جستجوی مقالات مرتبط با کلیدواژه « ازتوباکتر » در نشریات گروه « آب و خاک »

The factorial experiment based on a randomized complete block design was conducted with three replications at the research greenhouse of Tabriz University in 2017. The experimental factors include three levels of salinity stress (non-saline, salinity 3 and 6 dS/m) from the source of sodium chloride, foliar spraying in three levels without hormonal and nutritional foliar spraying, foliar spraying of 2 mM silicon and foliar spraying of 1mM salicylic acid, and the third factor, bacterial inoculation in four levels included: no inoculation, inoculation with Azosprilium, inoculation with Azotobacter and combined inoculation of two bacteria. The results of this research showed that the salt stress reduced the growth and yield of garlic. Spraying of salicylic acid and silicon and inoculation with bacteria improved potassium absorption, plant height, and leaf surface area, number of leaves per plant, yield components, biomass, and yield of garlic. The treatments significantly reduced the sodium concentration in both roots and leaves. The positive effects of the proposed treatments not only improved plant growth and performance under salinity stress conditions but also under non-saline conditions. Among the studied treatments, salicylic acid and silicon foliar applications along with the combined use of Azospirillium and Azotobacter showed more favorable effects on the growth and productivity of garlic than the other treatments. Finally, it was suggested to use growth-promoting bacteria in combination with salicylic acid and silicon solution spraying to mitigate the effects of salinity stress in garlic plants.

Barley (Hordeum vulgare L.) is one of the crops that has a high nutritional value and can be used as animal feed and cover crop to increase soil fertility, as well as has various applications in the food industry. One of the cheap and accessible methods for farmers to increase the efficiency of food elements is to use of efficient crop cultivars. Based on the principles of sustainable agriculture, one of the methods to improve the nutrition of crops is to use of biological fertilizers. Considering the importance of barley cultivation in Lorestan province, this study was conducted in order to investigate the effect of biological fertilizer and compare common cultivars in this region.

In order to investigate the growth response of some barley cultivars to biofertilizer, an experiment was conducted in the form of split plots in the form of a randomized complete block design with three replications in 2014-2016. The main plot includes three varieties of barley including Mahor (M), Izeh (I) and Khorram (K). The sub-plot of four types of biofertilizer treatments included control (without biofertilizer), Azotobacter (A), mycorrhizal (M) and Azotobacter + mycorrhizal (AM). Barley seeds were inoculated with biofertilizers according to their instructions before planting. The seeds were poured on nylon in the shade, and one package of biological fertilizer per hectare was dissolved in an appropriate volume of chlorine-free water, and after filtering the fertilizer solution with a thin cloth, it was sprayed on the seeds with a sprayer and mixed well. All of them should be evenly coated with fertilizer. At the time of plant harvesting, some growth characteristics including seed yield, straw yield, number of seeds per spike, number of spikes per square meter and weight of 1000 seeds per plot were measured.

The result of analysis of variance showed that cultivar has a significant effect on grain yield, straw yield, number of seeds per spike, number of spikes per square meter, and thousand grain weight. The result of the average comparison showed that the highest grain yield, straw yield, number of seeds per cluster, number of clusters per square meter and weight of 1000 seeds are related to M-AM treatment. As a result, Mahor variety had the highest grain yield compared to other two varieties. Among the fertilizers used, Azotobacter + Mycorrhiza was the most effective. Therefore, the interaction effect of these two treatments has the greatest effect on grain yield (4931 kg/ha), straw yield (8797 kg/ha), number of seeds per spike (16), number of spikes per square meter (546) and weight of 1000 seeds (17.8 grams).

results showed that in order to achieve the highest seed yield, it is suggested to cultivate Mahor cultivar along with Azotobacter and Mycorrhiza treatment in the region. It is necessary to evaluate other cultivars and other biofertilizers in the region.

In order to investigate the effect of growth-promoting bacteria inoculation on soil characteristics, nutrients uptake and growth of bell pepper, a randomized complete block design with five species of growth-promoting bacteria (Bacillus subtilis, Azospirillum lipoferum, Azotobacter chroococcum, Enterobacter cloacae and Pseudomonas putida) with three repetitions was carried out in Isfahan Wheat Field greenhouse in 2021. The chemical and biological properties of the soil, NPK uptake, and the growth and yield characteristics were investigated. The results showed that the addition of growth-promoting bacteria effects on some soil characteristics and bell pepper growth. The treatments showed a significant difference in terms of total nitrogen, phosphorus and potassium available in soil, respiration and rhizospheric microbial population, NK uptake, yield and fruit number (p≤0.01). The best soil nitrogen content (0.44%), nitrogen uptake (28.8 g.m-2) and shoot dry weight (0.565 g.m-2) were observed in Azotobacter chroococcum treatment. The highest rhizospheric microbial population (7.6×106 cfu.g-1) and R/S ratio was 47.9 in Enterobacter cloacae treatment. Fresh weight and dry weight of plant shoot were higher in Azospirillum lipoferum treatment, which was not significantly different from Azotobacter chroococcum and Enterobacter cloacae treatments. In the treatment of Enterobacter cloacae, the yield (18.8 kg.m-2) and the fruits number (65.8/m2) were higher. The application of Enterobacter cloacae, Azotobacter chroococcum and Azospirillum lipoferum bacteria was higher effect on the growth indicators of pepper, which can be recommended for the use of these bacteria as biofertilizers in bell pepper cultivation.

Recently, growth-promoting bacteria have been proposed as complementary and increased efficiency of chemical fertilizers in order to increase soil fertility in crop production in sustainable agriculture. In order to study the effect and efficacy of plant growth promoting bacteria and different rates of phosphorous fertilizer on growth parameters, nutrient availability and wheat yield (Mahdavi variety), a field experiment was conducted as factorial based on completely randomized block design in three replications. Experimental factors include five rates of phosphorous (0, 25, 50, 75, and 100 kg/ha P) and soil inoculation with bacteria at four levels including no-inoculation (Control, I0), inoculation with Azotobacter (I1), inoculation with Pseudomonas (I2) and inoculation with Azotobacter and Pseudomonas (I3). Results of variance analysis showed a significant difference on the effect of seed inoculation and phosphorous levels on plant height, root length and germination percent of wheat seeds. In this research, the treatment of 100 percent P-requirement in the soil inoculated with Azotobacter and Pseudomonas showed a greatest effect on increasing soil phosphorous (27%), growth (28%), yield (27%), yield components (31% grain yiehd) and grain phosphorous (27%) of autumn wheat. Increase in plant dry weight by rhizobacteria is due to increase in nutrients uptake and subsequently better plant growth which could result in higher harvesting index.

Today, the use of chemical fertilizers to increase agricultural production has created many environmental problems. In addition, environmental stresses are one of the most important factors reducing crop yield and production. Given the importance of rice plants in ensuring food security nationally and globally and increasing the price of chemical fertilizers, it is necessary to find eco-friendly routes for sustainable agriculture. The use of biofertilizers is the most worthy way to reduce the use of chemical fertilizers and improve plant resistance in rice fields. Azotobacter has been used as a biofertilizer for over a century and has been well studied on a laboratory and field scale. Azotobacter have also been reported as nitrogen-fixing bacteria in the rhizosphere and roots (endophytically) of rice. In this study, the effect of Azotobacter biofertilizer as a plant growth-promoting rhizobacteria, on rice and the mechanisms of this effect were investigated. The results showed that this bacterium produces phytohormones and stimulants of plant growth and fix atmospheric nitrogen in the rhizosphere and as an endophyte in rice. In addition to nitrogen fixation, this bacterium increases plant growth indices, nutrient uptake, and grain yield of rice by dissolving insoluble phosphates, producing indole acetic acid, hydrogen cyanide, siderophore. Also, the use of Azotobacter inoculant in acute salinity conditions increased the concentration of proline, malondialdehyde, ACC-deaminase enzyme, and some hormones in the plant, which increased the resistance of rice to this stress. Considering the positive effect of using Azotobacter inoculant as a biofertilizer on rice plants and the effect of this bacterium on reducing the consumption of nitrogen fertilizers, preparation of biofertilizers containing native bacteria of Azotobacter and their application in rice fields is recommended.

One of the main pillars of sustainable agriculture is the use of biofertilizers in agro-ecosystems to modify and reduce the use of chemical inputs. This study was carried out to investigate the effect of growth promoting bacteria on soil chemical properties in a clover- rice cropping system using a factorial experiment with randomized complete blocks having three replications at the research site of Rice Research Institute of Iran, during 2015- 17. Experimental factors for clover included four levels of inoculation with symbiotic bacteria Rhizobium trifolii and four levels of inoculation with non- symbiotic plant growth promoting bacteria. The results showed that clover cultivation led to a significant increase in the percentage of soil organic carbon (1.79%) and nitrogen (0.216%). The Application of non-symbiotic bacteria in clover cultivation caused a significant increase in soil phosphorus in rice cultivation. The highest amount of soil phosphorus was obtained in treatments of Pseudomonas (12.38%) and Azotobacter+ Pseudomonas (11.8 ppm) in rice cultivation. Also, rice cultivation significant reduced available potassium in the second year (121.1 mg/kg) compared to the first year (128.3 mg/kg). According to the overall results of this study, the use of growth promoting bacteria while maintaining and improving the chemical properties of the soil increased the average rice yield in the second year (3250.3 kg/ha).

A field experiment was carried out in order to investigate the effect of several types of nitrogen biofertilizer on yield and yield components of two wheat cultivars (Chamran and Shiroudi) as split plots based on randomized complete block design with three replications in Darab city. Wheat cultivars (spring type Chamran and Shiroudi) were considered as main plots and biological fertilizers (General Nitragin (A1) – Nitragin special Cereal (A2) –Nitrokara (A3) –Nitroxin (A4) – Nitrogy (A5) – Nitrogen biofarm (A6) – 100% pure Nitrogen (A7= 400 kg ha-1 as urea) – without Nitrogen application (A8)) as subplots. The measured indices included plant height, number of spikes per square meter, number of seeds per spike, 1000 grain weight and yield per unit area. According to the results, there was a significant difference between wheat cultivars (P ≤0.05) and fertilizers (P ≤ 0.01).  The treatment A4 (nitroxin + 60% pure nitrogen from urea source) obtained the highest values for the measured indices. The A2, A1, A3, A6 and A5 treatments were arranged in the next step, respectively. A7 treatment, which was exclusively urea, was arranged in the next step. Generally, the biofertilizers applied in this study containing nitrogen fixation bacteria (NFB) from Azotobacter and Azospirilum genuse, if accompanied with nitrogen fertilizer like Urea, could be a suitable and safe alternative for supplying a part of nitrogen chemical Fertilizers.

There are different methods for evaluation of the biological nitrogen fixation, which they are mainly included acetylene reduction assay, labeled nitrogen and nitrogen difference methods. Accuracy and sensitivity of these methods are different, but applying of some of these methods isn’t possible in all laboratories, so it cause the use of less accurate methods for evaluation of the nitrogen fixing content. Therefore, this article was aimed to investigate the content of nitrogen fixation (NF) of some bacteria isolates including Azotobacter using the Kjeldahl method. A total of 22 bacteria isolates were used and evaluated. The isolates were cultured in solid and liquid LG media and the content of the nitrogen fixation was measured in solid and pellet of liquid culture. According to the results of digestion, distillation and titration (Kjeldahl) of the cultured sample in the solid medium, the maximum nitrogen-fixation content 261.10 and 258.64 µg/g were found in 14SP- Ш and 14SP2-1, respectively. The highest nitrogen-fixation content in liquid culture medium was obtained in 14SP-I (80 µg/ml). The results of liquid and solid culture media indicated that the maximum nitrogen in14SP-I and 14SP2-1 isolates belonged to the Azotobacter chroococcum, Pseudomonas 35SP-2, and Achromobacter 14SP- Ш. The results of NF in both solid and liquid cultures showed a good correlation (r=0.69**). It seems that the method can be used for screening the efficient nitrogen fixing bacteria, although this is not so a precise method. 14SP-Ι, 14SP-Ш, 14SP2-1, 35SP-2 and 44SP-2 strains can be suggested among the isolates for the greenhouse and farm experiments.

This review attempts to reflect the history and importance of soil biology and the biological properties of soils in Iran. This paper also aims to extensively evaluate the biological characteristics of soil with respect to some features of soils, climate and vegetation. Then, the biological properties of the dominant soils in Iran are mentioned. Research findings about the possibility of using the soil biological potentials in agriculture, especially production and commercialization of technological knowledge of bio-fertilizers are discussed. Furthermore, the list and characteristics of useful soil microorganisms that exist in the country in a form of “Microbial Bank” are mentioned. Finally, the potentials and capacities of production and consumption of bio-fertilizers, the priorities and challenges encountered in the field of soil biology in the country are discussed.

Soil fertility management through use of organic and biological fertilizers is a crucial component of sustainable agriculture. A greenhouse experiment was carried out to investigate the effect of vermicompost and plant growth promoting rhizobacteria (PGPR) on the growth and nutrient uptake of sesame seedlings. This experiment was conducted in factorial based on completely randomized design with four replications. Experiment factors included four levels of (zero (V0), 1 (V1), 2 (V2) and 4 percent (V3)) and five bacterial levels (without bacteria (B0), inoculation with an isolate from fluorescent pseudomonads group, having ability to dissolve inorganic phosphate (B1), Azospirillum sp. (B2) and Azotobacter sp. (B3) with ability to fix nitrogen, and a mixture of three bacteria (B4). The results showed that the main effects of vermicompost and PGPR significantly enhanced the leaf area, stem diameter and chlorophyll index in comparision to the control. Also, the combined application of vermicompost and PGPR significantly increased the shoot dry weight, plant height, number of leaves and nitrogen, phosphorus, iron, manganese, zinc and copper uptake in sesame seedling (P

Over the past few decades, effort to increase production per unit area and excessive and unbalanced application of fertilizers has led to environmental destruction. Application of bio-fertilizers, without adverse impacts on environments and providing some plant nutritional requirements, has improved some physical, chemical and biological properties of soil. Azotobacter is one of the soil microorganisms which is able to simulate the growth of crops. This bacteria affects plant growth parameter directly or indirectly. This study was conducted for 43 strains of Azotobacter, and maximum molecular biological nitrogen fixation acetylene reduction (ARA) to isolate 3 times with 276 nmol h pipe, most can be little solubility of phosphorus in the medium Asprbr colorimetric method using spectrophotometer device to isolate No. 25 is equal to 232 mg l, Slightly soluble potassium minerals Aleksandrov's most potent medium of film photometer device to isolate No. 23 with 47 mg l, most potent hormone auxin in LB tryptophan medium with for colorimetric spectrophotometer method for isolate number 37 is equal to 98 mg l and More than half the diameter of the colony is a measure of the ability to produce siderophore on the CAS-Agar-related isolates 4, 9, 16, 18, 31, 37, 38, 40, 41 and 43 respectively. The ability to produce hydrogen cyanide was measured among all isolates, only 4 isolates were able to isolate the maximum amount of hydrogen cyanide is 43.

In order to evaluate the effect of Azotobacter chroococcum different strains on morphophysiologic characteristics, seed yield and yield components of fall rapeseed (Brassica napus L.), an experiment was conducted in Rasht. The experimental design was completely randomized block, with three replication. Investigated treatments were including seed inoculation with Azotobacter different strains (6, 9, 11, 12, 13, 14, 15, 16, 19, 21, 23, 25, 28, 35 and 38) and chemical fertilizer application (full Urea fertilizer application) and without seed inoculation conditions (control). Results showed that Azotobacter strains significantly affected on all traits except plant height, weight of 1000 seeds, stem diameter and number of secondary branches. The most distance of the first secondary branch until ground obtained by A. chroococcum strain 35, as A. chroococcum strain 14 caused the highest of silique length, dry weight, seed yield and number of seeds per silique. The most leaf erea, dry weight, seed yield and yield components caused by A. chroococcum strain 12. Generally, A. chroococcum strain 12, A. chroococcum strain 14 and A. chroococcum strain 9 had the more positive effect on traits compared with other strains. Results of this experiment showed the use of A. chroococcum increase quantitative and qualitative characteristics of canola in relation to full Urea fertilizer application and the savings in fertilizer consumption and reduce environmental degradation, therefore can be used as supplementary of chemical fertilizer.

Plants are the most sources for cadmium enters to human food and this element in food regime may be a serious threat to human health. Thus, the effect of Azotobacter inoculum (Azotobacter chroococcum), mycorrhiza fungi (Glomus intraradaices), zinc sulphate and urea on cadmium Convertation and growth parameters of fenugreek medicinal plant (Trigonella foenum gracum L.) in cadmium polluted soils were evaluated. This experiment conducted in randomized complete block design with three replications at the research greenhouse of Shahrekord University. Eight fertilizer treatments included control (without fertilizer), urea, urea+ zinc sulfate, urea+ Azotobacter, urea+ mycorrhiza, urea + zinc sulfate + Azotobacter, urea + zinc sulfate + mycorrhiza, urea + zinc sulfate + mycorrhiza + Azotobacter. The results indicated that the highest of plant height, leaf fresh weight and shoot fresh weight of the aboveground of fenugreek were obtained in urea+ Azotobacter but it didn’t have a significant difference with that of the urea + zinc sulfate + mycorrhiza. Also, the lowest cadmium concentration (0.09 mg/kg) was produced in urea+ Azotobacter and urea + zinc sulfate + mycorrhiza (P≤0.05). Appliction two biofertilizers sources plus zinc sulfate in compared to chemical fertilizer treatments had appropriate vegetative growth and fairly cadmium concentration. In conclusion, Azotobacter application for fenugreek production in addition to increase yield and can be effective in preventing of cadmium transmission in the human food regime as well as.

Under arid and semi-arid conditions, water deficiency may limit the use of nitrogen by plant and lead to a decline in crop production and water use efficiency. Therefore, in order to study the effect of drought stress and various fertilizers on different aspects of water use efficiency and biomass of isabgol, a factorial experiment was conducted in a randomized complete blocks design with four replications under microcosm conditions. Treatments included two levels of drought stress (non-stress and with stress) as the first factor, two levels of mycorrhizae (inoculated with G. intraradices and non-inoculated) as the second factor and three fertilizer types (separate application of Azotobacter chrococcum, application of 40 kg N/ha as urea fertilizer, and combined application of azotobacter plus 20 kg N/ha as urea) as the third factor. The results indicated that drought stress reduced the root and shoot biomass on average by 31% and 28%, respectively. But, mycorrhizae caused the increase of root and shoot biomass on average by 65% and 24.7 %, respectively. Water use efficiency increased for the aboveground biomass and total biomass production in drought stress plus mycorrhizae and 40 kg N/ha as urea. However, water use efficiency for seed and mucilage production was only affected by drought stress and mycorrhizae. In conclusion, results showed that water use efficiency for seed production was only increased by mycorrhizal inoculation under drought stress. However, water use efficiency for mucilage production not only increased in drought stress conditions, but also it increased more in mycorrhizal inoculation treatment under drought stress conditions.

In this study, effects of bio-fertilizers on yield potential and agronomic characters of safflower (Carthamus tinctorius L.) cultivars under different irrigation regimes were evaluated. Experimental design was RCBD with split plot factorial arrangement and 3 replication that was done on growing season of 2010-2011 at Kerman, (Iran). Different irrigation intervals included 5 days, 10 days and 15 days was applied in main plot and two levels of bio-fertilizers control and Azotobacter sp. and Azosprillum sp.+ phosphate bio-fertilizer as well as three cultivars (Goldasht, Sina and Mex. 22-191 line) were placed as sub plot with factorial arrangement and different agronomic traits were measured. Results showed that all of the traits significantly affected by irrigation regimes except harvest index. Delay in irrigation from 5 to 15 days reduced 33.11% of the seed yield, also all traits except number of seed per head and harvest index significantly affected by application of bio-fertilizers. There were significant differences in all of the measured traits except harvest index among the cultivars that represented variation among them while Irrigation×cultivar intraction was no significant that represented same responses of cultivars to different irrigation regimes. Irrigation×fertilizer×cultivar interaction effects were significant for number of head per plant and 1000-seed weight and the interaction effect of fertilizer×cultivar was significant for biological and seed yield. Biological and seed yield increased with application of bio-fertilizers compared to the control. According to the obtained results the highest seed yield was obtained from Mex. 22-191 line, in application of bio-fertilizer conditions.

Due to the indiscriminate use of nitrogen fertilizers, pollution caused by the use of fertilizers and high production costs, the present study examined the effects of plant growth promoting biofertilizers and nitrogen fertilizer on increasing the quality and quantity of wheat. The experiment was conducted in two-factor factorial design in three replications; (T0: as control treatment without biofertilizer T1: biofertilizer containing Azotobacter chroococcum and Azospirillum brasilense with population density of 106 cfu ml-1 of inoculum, T2: bio-fertilizer containing Azotobacter chroococcum and Azospirillum brasilense with population density of 108 cfu ml-1 of inoculum, T3: the bio-fertilizer containing Azotobacter chroococcum, Azospirillum brasilense, Pseudomonas putida and Baillus subtilis with population density of 108 cfu ml-1 of inoculum) and nitrogen fertilizer (N0: Control, N1:25, N2:50, N3:75, N4:100 kg N ha-1) in a completely randomized design. The results showed that the main effect of bio-fertilizer was related to treatment T3 which resulted respectively in 13, 20.4, 8, 19.7 and 8%increase in the 1000-grain weight, plant height, grain nitrogen content, grain yield and grain protein content in comparison to the control. In the case of main effect of chemical fertilizer levels on the mentioned parameters, the treatments 75 and 100 kg N ha-1 were the best treatments and they didnt show a significant difference (P>0.05). Regarding interactions of the treatment T3 with N3 had the highest amount and resulted respectively in 50, 51, 57.3, 81.3 and 50.5% increase in the 1000-grain weight, plant height, grain nitrogen content, grain yield and grain protein content.

In this research the effect of three Azotobacter inoculums in solid and liquid carrier were evaluated on growth and yield of rainfed wheat in Maragheh (Iran). The project was randomized complete block design with four replications which included control, solid A and B inoculants, liquid inoculum, farmyard manure, nitrogen fertilizer, a mixture of inoculums and manure. The results showed that the inoculants had not significant effects on growth indices, but inoculants + manure especially in liquid inoculums had the highest effect on growth and yield of wheat. Inoculation increased by 36.2% the seed yield, 37.8% the yield of shoot + root, 73% the N-uptake, 79% the P-uptake, 45% the Zn uptake, 27.6% the protein of seed over control. Manure without inoculum increased by 13.7% in seed yield, 42.5% in N-uptake, 57.5% in P-uptake and 25.8% in seed protein over control. The solid inoculants (A and B) + manure had significant effects on Zinc uptake. The seed protein content increased by 22.1 % due to the solid B inoculum.

Azotobacter is an important bacteria in crop rhizosphere. This research aimed the isolation of local Azotobacter under cultivation of soybean plant in Golestan province and their potential growth promoting-ability. After identification of 30 isolates their ability to molecular nitrogen fixation were tested with Acetylene to Ethylene reduction method. Their ability in auxin production and solubilizing the mineral P were tested with colorimetric method and sidrephore production potential was tested with Cas-agar medium. The maximum nitrogen fixation was in Az26 (428.23 nm.vial.h-1 ethylene) and minimum in Az27 (21.39 nm.vial.h-1 ethylene). Auxin production was highest in Az4 isolate (27.3 mg/l) and lowest in Az20 isolate (0.0157 mg/l). Also maximum sidrephore production was in Az9 and minimum in Az18 observed with diameter halo on colony of 6.36 and 2.24 in 72 hours respectively.

Soil beneficial microorganisms such as plant growth promoting rhizobacteria (PGPR) are able to enhance plant growth. The research was conducted using a randomized complete block design as split plot factorial with three factors (nutrient management, Azospirillum and Azotobacter strains). In this experiment the effect of Azospirillum and Azotobacter inoculation on yield and yield components of maize was evaluated in a field trial. Azotobacter levels were A0: no inoculation, A1: Azotobacter sp. Strain5، A2: Azotobacter chroococcum DSM2286 and Azospirillum levels were Z0: no inoculation, Z1: Azospirillum sp. Strain21, Z2: Azospirillum lipoferum DSM 1691, Z3: Azospirillum brasilense DSM1690. Results of this study showed inoculation with Azotobacter had significant effect on grain yield, stem and total dry weight, plant height and leaf area as well as 100 seed weight. The same results were obtained with Azospirillum inoculation. The interaction between two bacteria on grain yield, 100 seed weight, number of seed per ear, ear diameter, stem, leaf and total dry weight, plant height, leaf area and nitrogen uptake in seed were significant.