Research Paper
h kh
Abstract
Azotobacter is a gram negative, aerobe, chemo-organotroph with the, polymorphism including rod, cocci and ovoid forms. This bacterium belongs to gama-proteobacteria class, Pseudomonaceae family with 7 species. It cannot produce spores but forms cyst. Azotobacters’species lives in different regions ...
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Azotobacter is a gram negative, aerobe, chemo-organotroph with the, polymorphism including rod, cocci and ovoid forms. This bacterium belongs to gama-proteobacteria class, Pseudomonaceae family with 7 species. It cannot produce spores but forms cyst. Azotobacters’species lives in different regions from tropicals to poplars in pH 3-9. However, it can be fined mainly in alkaline and natural soils. Azotobacter is able to fix non-symbiotically molecular nitrogen. It can synthesize aminoacids, plant growth hormones, vitamins, and exo-polysaccharides. The population of Azotobacter in soils is lower than 104 cells per gram of soil. The number of Azotobacter in some soils of Iran is about 1.5×103. Azotobacter affect the plant growth by nitrogen fixation, producing plant growth promoting hormones, solubilizing inorganic phosphates, increasing nutrients uptake, increasing resistance to stress conditions and biocontrol of plant pathogen agents. Some species of Azotobacter are able to remediate some contaminants. There are many reports about significant effects of Azotobacter inoculation on different plants e.g. cereals, vegetables and fruit trees. There are some constraints on the extension of traditional production of Azotobacter inoculants such as low organic matter in many soils, uncertainty in reproducibility and effectiveness and lack of competitiveness with chemical fertilizers for yield increasing. However, long life of Azotobacter in soils and inoculum packages and ability to use for many ranges of plants are the most important of its comparative advantages. Accumulation of plant growth stimulating characteristics in certain strain and creating the ability of symbiotic relation with plants e.g. cereals by molecular studies is recommended for future investigations.
Research Paper
k k
Abstract
This study was conducted to investigate the characteristics of input and output wastewater of the Bandargaz wastewater treatment plant on the basis of the data collected during operation and the samples taken during the study period. For this purpose, three samples were taken from the outflow wastewater ...
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This study was conducted to investigate the characteristics of input and output wastewater of the Bandargaz wastewater treatment plant on the basis of the data collected during operation and the samples taken during the study period. For this purpose, three samples were taken from the outflow wastewater and 25 quality parameters were tested. Also, four soil samples were taken from the soils which were from a depth of 0-30 cm irrigated soil with wastewater in the beginning and middle of the planting season Two soil samples were also from adjacent landsnot irrigated with waste water and analyzed for their chemical and physical properties.Double ring method was used for measuring the soil infiltration rate. The results obtained showed that the treated wastewater suitable for irrigation based on standards and criteria of American salinity laboratory (1954), Ayers and Westcot Guide (1985), Manual of Water in India (1992), Iranian guide for Water Quality Classification (Neyrizi, 1999), Iranian standard of urban wastewater treatment output (2008), handbook No. 535 ministry of Energy (2011) and Australian Guideline CSIRO (1999). In comparison with fresh water, mid-term use of treated wastewater did not caused the restrictions on soil in aspect of salinity and sodium rate on the basis on Richards (1954), Shainberg and Oster (1978), Rhodes et al. (1992), American salinity laboratory (1954) and Iranian guide for the irrigated lands classification.
Research Paper
h a; n n; e m
Abstract
The study of World Health Organization (WHO) has shown that the use of herbal medicines has been increased dramatically around the world in recent years. With the expanding popularity and trade of medicinal plants, health, safety and quality of medicinal plant raw materials and processed products have ...
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The study of World Health Organization (WHO) has shown that the use of herbal medicines has been increased dramatically around the world in recent years. With the expanding popularity and trade of medicinal plants, health, safety and quality of medicinal plant raw materials and processed products have become a major concern for world organizations. Environmental pollutants, including heavy metals, are one of the criteria quality control of medicinal plants and their processed products. Various studies have shown that the amount of heavy metals in medicinal plant depends on the environment growing herbs, plant species, conditions of drying, storage, transportation and processing. Herb growing environmental pollution with heavy metals may influence the biosynthesis of secondary metabolites, can lead to significant changes in the quantity and quality of these metabolites.Pollution of the growth medium of medicinal plants with heavy metals may influence the biosynthesis of secondary metabolites, can lead to significant changes in the quantity and quality of these metabolites. The WHO regulates maximum permissible limit in medicinal plant for cadmium, arsenic and lead 0.3, 1 and 10 mg kg-1, respectively. Some other elements such as copper, zinc, manganese, molybdenum and nickel can be toxic at high levels, but WHO has not to date restrictions apply to these elements. Due to increased use of fertilizers, insecticides and pesticides to improving yield of crops on one hand and increasing urbanization and industrial activities as well as the undisclosed harvest location of medicinal plants in Iran, no national regulations for monitoring and gathering wild plants and the probability of collecting contaminated with heavy metals, accumulation of these elements in medicinal plants may be occurred. Therefore, adequate oversight and quality control of medicinal plants and their processed products can be recommended.
A T; F S
Abstract
Agro-ecological zoning is one of the effective tools for assining land to suitable land use.The study areawith16618ha islocatedin Abyek area inQazvin province. In totally 43 agro- ecoloical zones were distinguished by combining maps of isohyet, isotherm, length of growing periodand Agro-edaphic zones. ...
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Agro-ecological zoning is one of the effective tools for assining land to suitable land use.The study areawith16618ha islocatedin Abyek area inQazvin province. In totally 43 agro- ecoloical zones were distinguished by combining maps of isohyet, isotherm, length of growing periodand Agro-edaphic zones. Based on above information a land suitability was produced for the study area and prediction of production potential was done for each zone. Production potential ranged between 340 to 3000 kg/ha for rainfed wheat and between 455 to 4040 kg/ha for rainfed barley, whilethefarmers yieldis for lowerthanPredicted yields. Soil properties and climate were considered the most limiting factors for crop production in the study area.
Research Paper
a r; s h
Abstract
Total concentrations of mineral elements in soil bear little relation to their availability for plants. The DGT (diffusive gradients in thin-films) technique has been found to be a good predictor of trace metals, micronutrients, phosphorous and potassium bio-availability and uptake. In the DGT technique, ...
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Total concentrations of mineral elements in soil bear little relation to their availability for plants. The DGT (diffusive gradients in thin-films) technique has been found to be a good predictor of trace metals, micronutrients, phosphorous and potassium bio-availability and uptake. In the DGT technique, elements are accumulated on a binding gel after their diffusive transport through a hydrogel. In this review paper, we explore in a more detail why and under which conditions DGT correlates with plant uptake. The theoretical considerations will be illustrated and some of experimental results in relation to metal uptake and toxicity, phosphorus and potassium will be reported. Strong correlations between DGT and plant uptake are predicted if the diffusive transport of the element from soil to the plant roots is rate-limiting for its uptake. If uptake is not limited by diffusive transport, DGT-fluxes and plant uptake may still show correlation. Of course, this will be true in the condition which plant uptake is not saturated. However, competitive cations may affect the plant uptake under these conditions, whereas they have no effect on the DGT flux. Moreover, labile complexes are not expected to contribute to the plant uptake if diffusion is not limited, but they are measured with DGT. Therefore, if plant uptake is not limited by diffusion, interpretation of the observed correlation in terms of the labile species measured by DGT is inappropriate.
Research Paper
H H; M S; M M.A
Abstract
An experiment conducted in 2012 and 2013 in a peach orchard in Shahriar,area showed that offectivness of applaying FeSO4 - organic matter injection, alone or in combination with sulfuric acid, is higher than using Fe-chelates. Determination of leaf greenness with chlorophyll meter indicated that ...
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An experiment conducted in 2012 and 2013 in a peach orchard in Shahriar,area showed that offectivness of applaying FeSO4 - organic matter injection, alone or in combination with sulfuric acid, is higher than using Fe-chelates. Determination of leaf greenness with chlorophyll meter indicated that FeSO4 - organic matter- sulfuric acid injection was as effective as using Fe-chelates in fertigation. Leaf Mn concentration reduced enormously in Fe-chelate treatment. Furtunately reduction of leaf Mn concentration after applying Fe-chelate, which is well described in plant nutrition literature, was not observed in injection treatment. Leaf greenness was determined in the beginning of the second year to evaluate the effectiveness of previous year treatments. It higher values obtained after injection treatments. Yellow leaves were indicative of low efficiency of Fe chelate.The results of this experiment could be an indicates that soil injection of FeSO4 - organic matter- sulfuric acid is a good and inexpensive alternative for Fe chelate in some orchards.
Research Paper
r s; s gh; n gh
Abstract
Soil degradation means lose of soil quality which usually is caused by improper use of land by human. Decline of soil quality includes lose of physical, chemical and biological properties of soil. This study aimed to identify and assess the quality of soil and land, to determine the type of land degradation ...
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Soil degradation means lose of soil quality which usually is caused by improper use of land by human. Decline of soil quality includes lose of physical, chemical and biological properties of soil. This study aimed to identify and assess the quality of soil and land, to determine the type of land degradation and estimates their severity based on completed forms gathered field data and mapping the corresponding in GIS environment. The results showed that the soils of Arab-lu and Ordushahi regions are saline and Jabal-Kandy is also a component of saline and alkaline. Most of surface area is affected by surface erosion. Physical degradation, salinization and erosion of soil nutrients and organic matter occupied the next grades. Salinization especially on the edge of the lake as well as in some parts of the Urmia plain is visible. Recommendations for improving the quality of traditional agricultural practices into modern methods can be effective in reducing soil erosion, land degradation and leaching of nutrients and organic matter of the soil. Type of needed operations for land reclamation is available based on the type, degree and extent of degradation from related maps and can be used by experts.