتبط به YP نمونه خاک زرد رنگ نزدیک به تشتک PLS بود. تنوع نسبتا پایینی در نمونههای معدن در خصوص اکسیدکنندههای آهن وجود داشت. بالاترین تراکم اکسید کننده های گوگرد مربوط بهYP خاکهای زرد رنگ اطراف تشتک PLS بود وکمترین تراکم باکتریهای اکسید کننده گوگرد مربوط به OP پد اکسیدی معدن بود. تنوع مناسبی از انواع اکسیدکنندههای گوگرد در معدن میدوک در مقایسه با اکسیدکنندههای آهن وجود دارد. با بکارگیری نتایج حاصله از این تحقیق و باکتریهای اتوتروف بدست آمده می توان جهت افزایش فرایندهای بیولیچینگ در معدن میدوک بهره برد.https://jsw.um.ac.ir/article_38576_6f66260309c3c2dccb612d8f93594051.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Sensitivity Analysis of FAO Penman-Monteith Model in Daily Reference Evapotranspiration Estimation and Zoning Sensitivity Coefficients across Iranتحلیل حساسیت مدل پنمن- مونتیث- فائو در برآورد تبخیرتعرق مرجع روزانه و پهنهبندی ضرایب حساسیت آن در گستره ایران104610593857310.22067/jsw.v31i4.57602FAفهیمه خادم پوردانشگاه باهنر کرمانبهرام بختیاریدانشگاه باهنر کرمان0000-0001-6555-4328سودابه گلستانیمهندسی منابع آب و استادیاران بخش مهندسی آب، دانشکده کشاورزی، دانشگاه شهید باهنرکرمانJournal Article20160718Introduction: In drainage and irrigation network capacity design and determination, reference evapotranspiration (ETo) plays significant role. Methods applied for estimated reference evapotranspiration classified in two direct and computational methods. Amongst computational methods it might point to Penman-Monteith method. This method requires radiation, temperature, humidity and wind speed data with high reliability rate in vast ranges of climates and areas represent precise outcome from reference plant Evapotranspiration.
Materials and Methods: Study stations in De Martonne classification system are divided into 6 climates such as Hyper-arid, Arid, Semi-arid, Mediterranean, Humid and Very humid (a) climates. Study stations statistical span during 19 years (1996-2015) were selected and temperature, relative humidity, sunshine hours, and wind speed in 2 meter height daily data were used. Figure 1 showed studied stations position all over the country. In this study, in order to obtain daily ETo, Penman-Monteith standard method represented by FAO-56 was used. In local sensitivity analysis, factors local influences on model output were shown. Such an analysis usually carried out through output functions minor deviants computation due to input variables. In this analysis, usually it was used one-factor- at-a- time method (OAT), so that, one variable factor and other input factors kept constant.
Figure 1. The geographical location of weather stations
The FAO-56 PM model for estimating ETo is as follows (3).
(1)
where ETo is reference crop evapotranspiration (mm day−1), Δ is the slope of vapor pressure versus temperature curve at temperature Tmean (kPa°C−1), γ is the psychometric constant (kPa °C−1), u2 is the wind speed at a 2 m height (m s−1), Rn is the net radiation at crop surface (MJ m−2 d−1), G is the soil heat flux density (MJ m−2 d−1), T is the mean daily air temperature at 2 m height (°C), and (es-ea) is the saturation vapor pressure deficit (kPa).
Results and Discussion: Weather parameters in stations showed that mean temperature sensitivity coefficient ( ) in all study stations varied between 0.21 to 0.78 so that the maximum temperature sensitivity coefficient related to Bushehr station in arid climate (in April, May, June, July, October and November) and minimum temperature sensitivity coefficient related to Shahrekordstation in semi-arid climate (in January, March, April and November). Maximum and minimum net radiation sensitivity coefficient value ( ) related to Rasht and Zahedanstations respectively. Also, maximum and minimum wind speed sensitivity coefficient value ( ) related to Zahedan and Ardebilstations are 0.54 and 0.07 respectively. Yazd station in Hyper-arid climate showed minimum relative humidity sensitivity coefficient value ( ) about 0.20 and Rasht station in very-humid (a) showed the maximum values 0.45. So the northern coastal areas are more sensitive to and SRH. The highest value is in northern coastal areas and lowest in southern coastal and southwest areas of the country. Some other studies showed that in many climates evapotranspiration was more sensitive to Rn (6, 14 and 17).In current study, also, showed the highest sensitivity in Very-humid climate (a) includes Rasht station in February, March, April, October and November. For example, = 0.82 means that 100% increase in Rn parameter result in 82% increase in ETo.
Conclusion: Sensitivity analysis experiment on FAO Penman-Monteith standard method is one of the most efficient methods to understand various climate parameters influence on reference evapotranspiration (ETo). In this study, results showed that computed ETo in all climates showed highest sensitivity to Rn and temperature respectively. Temperature sensitivity coefficient showed the highest value at April. May, June, July, October and November and Rn showed its highest value at March, April, October and November. While, minimum in all of months but May and July and maximum value showed in January, July, August and September by 0.07 and 0.54 respectively. So, in most months of the spring and the fall was larger and smaller during the winter months. Sensitivity coefficient related to mean temperature is higher during summer season and lower during winter season. Results of this study may be useful for assessing the response of the standardized FAO Penman-Monteith model in different climatic conditions. The results can also be used to predict changes in ETo values with respect to climatic variable changes obtained from climate change models.تبخیرتعرق (ET) تابع متغیرهای مختلف اقلیمی و ویژگی های توپوگرافی هر منطقه است. اولویت بندی و تعیین شدت تأثیر هر یک از این پارامترها بر روی تبخیرتعرق کمک شایانی به مدیریت منابع آب منطقه می نماید. در این مطالعه، تحلیل حساسیت مدل استاندارد پنمن- مونتیث- فائو در برآورد تبخیرتعرق مرجع (ETo) براساس متغیرهای اقلیمی میانگین دمای هوا (Tmean)، تابش خالص(Rn) ، مقاومت آئرودینامیک (ra) و کمبود اشباع (VPD) انجام پذیرفته است. ایستگاه های هواشناسی منتخب شامل 31 ایستگاه سینوپتیک در گستره ایران با دوره زمانی مشترک 19 ساله (2014-1996) می باشد. طبقه بندی اقلیمی ایستگاه ها نشان داد که از این تعداد ایستگاه مورد بررسی، 3 ایستگاه در اقلیم فراخشک، 10 ایستگاه در اقلیم خشک، 13 ایستگاه در اقلیم نیمه خشک، 2 ایستگاه در اقلیم مدیترانه ای، 2 ایستگاه در اقلیم مرطوب و 1 ایستگاه در اقلیم بسیار مرطوب (الف) قرار دارند. ضرایب حساسیت برای هر یک از متغیرها در مقیاس زمانی روزانه با استفاده از روش مشتقات جزئی و تحلیل حساسیت محلی محاسبه گردید. سپس پهنه بندی ضرایب حساسیت با استفاده از روش عکس مجذور فاصله (IDW) تهیه شد. نتایج نشان داد که ETo محاسبه شده در تمامی اقالیم، به میانگین ضریب حساسیت تابش خالص (0.999) (SRn) بسیار حساس بوده در حالی که به میانگین دما در اقلیم های فراخشک، نیمه خشک، خشک و مدیترانه ای طی ماه های ژوئیه، اوت، سپتامبر و اکتبر حساس است. کمترین مقدار ضریب حساسیت مقاومت آئرودینامیک (Sra) در روز جولیوسی 331 منطبق بر26 و 27ام نوامبر (آذر ماه) و بیشترین آن در روز 340 منطبق بر 5 و 6ام دسامبر (دی ماه) بوده است. این ضریب حساسیت در طی ماه های زمستان بزرگتر و طی ماه های تابستان کوچکتر بود، در حالی که کمترین و بیشترین مقدار ضریب حساسیت کمبود اشباع (SVPD) در ماه دسامبر به ترتیب با مقادیر 0.008- و 0.032 می باشد. ضریب حساسیت Tmean در کلیه ایستگاه های مطالعاتی طی ماه های تابستان بزرگتر و طی ماه های زمستان کوچکتر بود.https://jsw.um.ac.ir/article_38573_0158dc984c7b00c4fa0e9db0273391ed.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Effectiveness Comparison of Pot, Porous Pipe and Gravity Drip Irrigation Methods in the Range of Gravity Pressuresمقایسه کارائی روشهای آبیاری کوزهای، قطرهای ثقلی و تراوا در محدوده فشارهای ثقلی106010693857410.22067/jsw.v31i4.60460FAمجید عرب فردساریعلی شاهنظریعلوم کشاورزی و منابع طبیعی ساری0000-0003-1135-8174میرخالق ضیاتبار احمدیدانشگاه کشاورزی و منابع طبیعی ساریJournal Article20161121Introduction: Practical problems such as rushing roots toward pot, difficulty of manually filling with water and deficit irrigation due to permeation from regular pots prevents the development of pot irrigation. With regard to increasing irrigation efficiency importance and preventing water loss to fix the problems of this irrigation method.Changing physical structure of pot could solve many problems and issues which this irrigation technique is facing. Comparison of the two major characteristics of localized irrigation hydraulic characteristics (coefficient of variation and distribution uniformity) and also using gravity pressure can achieve a solution for water and energy shortage problems. So far, with knowledge of the role of water pressure at gravitational pressures in hydraulicproperties of these methods, some effective features in these methods application is specified.
Material and Methods: This study was carried out in randomized complete block at water engineering department of Sari Agriculture Science and Natural Resources university laboratory from September to December 2015. In this study, in the form of randomized complete block, hydraulic specifications of three treatments of pot irrigation, gravity drip irrigation and porous pipe irrigation investigated under water pressure of 0.5, 1.5 and 3 m. In each of the water column pressure, output water volume from 10 samples of each irrigation method treatments calculated from 7 replicates during one hour in about two months. Porous pipes which used in this study were imported 16mm sample pipes from Anahita Company. GDI gravitational emitter model, porous pipe and containers made of cellulose clay pots in the form of cylinder shape with diameter of 15 cm were used. Thus, within one hour of irrigation, water volume withdrawn from tested samples under constant pressure of irrigation were collected by suitable containers and measured by graded container and flow rate of each samples were calculated. Christensen distribution uniformity coefficient was calculated with Christensen distribution uniformity coefficient formula. Based on USA agronomical engineers, a pointed emitters with variation coefficient less than 0.05 is good, with cv of 0.05-0.10 is medium and with cv of 0.10-0.15 is weak. After calculating evaluation parameters, the results were analyzed with SPSS statistical software and Tukey test at 1 %and 5 % level of probability.
Results and Discussion: The results of statistical analysis of randomized complete block design and mean comparison of different level of treatments effects with Duncan test (irrigation method treatment and water pressure treatment) at 5 %level of probability showed that maximum distribution uniformity achieved in gravitational drip irrigation among samples. With increasing pressure, coefficient of variation was less affected and at lower pressures, coefficient of variation among tested samples were more evident. In addition, it is indicated that increasing pressure have maximum effect on flow rate and distribution uniformity increment while with increasing pressure, minimum changes observed in coefficient of variation. Therefore, among possible gravitational pressures in each project, maximum pressure should be selected for design and implementation. Result showed that in porous pipes and in pressures of 50, 150 and 300 cm, average flow rate were 0.31, 1.4 and 4.2 liter per hour in meter, average coefficient of variation were 0.88, 0.61 and 0.83 and average distribution uniformity were 2.2, 6.2 and 1.6 percent, respectively. In the main-treatment and in each pressure sub-treatment, samples flow rate changes at different replicates is so high that coefficient of variation was more than conventional coefficient (more than 0.6) and thus classified in unacceptable emitters. In this treatment, distribution uniformity was so low that using this irrigation method at gravitational pressures range cannot be recommended. Based on statistical analysis results, it is indicated that increasing pressure in gravitational drip irrigation have maximum effect and in pot irrigation, have minimum effect on flow rate changes, and in addition, maximum distribution uniformity among samples was in gravitational drip irrigation while in porous pipe irrigation besides high coefficient of variation, minimum distribution uniformity among samples were observed.
Conclusion: Due to the high influence of pressure changes in gravitational pressures on hydraulic characteristics of mentioned three irrigation method, among investigated gravitational pressures in this study, pressure of 3m as appropriate pressure at gravitational pressures and among localized irrigation methods, gravitational drip irrigation were recommended. It is recommended to paying attention to the development of gravitational drip irrigation application in large-scale garden and agriculture projects with positive approach.مشکلات اجرای آبیاری کوزهای همچون هجوم ریشه گیاه به سمت کوزه و مشکل پرکردن دستی کوزهها از آب، مانع از توسعه کاربرد این روش آبیاری شده است. لذا بررسی کارایی روش جایگزین آبیاریکوزهای مانند آبیاری تراوا وقطرهایثقلی، میتواند به عنوان راهکاری برای برونرفت از معضل توأمان کمبود آب و انرژی مطرح شود. به این منظور تحقیقی آزمایشگاهی با هدف شناسایی خصوصیات هیدرولیکیاین سه روش آبیاری انجام شد. در این تحقیق در قالب طرح آزمایشی بلوکهای کامل تصادفی،برخی از مشخصات هیدرولیکی سه تیمار روش آبیاری فوقالذکردر سه فشار آب 5/0 متر، 5/1 متر و 3 متر بررسی شد و با اندازهگیری حجم آب خارجشده تحت فشار ثابت آبیاریدر مدت یکساعت، دبی 10 نمونه از هر تیمار،در طی هفت تکرار محاسبه شد و نتایج حاصله با استفاده از نرمافزار آماری SPSS مورد تجزیه و تحلیل قرار گرفت. بر اساس نتایج تجزیه واریانس، مشخص شد که بیشترین یکنواختی توزیع بین نمونهها در آبیاری قطرهای ثقلی بوده و در آبیاری تراوا ضمن بالابودن ضریب تغییرات ساخت، کمترین یکنواختی توزیع بین نمونهها مشاهده شده است. همچنین با مقایسه میانگین اثر سطوح فشار آبیاری در یکنواختی توزیع در سطح احتمال پنج درصد به روش دانکن، مشخص شد که با افزایش فشار، یکنواختی توزیع بیشتر خواهد شد. لذا به جهت حفظ یکنواختی توزیع بالاتر پیشنهاد میشود که بیشترین فشارثقلی جهت طراحی و اجرا انتخاب شود.در این تحقیق طی دو ماه کارکرد تیمارها،به طور متوسط دبی لوله تراوا کم شد و با افزایش ضریب تغییرات ساخت و کمشدن یکنواختی توزیع، عملکرد ضعیف این روشآبیاری در محدوده فشارهای ثقلی نتیجه گرفتهشد. این در حالی است که تیمار قطرهایثقلی در کلیه تکرارها از ثبات مشخصات هیدرولیکی برخوردار بوده و در تیمار کوزهای نیز حتی با گذشت زمان، دبی نمونهها به طور متوسط افزایش یافته است. لذا با منظورکردن پایینبودن ضریب تغییرات ساخت و بالابودن یکنواختی توزیع به عنوانمشخصههای برتری هیدرولیکی، از بین سه روش مذکور به ترتیب روش آبیاری قطرهایثقلی، روشآبیاریکوزهای و روش آبیاریتراوا و از بین فشارهایثقلی مورد بررسی نیز، فشار 3 متر به عنوان فشار مناسب توصیه میشوند.https://jsw.um.ac.ir/article_38574_fbf0edbc64693cff2272fb9144027ddd.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Modeling the Effects of Climate Change on Irrigation Requirement and Water Use Efficiency of Wheat Fields of Khuzestan Provinceمدل سازی اثرات تغییر اقلیم بر نیاز آبیاری و کارایی مصرف آب در گندمزارهای استان خوزستان101510303857110.22067/jsw.v31i4.58046FAرضا دیهیم فردگروه کشاورزی اکولوژیک، پژوهشکده علوم محیطی، دانشگاه شهید بهشتی، تهران، ایرانحامد عینی نرگسهگروه زراعت، دانشکده کشاورزی، دانشگاه تربیت مدرس، تهران، ایرانشبنم فرشادیگروه کشاورزی اکولوژیک، پژوهشکده علوم محیطی، دانشگاه شهید بهشتی، تهران، ایرانJournal Article20160808Introduction: One of the most important consequences of the future climate change is its impact on water use and water use efficiency (WUE) in agriculture which could challenge the water resources management. Khuzestan province is one of the most important areas of crops production in Iran particularly for wheat, so that 15.73 percent of total irrigated wheat production and 8.85 percent of total arable land is located in this province. Therefore, investigating climate change effects on irrigated wheat production, WUE and irrigation requirement will be necessary in the Khuzestan province. In this context, this study was conducted to simulate the growth and yield of irrigated wheat under climate change conditions, and to calculate WUE and irrigation requirement in this province.
Materials and Methods: The current study was done at six locations of Khuzestan province in southwestern Iran, included Ahwaz, Behbahan, Dezful, Izeh, Omidiyeh and Ramhormoz. Historical daily weather data including solar radiation (MJ m-2 d-1), precipitation (mm) and maximum and minimum temperatures (˚C) for the baseline period gathered for each study location from their established meteorological stations. To predict the climatic variables in the future, HadCM3 climate model was applied under three emission scenarios (B1, A1B and A2) for one future time period (2046-65). The observed historical daily weather data at each location was used to generate the future scenario files to be applied in LARS-WG (Long Ashton Research Station-Weather Generator) program. These parameters are necessary for future projection of weather variables. The downscaled daily weather data obtained from the LARS-WG included maximum and minimum temperatures, rainfall and solar radiation for each period of future climate. These data are required for running crop simulation model. The Agricultural Production Systems simulator (APSIM) was used to predict the impacts of climate change on wheat yield, WUE and irrigation requirement. The model requires daily weather variables (maximum and minimum temperatures, precipitation and solar radiation), soil properties, type of genotype (as cultivar-specific parameters), and crop management information as inputs to simulate crop growth and development. In order to evaluate the climate model NRMSE (Normalized Root Mean Square Error) index was used. Finally, the outputs obtained from the model simulation experiments were analyzed using excel, SAS and Sigma Plot.
Results and Discussion: Results of climate model evaluation indicated that LARS-GW well predicted radiation (NRMSE from 0.63 to 1.67%), maximum (NRMSE from 0.63% to 1.05%) and minimum (NRMSE from 0.63% to1.97%) temperatures. However, the accuracy in prediction of rainfall (NRMSE from 11.42% to 21.47%) was not as good as the other climatic variables. The simulation results in the baseline by APSIM-Wheat showed that maximum and minimum grain yield were obtained in the Izeh (6764.2 Kg.ha-1) and Omidiyeh (5230.2 Kg.ha-1), respectively. Under climate change conditions (rising temperature and elevated CO2), on average, the highest and lowest grain yield were obtained in Izeh (7755.3 Kg.ha-1) and Omidiyeh (6290.76 Kg.ha-1), respectively. The simulation results in the baseline also indicated that the highest and lowest evapotranspiration (ET) were obtained in the Izeh (441.7 mm) and Ramhormoz (401.5 mm), respectively. When averaged across all future scenarios, the maximum and minimum ET were obtained in Izeh (409.56 mm) and Ramhormoz (375.38 mm), respectively. The future rising temperature will intensify the ET, whereas reducing stomata conductance due to higher CO2 concentration in one hand, and shortening growing period due to rising temperature on the other hand, will reduce the cumulative ET in wheat. The simulation results in the baseline showed that the highest and lowest WUE were obtained in Izeh (15.32 Kg.ha-1.mm-1) and Omidiyeh (12.7 Kg.ha-1.mm-1), respectively. In climate change conditions (rising temperature and CO2 elevated), on average the highest and lowest WUE were obtained in Izeh (18.93 Kg.ha-1.mm-1) and Omidiyeh (15.76 Kg.ha-1.mm-1), respectively. Wheat crop would be benefitted under future climate change in Khozestan province as it is a C3 plant, and under optimal conditions (no water and nitrogen limitations), it will produce more grain because of reduced stomata conductance and increased photosynthesis and WUE owing to elevated CO2. Simulation results also indicated that under climate change conditions, on average, the highest and lowest irrigation requirement were obtained in Ahwaz (315.39 mm) and Izeh (225.96 mm), respectively. The reduced irrigation requirement of wheat under climate change conditions could be attributed to decreasing length of growing season and increasing CO2 concentration.
Conclusion: In the current study, the effects of climate change caused by rising temperature and elevating CO2 concentration on WUE, irrigation requirement, growth and yield of wheat were investigated in the Khuzestan province. The simulation results showed that, wheat grain yield under climate change conditions (averaged across all scenarios) will increase by 16 % compared to the baseline. In addition, WUE will be increased 23 percent owing to increasing grain yield (+16%) and decreasing ET (5%) under different scenarios. Overall, under climatic conditions of Khuzestan province in 2046-2065, WUE would be increased by 23% and irrigation requirement would be decreased by 9%. The reasons behind these increases and decreases are rising temperature (7%), elevating CO2 concentration (up to 526 ppm for 2046-65) and decreasing the length of growing season and ET both by 5%.یکی از مهمترین پیامدهای تغییر اقلیم آینده، تأثیر آن بر مصرف آب در بخش کشاورزی است که میتواند مدیریت منابع آب را با چالشهای جدی روبرو سازد. در این مطالعه بهمنظور پیشبینی اثرات تغییر اقلیم بر رشد و نمو گندم در شش شهرستان استان خوزستان شامل اهواز، بهبهان، دزفول، ایذه، رامهرمز و امیدیه از مدل گردش عمومی HadCM3تحت سه سناریوی B1،A1Bو A2در دوره 65-2046 استفاده شد. برای ریزمقیاس کردن پارامترهای اقلیمی مولد آب و هوایی LARS-WG مورداستفاده قرار گرفت. پس از شبیهسازی اقلیم آینده و تولید پارامترهای موردنیاز، شبیهسازی رشد و نمو گندم با استفاده از مدل APSIM-Wheat انجام شد. نتایج ارزیابی مدل LARS-WG با استفاده از شاخص NRMSEحاکی از دقت بالای مدل در شبیهسازی تابش (از 63/0درصد تا 67/1 درصد)، دمای کمینه (از 63/0 درصد تا 98/1درصد) و بیشینه (از 63/0 درصد تا 05/1 درصد) بود درحالیکه مقدار این شاخص برای بارندگی (از 42/11درصد تا 47/25 درصد) در مقایسه با دیگر متغیرها بالاتر بود. نتایج شبیهسازی نشان داد که در استان خوزستان عملکرد دانه گندم در شرایط تغییر اقلیم نسبت به دوره پایه بهطور میانگین 16 درصد افزایش مییابد. با افزایش عملکرد دانه و همچنین کاهش تبخیر-تعرق (کاهش 5 درصدی در مقایسه با دوره پایه) در شرایط تغییر اقلیم، کارایی مصرف آب 23 درصد افزایش مییابد. به طور کلی نتایج این تحقیق نشان داد که با توجه به افزایش دما (7 درصد)، افزایش غلظتCO2(از 334 پیپیام به 526 پیپیام در سال 2050)، کاهش طول فصل رشد (74/7 روز) و کاهش تبخیر-تعرق نیاز آبیاری گندم در شرایط تغییر اقلیم آینده 9 درصد کاهش مییابد.https://jsw.um.ac.ir/article_38571_98d8b77bc41d3deb6d7f8e5b691707bd.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Application of Archimedean and Extreme values Copula Functions for Multivariate Analysis of Low Flows in Dez Basinکاربرد توابع مفصل ارشمیدسی و حدی در تحلیل چند متغیره جریانهای کمینه حوضه آبریز دز103110453857210.22067/jsw.v31i4.58373FAفرشاد احمدیدانشگاه شهید چمران اهواز0000-0001-7387-0224فریدون رادمنشدانشگاه شهید چمران اهوازغلامعلی پرهامگروه آمار، دانشگاه شهید چمران اهوازرسول میرعباسی نجف آبادیگروه مهندسی آب، دانشگاه شهرکرد0000-0002-9897-0042Journal Article20160823Introduction: Hydrological phenomena are often multidimensional and very complex. Hence, the joint modeling of two or more random variables is required to investigate the probabilistic behavior of them. To this aim, the copulas can be efficiently utilized to derive multivariate distributions. In addition, the copula functions can quantify the dependence structure between correlated random variables. Estimation of low flow is necessary in different fields of hydrological studies such as water quality management, determination of minimum required flow at downstream for producing electricity and cooling purposes, design of intakes, aquaculture, design of irrigation systems and assessing the effect of long-term droughts on ecosystems. Low flows can be determined based on low flow indices. There are many types of low flow indices which among them the 7-days low flow with different return periods are more popular. Heretofore, numerous studies have been performed in the field of univariate analysis of river low flows, but the low flows of two river branches can be simultaneously analyzed using copula functions. Copula is a flexible approach for constructing joint distribution with different types of marginal distributions. Indeed, the copula is a function which links univariate marginal distributions to construct a bivariate or multivariate distribution function.
Materials and Methods: Hydrological phenomena often have different properties, where for their frequency analysis; they may be examined either individually or concurrently. These variables are not independent, rather they are interconnected and the change in one of them affects the other. Thus, the univariate frequency analysis can bring about some error due to neglecting the interdependence between these random variables. the copula is a function which joint the marginal distribution functions for constructing a bivariate or multivariate function. Development of copula functions is alleged to Sklar (1959) who described how univariate distribution can be jointed to form a multivariate distribution. Generally a copula function is a transfer of a multivariate function from to . This transfer separate marginal distributions from F function and the copula function, C, is only related to dependency among variables, therefore it present a full description of inner dependency structure. In other words, the Sklar’s theorem states that for multivariate distributions, the inner dependency among the variables and univariate marginal distributions is separated and the dependency structure explained by copula function. The copula function divided into many families which among them then the Archimedean copula is widely used in multivariate analysis of hydrological events and also has an explicit formula for its cumulative form which is an important advantage in comparison with elliptical copula functions that have not explicit formula. Application of the copulas can be useful for the accurate multivariate frequency analysis of hydrological phenomena. There are many copula functions and some methods were proposed for estimating the copula parameters. Since the copula functions are mathematically complicated, estimating of the copula parameter is an effortful work. In this study, five different copula functions including, Ali - Mikhail – Haq, Clayton, Frank, Gal ambos and Gumbel-Hougaard were used for multivariate analysis of 7-days low flow in Dez basin.
Results and Discussion: In this study, the low flow of the Dez basin at junction of river branches during 1956-2012 were investigated using copula functions. For this purpose, firstly the 7-days low flow series of considered stations were extracted and then the homogeneity of the series was examined using Mann-Kendall test. The results showed that the 7-days low flow series of Dez basin are homogenous. In the next step, 11 different distribution functions were fitted on low flow series and the Logistic distribution was selected as the best fitted marginal distribution for considered stations. After specifying the marginal distributions, the Archimedean and Extreme value families of copula functions were used for multivariate frequency analysis of 7-days low flow. For this study, the best-fitted copula was specified in two ways. For the first specification, the nonparametric empirical copula was computed and compared with the values of the parametric copulas. The parametric copula that was closest to the empirical copula was defined as the most appropriate choice. The second specification was based on the statistical approach. The results indicated that for pair data of Sepid Dasht Sezar and Sepid Dasht Zaz stations, the Gumbel-Hougaard copula had the most accordance with empirical copula. In order to investigate the joint return periods, we used the joint return periods in two cases of AND and OR forms and also conditional joint return period.
Conclusion: Based on the obtained results from joint analysis of the low flow at upstream of the junction of two river branches, it was specified that two river branches of Sepid Dasht Sezar and Sepid Dasht Zaz may experience sever simultaneous drought events every 200 years.تحلیل فراوانی جریانهای کمینه به منظور برنامهریزی جهت تامین نیازهای مختلف، مدیریت کمی و کیفی جریان رودخانه و بررسی خصوصیات و تاثیر خشکسالیها بر اکوسیستم آبی منطقه از اهمیت ویژهای برخوردار است. با وجود ماهیت پیچیده کمآبیها اکثرا از روشهای تک متغیره به منظور تحلیل فراوانی جریانهای کمینه استفاده شده است. در این مطالعه جریانهای کمینه حوضه آبریز دز در دوره آماری 1391- 1335 با استفاده از توابع مفصل در محل اتصال سرشاخهها مورد بررسی قرار گرفت. بدین منظور ابتدا سریهای هفت روزه جریان کمینه در ایستگاههای مورد مطالعه استخراج و سپس همگنی آنها با استفاده از آزمون من- کندال بررسی شد. نتایج نشان داد که سریهای جریان کمینه هفت روزه حوضه آبریز دز همگن بود. در مرحله بعد، 11 تابع توزیع مختلف به دادههای جریان کمینه برازش داده شد و در نهایت توزیع لجستیک به عنوان توزیع حاشیهای مناسب ایستگاههای مورد مطالعه انتخاب گردید. پس از انتخاب توزیع حاشیهای، از توابع مفصل خانوادههای ارشمیدسی و حدی برای تحلیل فراوانی توام جریان کمینه هفت روزه استفاده شد. نتایج نشان داد که مفصل گامبل- هوگارد برای جفت دادههای ایستگاههای سپید دشت سزار و سپید دشت زاز بیشترین تطابق را با تابع مفصل تجربی داشته است. برای بررسی دوره بازگشت وقایع در حالت توأم، از دوره بازگشت توأم در دو حالت «یا» و «و» و دوره بازگشت توأم شرطی استفاده شد. براساس نتایج به دست امده از تحلیل توام جریان کمینه دو سرشاخه متصل به هم مشخص شد که دو رودخانه سپید دشت سزار و سپید دشت زاز به طور متوسط هر 200 سال یکبار به صورت همزمان میتواند در معرض خشکسالی شدید قرار گیرد.https://jsw.um.ac.ir/article_38572_93e7186d8756f0740998e592d3a90cd2.pdfدانشگاه فردوسی مشهدآب و خاک2008-475731420171023Effect of Different Irrigation Levels and Cultivation Techniques on Water Use Efficiency and Quantity and Quality yield of Sweet Corn (Zea mays var. saccharata)تاثیر سطوح مختلف آبیاری و روشهای کشت بر بهروری مصرف آب و عملکرد کمی وکیفی ذرت شیرین (Zea mays var. saccharata)100110143857010.22067/jsw.v31i3.53661FAمحمد جواد فریدونیگروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه یاسوجهوشنگ فرجیگروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه یاسوجJournal Article20160208Introduction: In Iran, due to reduction of water resources and increasing of water losses in the various methods of the surface irrigation pressurized irrigation methods, especially drip irrigation have got many attentions. Application of the plastic mulch method is used in cultivation of early sweet corn. Application of this technique due to its temperature provides both plant growth and early maturity and then causes the on-time delivery of product to the target market. Additionally, to reduce water consumption, the use of germinated seedlings in the greenhouse and move it under plastic on the farm, productivity will increase. The aim of this study was to evaluate irrigation levels on yield of sweet corn by using plastic mulch, and the feasibility of seedling cultivation to early crop.
Materials and Methods: In order to evaluate the effect of different irrigation levels and cultivation techniques on water use efficiency and quality and quantity yield of sweet corn, an experimental program was carried out as split plot in randomize complete blocks design with three replication in Faculty of Agriculture, Research Field Station of Yasouj University in 2015. The main factor consisted of three levels of irrigation: 100 (I1), 75 (I2) and 50 percentage of water requirement (I3) and the sub-factor was including cultivation techniques of sweet corn in six levels: seed cultivation of sweet corn under plastic mulch on 4 April (CT1), seedling cultivation under plastic mulch on 4 April (CT2), seed cultivation to conventional method of sweet corn on 5 May (CT3), seed cultivation of sweet corn under plastic mulch on 5 May (CT4), seedling cultivation of sweet corn under plastic mulch on 5 May (CT5) and seedling cultivation to conventional method of sweet corn on 5 May (CT6).
In order to establish plastic mulch, after seed and seedling cultivation of sweet corn with installation of irrigation tape tubes, steel bars which were made in a semi-circular shape, were placed on rows and plastics were laid on it. After the establishment of the seedling on the farm, the irrigation levels were applied by volumetric counters. When the plant height was equal to the height of plastic tunnels, it was tried to pierce the plastic to grow suitability. During the time of maturity product, a 2 m2 plot in the middle of farm was selected and the ears were separated and weighed, and the forage yield was weighted. The grains of sweet corn were separated and canned yield was measured. The content of grain sugar, sucrose and fructose were measured by means of HPLC method, and the content of grain nitrogen with using of micro Kjeldahl’s method achieved. Statistical analysis was performed using SAS software. The mean values were compared by using LSD multiple range tests at 5% level. Figures were depicted by using of Excel software.
Results and Discussion: The results indicated that irrigation interaction and cultivation techniques were significant on ear yield, the canned yield, water use efficiency, and forage yield. The maximum ear yield obtained in treatments of I2CT1, I1CT1, I2CT2 and I1CT2 were equal to 14420, 14414.4, 13691.7 and 13513.5 kg ha-1, respectively and the maximum water consumption content for mentioned treatments were equal to 2521, 3362, 2385 and 3180 m3 ha-1, respectively. The minimum ear yield obtained in treatment of I3CT3 was equal to 706 gm-2. Water stress delayed the physiological processes including silk rating and tassel emergence, so that, it reduced growth and plant height and finally leaded to the reduction of grain yield. The maximum canned yield were obtained in treatment of I1CT1, I2CT1, I1CT2 and I2CT2 equal to 558.7, 551.1, 536.2 and 527.4 gm-2, respectively. Higher grain yield of sweet corn under plastic mulch in comparison with non plastic mulch, was due to increasing of dry matter accumulation before the silk production. It seems that increasing temperature and water content under plastic mulch resulted in an increase in grain dry matter accumulation. The maximum water use efficiencyfresh grain was obtained in treatment of I2CT2, I2CT1, I3CT2 and I3CT1 equal to 2.21, 2.18, 2.16 and 2.14 kgm-3, respectively. With increasing of water consumption water use efficiencyfresh grain decreased. Maximum forage yield was obtained in I1CT1 equal 2008 gm-2 and minimum forage yield was obtained in I3CT6 equal 1237 gm-2. Available water under plastic mulch, increased plant growth by increasing of leaf area index and shoot biomass due to stomata opening.
The effect of irrigation were significant on grain sucrose percentage, and content of protein. Moreover cultivation techniques effect was also significant on content of grain sugar, sucrose percentage and subsequently the content of grain protein. The maximum grain sucrose percentage was for treatment of 100% water requirement of sweet corn which was equal to 4.92%. Treatment of 75 percentage water requirement, also, the minimum grain sucrose percentage equal to 4.11% was obtained in treatment of 50 percentage water requirement. Retaining of moisture increased the amount of sugar and grain sucrose content. The maximum content of grain protein was equal to 11.41% in treatment of 100 percentage water requirements; also the minimum content of grain protein equal 8.58% was obtained in treatment of 50 percentage water requirement.
By reducing soil moisture, the content of protein and sugar grain increased, so the maximum content of grain protein and sugar were obtained in treatment of 50 percentage water requirement, although the maximum levels of irrigation reduced the content of protein and sugar. Under stress conditions, the plant material requirement is not enough, so by reducing nutrient transport, the leaf and stem cell development delayed, resulting in reduced plant height, leaf area, the content of grain protein, sugar. Finally, dry matter accumulation in the grain decreases with the transfer of nutrients from the leaves, and then it caused early death the leaf.
Conclusions: Application of seedling and plastic mulch accelerated plant growth, its development and then it was out of season production. If there are not water restrictions, application of treatment of 100 percentage water requirement of sweet corn with plastic mulch is desirable to maximum yield produce. Average of water consumption was in treatments of plastic mulch and non-plastic mulch equal to 2735 and 3411 m3 respectively. Maximum content of grain protein and sucrose percentage were obtained in treatments contains plastic mulch. Seedling cultivation in comparison with seed cultivation showed minimum content of grain sugar and grain sucrose percentage. In order to achieve the maximum quality and quantity yield in areas that are faced to water restriction, it is possible to use treatment of 75 percentage of water requirement and seeding cultivation under plastic mulch.به منظور بررسی اثر سطوح مختلف آبیاری و روشهای کشت بر بهروری مصرف آب و عملکرد کمی و کیفی ذرت شیرین، آزمایشی به صورت کرتهای خردشده در قالب طرح بلوکهای کامل تصادفی با 3 تکرار در مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه یاسوج در سال 1394 اجرا گردید. عامل اصلی آزمایش شامل آبیاری در 3 سطح، 100 (1I)، 75 (2I) و 50 درصد نیاز آبی گیاه (3I) و عامل فرعی شامل روشهای کشت در 6 سطح، کشت بذر زیر خاکپوشه پلاستیک در 15 فروردینماه (1CT)، کشت نشا زیر خاکپوشه پلاستیک در 15 فروردینماه (2CT)، کشت بذر به روش متداول در 15 اردیبهشتماه (3CT)، کشت بذر زیر خاکپوشه پلاستیک در 15 اردیبهشتماه (4CT)، کشت نشا زیر خاکپوشه پلاستیک در 15 اردیبهشتماه (5CT) و کشت نشا به روش متداول در 15 اردیبهشتماه (6CT) بودند. نتایج نشان داد که برهمکنش آبیاری و روشهای کشت بر صفات عملکرد بلال و بهروری مصرف آب معنیدار گردید. بیشترین عملکرد بلال در تیمارهای 1CT2I، 1CT1I، 2CT2I و 2CT1I به ترتیب معادل 14420، 4/14414، 7/13691 و 5/13513 کیلوگرم بر هکتارو میزان مصرف آب در تیمارهای مذکور به ترتیب معادل 2521، 3362، 2385 و 3180 متر مکعب بر هتار بود. عملکرد بلال در تیمارهای کشت نشا در مقایسه با تیمارهای کشت بذر و همچنین تیمارهای خاکپوشه در مقایسه با تیمارهای بدون خاکپوشه به ترتیب حدود 85/2 و 80/27 درصد افزایش یافت. بیشترین بهروری اقتصادی مصرف آب در تیمارهای 2CT2I، 1CT2I، 2CT3I و 1CT3I به ترتیب معادل 21/2، 18/2، 16/2 و 14/2 کیلوگرم بر مترمکعب بدست آمد. استفاده از نشا و خاکپوشه پلاستیک باعث تسریع رشد و نمو گیاه و تولید خارج از فصل شد.حفظ رطوبت زیر خاکپوشه پلاستیک، باعث افزایش میزان قند و درصد ساکارز دانه گردید. در مناطقی که محدودیت آب وجود دارد، جهت رسیدن به حداکثر عملکرد کمی و کیفی، استفاده از تیمار تامین 75 درصد نیاز آبی گیاه و کشت نشا زیر خاکپوشه امکانپذیر است.https://jsw.um.ac.ir/article_38570_3f15c35760430fa76762fe0576ec4add.pdf