Hadi Radnezhad; behzad Behtari; Ali Asghar naghipour Borj; Shole Haj Agfha Memar
Volume 23, Issue 4 , March 2017, , Pages 760-771
Abstract
Plant growth-promoting rhizobacteria are a subset of bacteria, accumulating on the root and rhizosphere. One of the seed priming methods is the use of microorganisms in seed inoculation, known as biopriming. The use of these microorganisms in seed inoculation leads to increased plant performance, especially ...
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Plant growth-promoting rhizobacteria are a subset of bacteria, accumulating on the root and rhizosphere. One of the seed priming methods is the use of microorganisms in seed inoculation, known as biopriming. The use of these microorganisms in seed inoculation leads to increased plant performance, especially if the microorganisms are symbiotic in the root zone of the plants. This study was aimed to investigate the effects of biopriming with Azospirillum and Azotobacter on drought resistance in fescue under greenhouse conditions. Osmotic potential at four levels was applied on the Fescue seeds using polyethylene glycol for 2 and 4 days as priming treatment along with inoculation with rhizobacteria. Drought stress was applied during the plant growth based on field capacity at four levels. The results showed that biopriming treatments caused improved performance and increased drought resistance compared to the control. The study showed that both Azospirillum and Azotobacter increased the performance significantly compared to the control. Generally, Azotobacter showed relatively better performance than Azospirillum. However, the Azotobacter treatments at 2 and 0.5 MPa for 2 days can be considered as a superior treatment in fescue as compared with other treatments.
Shole Haj agha Memar; Farshad Keivan Behjou; Kiomars sefidi; Behzad Behtari
Volume 23, Issue 2 , September 2016, , Pages 343-330
Abstract
The aim of this study was to investigate the impact of ecosystem change on emissions and carbon mineralization rate in Fandoghloo region. Soil sampling was performed at three depths (0-30 cm) from the grazing rangeland ecosystem, degraded rangeland ecosystem, and agricultural, ...
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The aim of this study was to investigate the impact of ecosystem change on emissions and carbon mineralization rate in Fandoghloo region. Soil sampling was performed at three depths (0-30 cm) from the grazing rangeland ecosystem, degraded rangeland ecosystem, and agricultural, ecosystem. Carbon dioxide emissions were measured during incubation with alkali absorption method. The highest and lowest emissions of carbon dioxide and carbon mineralization rate were obtained in the grazing rangeland ecosystem (0.968 mg CO2 g-1 soil and 0.00314 mol C kg-1 soil d-1), and the degraded rangeland ecosystem (4693 mg CO2 g-1 soil, and 0.0015mol C kg-1 soil d-1), respectively, showing a significant difference with other ecosystems at different depth levels. According to the results, significant differences were found for the activity of microorganisms in decomposition of organic matter in the study ecosystems. The dynamics of vegetation and returned fine roots caused high emissions of CO2 in soil of grazing rangeland ecosystem. In the agricultural ecosystem, due to the relatively wet conditions and failure to return organic matter to the soil, the decomposition of inaccessible organic matter caused to decreased soil organic matter and low carbon dioxide emissions.