فهرست مطالب bahman khoshru

Salts accumulation in soil is a major threat to agricultural production and ecosystem sustainability. The cost imposed on agricultural productivity due to salinity and sodicity is very high and is expected to increase in the future with the expansion of salt-affected areas. In the last decade, a great focus has been made on the application of biochar in farming systems with the primary aim of organic carbon sequestration in soil and subsequently reducing greenhouse gases emission to air and also reclaim soils, and increasing soil fertility. But these studies often were in non-saline soils and it is needed to study the biochar effect in salt-affected soils.

Due to the lack of research on the role of biochar in salt-affected soils, this paper first provides an overview of the extent and problems of these soils. Then, the researches on the effect of biochar on soil properties, carbon sequestration, and remeduatuib if sakt-affected soils were reviewed and study and research gaps in this field were investigated.

The application of biochar in the soil causes the sequestration of carbon in the soil and reduces the emission of greenhouse gases into the atmosphere. In the salt-affected soils, biochar, as an organic soil amendment, improves the physical, chemical, and biological properties of the soil, thereby mitigating the effects of salt on soil and plants.

Carbon sequestration and improvement of soil quality are the two reported general benefits of biochar application in soil. The results of researches in this field are different depending on the source and method of biochar preparation, soil properties, and experiment conditions. Therefore, various studies are needed to fully understand the mechanisms of biochar effect on the properties of salt-affected soils and their remediation. It is not possible to provide a practical solution by doing some research, but developing scientific findings in this field can guide future policies.

In recent decades, agricultural production has relied heavily on the use of chemical inputs, which has led to major environmental problems. The use of chemical fertilizers and pesticides has led to the destruction of water and soil resources, reducing the population and diversity of soil microbes, water and air pollution, increasing the resistance of pests and pathogenes to various chemical pesticides, etc. One of the solutions to this problem is to use the principles of sustainable agriculture. Sustainable agriculture is an integrated system based on ecological principles and in this system, plant residues, animal manures, organic and bio-fertilizers are used instead of chemical compounds such as fertilizers and pesticides. In addition to supplying nutrients in the soil, it leads to weed and pest controlling and increases the microbe’s biodiversity in soil. Useful soil microorganisms such as mycorrhizal and endophytic fungi play an important role in the nutrients cycling, especially phosphorus and some other trace elements in ecosystems and plant protection against environmental and agricultural stresses. The fungal hyphae often extend into the portion of the soil that is not penetrated by roots or root hairs, and led to increase the absorption of water and nutrients for the plant. Endophyte fungus Piriformospora indica also has a wide range of host plants by colonizing their roots and stimulates the growth of its host plants and increases their yield. The use of these fungi in nutrient-poor soils increases the growth and yield of agricultural products along with reducing the use of chemical fertilizers and pesticides. Coriander (Coriandrum sativum L.) is an annual herb of the Apiaceae or Umbelliferae families, native to the Mediterranean region that has been cultivated since human antiquity. In addition to its oral application, this plant also has healing properties and is also considered as a medicinal plant. Coriander consumption is recommended in the treatment of various infectious diseases such as typhoid fever and various diseases in general. The shoots of this plant contain essential oils and active ingredients, and decanol is the main components of its essential oil. Whereas global approaches to the production of medicinal plants are aimed at improving the quantity and quality of the active ingredient of medicinal plants, healthy nutrition of these plants through eco-friendly approaches such as the use of biological fertilizers, is the most consistent with the goals of sustainable agriculture and leads to improved quantitative and qualitative yield of these plants. Accordingly, the study of the effect of beneficial soil fungi (mycorrhizal and endophytic) on vegetables such as coriander due to their high consumption by humans seems necessary. Therefore, in this study the effect of inoculation of two species of arbuscular mycorrhizal fungi (Diversispora versiformis ‌ and Rhizophagus irregularis) and one species of endophytic fungus (Piriformospora indica) individually and/or in combinations on the chemical composition and production of coriander essential oil was investigated.

The treatments were included single fungus inoculation (RI: R. irregularis, DV: D. versiformis, PI: P. indica), integrated fungal inoculations (PI+DV, PI+RI, RI+DV and PI+RI+DV), positive control treatment (with urea fertilizer and triple superphosphate, without fungus), and the negative control (no chemical fertilizer, no fungus). The experiment was conducted in a completely randomized design with four replications in greenhouse conditions. Fresh and dry weight of roots and shoots, percentage of root colonization, leaf phenol, antioxidant compounds, carotenoids, total chlorophyll and essential oil were measured in coriander plant.

The results showed that the effect of all three fungal species (mycorrhiza and endophyte) both separately and in combination on the measured parameters was significant (p <0.01). Combined treatment of three fungi (PI + RI + DV) showed the highest yield in fresh and dry weight of shoot part by 8.62% and 17.94%, respectively. In the case of fresh and dry weight of root part, DV treatment had the best performance by 22.66% and 48.04%, respectively. The root colonization increase (91.75%) in PI + RI, phenol (72.5%) in RI + DV, antioxidant componds (11.81%), total chlorophyll (7.81%) and carotenoids (5.87%) in PI, and essential oil yield (107.2%) in PI + DV were recorded. All increases reported above are in comparison with negative control treatment.

According to the results of this study, in order to achieve higher yield in coriander, it is better to use single treatments of mycorrhizal fungi. Also, based on the results of this experiment, to enhance the performance of mycorrhizal fungi to improve the growth and development of coriander, especially to improve the yield of essential oil, it is better to use a combination of mycorrhizal fungi and endophyte. It should be noted that the results of this experiment were obtained in greenhouse conditions and to finally confirm the effectiveness of the fungi used in this experiment, therefore further studies should be performed at the field conditions along with measuring more traits to provide clearer and applied results.

In this study, the effect of potent zinc solubilizing bacteria on zinc supply of single cross cultivar 704 was evaluated.

Isolation of bacteria from rhizospheres of maize, wheat and sunflower was performed in different cities of East Azerbaijan province. The experiment was performed in two phases in vitro and in a greenhouse in a completely randomized statistical design with three replications.

A total of 20 bacterial isolates were obtained from the rhizosphere of the studied plants. In qualitative evaluation, the results showed that ZP13 isolates in zinc phosphate source, ZO11 in zinc oxide source and ZC10 in zinc carbonate source with HD / CD ratio with 1.74, 1.68 and 1.61, respectively, had the highest solubility. In quantitative evaluation of zinc solubility, ZP13 isolate (24.64 mg / L), ZC10 isolate in zinc carbonate (19.48 mg / L) and ZO11 isolate in zinc oxide (26.54 mg / L) had the highest solubility. The two isolates ZO11 and ZO14 in comparison with the negative control treatment led to an increase in zinc uptake of 179.7 and 62.37% in the root and 155.1 and 110.6% in the shoot part of maize, respectively. Identification of isolates ZO11 and ZO14 showed that they belong to Acinetobacter calcoaceticus and Agromyces italicus, respectively.

According to the results of this experiment, the potential of rhizobacteria of different plants can be used to provide the zinc required by plants as a healthy and eco-friendly solution.

The products from medicinal plants are directly used for human consumption or used in the formulation of drugs. Therefore, in addition to quantity, their quality is also considered. Water deficit stresses could affect the quality and quantity of the active substance in these plants. It has been reported that the use of Piriformospora indica as an endophytic fungus in some plants reduces the harmful effects of water deficit stress. Probably this fungus will have direct and indirect roles in the production of plant metabolites likely by reducing the adverse effects of water deficit stress. Accordingly, this research was conducted in a completely randomized design with factorial arrangement with two factors including two levels of P. indica (inoculated and non-inoculated) and soil moisture with three levels of 80-90 %FC (W0, 60-70 %FC (W1) and 40-50 %FC (W2) with four replications. The results showed that inoculation with P. indica increased the measured characteristics of anise compared to the non-fungal treatment. Severe water stress (W2) lead to an increase in shoot dry weight (58.93%), root dry weight (56.25%), seed yield (392.06%), essential oil yield (340.08%), percentage of essential oil (154.55%) and the amount of anethole essential oil (236.85%) in inoculated compared to the non-inoculated plants. In fungal treatment, the essential oil yield and percentage and the amount of anethole had the highest value at the level of moderate stress (W1). In this study, it was found that P. indica increases the medicinal quality of anise essential oil by increasing its anethole amount.

The use of biofertilizers is very effective in soil fertility, food safety of consumers and environmental health. In this study, arbuscular mycorrhizal fungi were produced with two types of culture media in greenhouses.

this experiment, seven species of mycorrhizal fungi were propagated in two types of pot substrates in the presence of corn plant in greenhouse conditions with a growth period of four months. Fungal species were Rhizophagus intraradices, Glomus versiforme, Rhizophagus irregularis, Scutellospora calospora, Claroideoglomus etunicatum and Funneliformis mosseae. Two types of pot substrates including A substrate: (cocopeat, vermiculite with a volume ratio of 1:1 and Humic acid with a concentration of 250 mg/L) and B substrate: cocopeat, vermiculite and compost (With a volume ratio of 1: 1: 0.4) were used for plant culture.

The results showed that the percentage of root colonization had no significant difference between the substrates type, but the simple effects of the fungi (P <0.01) and the interactions of the fungi × substrate (P <0.05) were significant. In A substrate, Rhizophagus irregularis (72.87%) and in B substrate Rhizophagus irregularis-Sweden (67.12%) and Glomus versiforme-Tabriz (67.85%) showed the highest percentage of root colonization. The fungi Rhizophagus irregularis and Glomus versiforme were tested for inoculum potential by MPN method and the number of their propagules were 30 and 22.5 in 50 ml of substrate, respectively.

Based on the test results, the use of organic compost is recommended compared to humic acid in terms of economics and easy accessibility.

 Using the potential of soil microbes such as mycorrhizal fungi in the form of biofertilizers is an environmental friendly way to help reduce the use of chemical inputs and reduce the damage to the environment and humans. In this study, the effect of inoculation of coriander with two species of mycorrhizal fungi (Diversispora versiformis and Rhizophagus irregularis) and one species of mycorrhiza-like fungus (Piriformospora indica) on the yield and phosphorus uptake was investigated in a pot culture experiment.

 The results showed that the application of all three species of fungi were significant in terms of the effect on growth indices (shoot and root dry weight) and phosphorus concentration compared to the control treatment (p <0.01). Compared to the negative control, the enhancement of shoot dry weight in PC was 36.13%. Accordingly, the root dry weight in R. irregularis, PC and D. versiformis treatments (48.04%, 45.65% and 42.94%, respectively), the chlorophyll index in P. indica (32.18%), the root colonization in P. indica + R. irregularis (91.75%), the shoot phosphorus concentration in P. indica (34.50%) and root phosphorus concentration in P. indica + R. irregularis (25.88%) were higher compared to the negative control treatment.

 According to the results of this study, mycorrhizal fungi can be used in vegetable cultivation to reduce the use of phosphate fertilizers to increase plant yield.

Nutritional status of medicinal plants is important due to their direct involvement in human dietary. Also, water deficit stress may adversely affect nutrient uptake and biomass production of these plants. There are evidences indicating that endophytic fungusPiriformospora indica improves nutrients uptake and mitigates water deficit stress in plants. In this study, a pot culture experiment was conducted in a completely randomized design with factorial arrangement with two factors including two levels of P. indica (inoculated and non-inoculated) and soil moisture with three levels of 0.8-0.9 FC (W0), 0.6-0.7 FC (W1) and 0.4-0.5 FC (W2) with four replications. The results showed that the interaction effect of water deficit × fungus on all morphological characteristics except plant height was significant (P <0.05). In severe water deficit stress (W2), fungal inoculation leads to increase in dry weight of shoot (22.4%) and root (8.4%), chlorophyll index (4.9%), chlorophyll fluorescence (5.5%), shoot (61.3%) and root (65.6%) P concentration, shoot (22.6%) and root (24.6%) K concentration, root colonization (100%) and seed yield (47.1%) compared to the un-inocultaed controls. Although the highest values of above mentioned traits were recorded at the highest moisture level (W0) in the presence of P. indica.

One of the most important microbial fertilizers is phosphate microbial fertilizers, it can be prepared in powder or granular form, which, after mixing the constituents, should be used for gentle heating (40-50 degrees Celsius) to dry the fertilizer, such conditions will eliminate the bacteria that are added to the carrier. The use of temperature resistant phosphate solubilizing bacteria in granular phosphate fertilizers is one of the strategies to overcome the limitations of these fertilizers production.

In this research, the efficacy and effectiveness of phosphatic microbial fertilizers prepared from two temperature resistant phosphate solubilizing bacteria (RPS9 and RPS7) and a non-temperature resistant bacterium (PS4) in the basal formulation of rock phosphate (45 g), sulfur (15 g) and bagasse (30 g) was evaluated on corn S.C.704 cultivar. Experiments were conducted in a completely randomized design with regard to control treatment (without microbial fertilizer and chemical fertilizer), triple super phosphate fertilizer treatments at 50% and 100% fertilizer recommendation, with bacterial treatments (PS4, RPS7 and RPS9) in three replications Done. The irrigation of the pots was carried out through weighing at 0.8FC.

The results of greenhouse experiments showed that the application of phosphatic microbial fertilizers in corn, on fresh and dry weight of the whole plant, absorption of phosphorus, potassium, iron and zinc in the root and shoot part had a significant effect. The PS4 microbial fertilizer application had the highest amount of phosphorus absorption and in this regard was treated with chemical treatments SPT (100% and 50%) in same group and increased the rate of absorption of phosphorus by 25.07% compared to negative control and 23.49 % Compared to control without carrier (No Carrier). In potassium parameters of the plant were also treated with SPT fertilizer (100%) and PS4 microbial treatment led to highest potassium uptake with average of 585.685 and 511. 343 (mg / plant), respectively. Microbial treatments of PS4 and RPS9 in the supply of phosphorus and potassium of the corn plant were well treated with triple super phosphate. RPS9 of microbial fertilizer in the Fe parameter and RPS7 in Zn parameter had the highest performance.

Inoculation of microbial fertilizers containing plant growth promoting bacteria has led to the colonization of these bacteria in the plant's rhizosphere, and we have seen the incremental effects of measured parameters. PS4 bacterial treatment was similar to triple super phosphate treatment (100%) and RPS9 treatment was similar to triple superphosphate (50%). RPS7 has lower performance. Among the two newly-released temperature resistant isolates, both of which are Pantoea agglomerans, it seems rational to use RPS9 for this purpose.

Application of chemical and organic carrier and its integration with useful microorganisms including phosphate solubilizing bacteria (PSB) has facilitatedproduction of phosphate microbial fertilizers (PMFs), which are used in granular or powder form. One of the major limitation of thesebiofertilizers is decline or loss of PSB viable cell in the granule preparation process. Accordingly, in this study, isolation of temperature resistant phosphate solubilizing bacteria was performed and temperature tolerance and ability to dissolve phosphate from rock phosphate (RP) and tricalcium phosphate (TCP) sources were evaluated.
Firstly, each soil samples incubated for 16 hours at 55 °C, then dilution series were prepared and 100 μl of four final dilutions (10-6, 10-7, 10-8, and 10-9) were used to spread on Sperber solid medium. After spreading the microbial suspensions from the dilutions in the Sperber solid culture medium and the appearance of colonies, screening based on the resistance to soil temperature treatment and, subsequently, the ability to grow in a solid Sperber solid medium and dissolution of low solubility phosphate (formation of transparent halo), was done to isolate PSB. In order toprepare PMF, each of screened PSB were cultured in NB, andthen 1 ml of overnight culture wasmixed with 9 ml sterile distilled water and added to the basal formulation of rock phosphate (45 g), bagasse (30 g) and sulfur (15 g) with initial temperature of20°C.Temperature treatments (55 °C for 16 hours) of bacteria were performed in three steps: a) on sampled soils, b) pure-culture of bacteria and c) bacteria added to the carrier. Microbial population in provided microbial fertilizer was countedin two ways a) half of the microbial fertilizer was kept at normal temperature by maintaining the initial conditions, b) another half after the temperature applied (55 ° C for 16 hours). The semi-quantitative and quantitative test of insoluble inorganic phosphate solubility was performed by isolates in solid and liquid Sperber medium. The 16S rRNA molecular method was used to identify the isolated bacteria by general primers 27F and 1492R.
Five bacteria (RPS4, RPS6, RPS7, RPS8, RPS9) out of nine isolated bacteria were able to solubilize mineral phosphate (TCP and RP) but only two isolates (RPS7 and RPS9) were resistant to temperature (55 °C for 16 h). In tricalcium phosphate medium, the RPS9 and RPS7 bacteria had a high ability to solubilize insoluble inorganic phosphate with average of 2.60 and 2.27 for a ratio of (HD / CD) after 12 days, respectively. There was no halo in Sperber medium containing rock phosphate. The amount of solution in the quantitative methods was also obtained to be 563.8 and 324.1 mg / l for RPS9 and RPS7 bacteria, respectively. The prepared microbial fertilizer was counted in two ways (a): half of the sample fertilizer was kept at normal temperature by maintaining the initial conditions; (b):after the maintaining temperature at 55 °C for 16 hours, the population of other half was determined. During counting the initial microbial population (zero time) at normal temperature, all bacteria used in microbial carrier had an acceptable population. During examining the populationsof microbial in the initial carrier, RPS4, RPS6, RPS7, RPS8 and RPS9 bacteria were 3.6, 3.5, 3.6, 3.5, 3.6 and 3.5 (×106 CFU/g), respectively. After 4 months the populations were 4.6, 6.3, 9.6, 7.4 and 8.6 (×105) and in the 6th month, the populations were 3.9, 3.8, 12.3, 4. 7 and 9.2 (×104) seeming to be favorable for the tested bacteria. It seems that this survival time for the tested bacteria is desirable. During countingactive population of temperature treated microbial fertilizers, the initial population of the microbial carrier (at zero time) decreased 10 times with respect to the non-treated carrier. Active population ofRPS9 and RPS7 (temperature-resistant treatments) in the zero time was 4.5 and 4.3 (×105), respectively. Although the RPS9 and RPS7 microbial populations were able to survive in non- temperature treatments for 6 months, it was observed that in the treatment, this viability practically reduced to 4 months. Molecular identification of the isolates RPS7 and RPS9 revealed that they belonged to Pantoeaagglomerans.
According to the findings of this research, using phosphate solubilizing bacteria and temperature resistant Pantoeaagglomerans RPS9, recently isolated and identified, can be considered toindustrially produce granular microbial fertilizers. It is worth mentioning thatfurther studies are required to be carried out on the effectiveness of this formulation with these bacteria infield scale.