Ali Farahani; Ali Tavili; Hosein Arzani; Hosein Azarnivand; Aliashraf Jafari
Volume 30, Issue 2 , September 2023, , Pages 214-229
Abstract
Background and objectives The germination and establishment of plants resistant to drought is one of the most important and effective aspects of rangeland improvement. Investigating changes in rangeland species' morphological and physiological characteristics under different pretreatments under ...
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Background and objectives The germination and establishment of plants resistant to drought is one of the most important and effective aspects of rangeland improvement. Investigating changes in rangeland species' morphological and physiological characteristics under different pretreatments under laboratory, greenhouse, and field conditions is necessary. As a result, elite and promising species can be selected, and improvement efforts can be evaluated favorably. Methodology This study investigated the effect of different pretreatments on the germination and establishment of Sanguisorba minor and Elymus hispidus under drought stress. In this regard, the effect of priming treatments with distilled water, polyethylene glycol, potassium nitrate, and silver nanoparticles was studied to improve germination characteristics and establishment of species under agricultural capacity. The experiment was conducted as a factorial in a randomized complete block design in four replications. To conduct the research, 168 pots were used, and ten seeds were planted in each pot. The measured attributes included the percentage and velocity of seedling appearance from the soil, establishment and survival, length and weight of root and stem, vigor, proline, carotenoid, soluble sugar, total chlorophyll, catalase, and superoxide dismutase enzymes. After sampling the studied traits in the greenhouse and obtaining the results in the laboratory, variance and data analysis in SPSS software. A comparison of mean data with Duncan's multiple range tests at a 5% level for the studied traits was performed on both species. Results The results showed that drought stress significantly differs in characteristics, such as the dry weight of aerial parts or the length of plant roots. The mutual effects of priming and stress were significant on the traits of emergence from the soil, speed of emergence, establishment, survival, and dry weight of aerial parts. Still, it affected several other traits as well. The application of silver nanoparticles had positive or negative effects on seeds' vegetative characteristics, and seedlings grown from the seeds of the studied plants did not show significant changes to characteristics such as plant root length under different priming treatments at a specific moisture level. Some characteristics, including ability, had significant changes due to humidity levels varying up to 20 percent. The positive effects of polyethylene treatment and the negative effects of high nanoparticle concentration were evident. Applying polyethylene glycol and potassium nitrate in E. hispidus and polyethylene glycol and silver nanoparticles at a concentration of 30 mg/l in S. minor showed the highest positive effects on plant resistance under drought stress. Application of silver nanoparticles at concentrations of 60 and 90 mg/L showed negative effects on the vegetative and physiological characteristics of the two studied species. Conclusion drought stress caused negative effects on the structural characteristics of the studied species, and using hydropriming treatments, potassium nitrate, polyethylene glycol, and silver nanoparticles (with a concentration of 30 mg/liter) reduced stress adverse effects. The reason for this is mainly the changes in the physiological factors, such as the amount of proline, catalase, and superoxide dismutase enzymes, and the application of various pretreatments causes positive changes in pretreatment factors and increases the species' drought resistance. The results related to the effect of different pretreatments on the germination of the mentioned species under laboratory and field conditions also confirm this issue.
Abbas Darini; Mohammad Jafari; Ali Tavili; Hosein Arzani; Seyed Akbar Javadi
Volume 30, Issue 2 , September 2023, , Pages 318-334
Abstract
Background and objectives Although man-made biochars positively affect soil properties and plant performance, their preparation and use, especially on a large scale, are costly. On the other hand, mineral biochar can be considered an alternative method. However, there is no information about the ...
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Background and objectives Although man-made biochars positively affect soil properties and plant performance, their preparation and use, especially on a large scale, are costly. On the other hand, mineral biochar can be considered an alternative method. However, there is no information about the effect of this type of biochar and its method of use on soil characteristics and plant performance. Materials and methods Effect of levels of 0 (control), 5, 12, and 25% of mineral biochar (obtained from the mine of Koohbanan city, Kerman province) in three forms of use (including mixed with surface soil, mixed with deep bottom soil, and mixed with total volume soil) on the vegetative performance of bush Fortuynia bungei, shrub Calligonum comosum and tree Ziziphus spina-christi were evaluated in a completely randomized factorial design in the nursery during four months. Cultivation operations in two stages included the germination section (without biochar) and studying the treatments' effects on the species' vegetative characteristics. The seeds were planted in pots containing 100 grams of sand. After sprouting the seedlings and their three to five leaves, one seedling was selected from each pot and transferred to larger pots containing biochar. The amount of water required was determined based on the measurement of soil field capacity. Seedling characteristics were measured at 20-day intervals for four months, and biomass production was measured at the end of the experimental period. At the end of the test period, some soil properties were examined, including organic carbon, total nitrogen, absorbable phosphorus, absorbable potassium, acidity, and electrical conductivity. Results The application of different levels and the manner of using biochar to the evaluated characteristics showed that the most noticeable effect was related to the level of biochar. In other words, although using biochar or the cultivated species resulted in varying results, the amount of biochar had the greatest effect on the evaluated characteristics. The findings showed the effect of higher levels of biochar and the mixture of biochar with the total soil volume on plant species performance (Sig.0.005). Also, the species performed differently, so C. comosum had the highest growth height (65 cm), and F. bungei had the lowest growth height (19 cm). The method of using biochar also had a significant effect on plant biomass, so the highest biomass was related to F. bungei (9.2 grams) under the influence of 25% biochar mixed with the entire soil profile. The levels of biochar or plant species alone affected soil properties. However, the combined effect of the species and the level of biochar used on soil properties was not noticeable. With the application of 25% of biochar, nitrogen (from 0.14 to 0.25%), organic matter (0.88 to 4.1%), and electrical conductivity (0.76 to 1.33 dS/m) showed the most changes (Sig.<0.001). Conclusion By increasing biochar levels, improved soil properties and plant performance were observed. On the other hand, biochar application affects plant performance depending on species. The method of using biochar also significantly changed the performance of cultivated plants so that, considering the economic discussion of using biochar, its mixture with the entire soil profile leads to higher production than mixing biochar with surface or deep soil. However, more studies are needed regarding biochar's effect on soil properties and plant performance.
Yaser GHasemi Arian; Hosein Azarnivand; Ali Tavili
Volume 28, Issue 1 , April 2021, , Pages 82-92
Abstract
The search for the technical perspectives of the country's natural resources management depicts the important fact that management approaches play a very important role in the protection, rehabilitation, and sustainable use of these resources. In this regard, the present study was conducted ...
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The search for the technical perspectives of the country's natural resources management depicts the important fact that management approaches play a very important role in the protection, rehabilitation, and sustainable use of these resources. In this regard, the present study was conducted to evaluate and compare the ecological indicators of rehabilitated rangelands under two types of ecological-oriented and socio-ecological-oriented management approaches. For this purpose, the international carbon sequestration project and the desertification project of Sarbisheh plain were selected as two projects with socio-ecological-oriented and ecological-oriented management approaches, respectively. Then, in the executive scope of each project, three types of rangeland improvement operations, including plantation, crescent construction, seeding, and sowing were selected, and the percentage of vegetation, the amount of forage production, and carbon sequestrated in the soil were the basis for evaluation and comparison. Vegetation was measured by the linear transect placement method, production amount was measured by the double sampling method, and soil carbon was measured by Wallace and Blake method. The results of the analysis of variance showed that the interaction between the type of management and corrective operations on the value of ecological indexes was a significant difference at (p < /em><0.01). The highest value of indexes was observed in social-ecological-oriented management based on plant operations, and the lowest value was observed in ecological-oriented management under the same activity. The results show that capacity building, institutionalization, and real participation of the local community in all stages of planning, implementation, monitoring, and operation of these areas, in the socio-ecological management approach, bring more success in improving the index of ecological rangelands.
Mahdokht Allahmoradi; Hosein Arzani; Ali Tavili
Volume 27, Issue 1 , April 2020, , Pages 13-23
Abstract
Determining grazing capacity of rangelands is one of the main factors in range management so that, regarding this important factor, is one the main causes of range degradation in Iran. Middle Taleghan rangelands have utilized for many years thus, there aren’t preserved from degradation. The aim ...
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Determining grazing capacity of rangelands is one of the main factors in range management so that, regarding this important factor, is one the main causes of range degradation in Iran. Middle Taleghan rangelands have utilized for many years thus, there aren’t preserved from degradation. The aim of this research was to determine the short term grazing capacity of these rangelands to show factors affecting grazing capacity and both preserve and improve the condition of them. During the field work was done in June 2013, sampling performed by random- systematic method using four 150 meters transects and 10 plots along each one randomly and current forage production was harvested in separation of each species form all three palatability classes. Then proper use factor was determined. Finally, short term grazing capacity was calculated through the computing daily requirement energy method and attending to forage quality for each type. The results are shown that grazing capacity range from 0 to 1534 Fashandi race adult sheeps for grazing period. Least required area for a sheep grazing range from 1.92 to 8.63 hectares for grazing period. Grazing capacity for all of studied rangelands is equal to 6802 Fashandi race adult sheep by 60.7 kg weight and least required area for a sheep grazing is 3.76 hectares in average, Whereas the actual grazing capacity in these rangeland is mostly 159 Fashandi race adult sheeps per hectar for good condition ranges ang 19 for poor condition ranges. So, For calculating grazing capacity it is also necessary to consider palatability, proper use factor, forage quality, animal weight and its daily requirement and its movment rate in addition to rangeland yield. Thus, current research is emphasizing on to pay attention toward all effective factors in evaluating rangeland grazing capacity.
Mojtaba Akhavan Armaki; Hossein Azarnivand; Mohammad Hasan Asareh; Ali Ashraf Jafari; Ali Tavili
Volume 19, Issue 4 , March 2013, , Pages 669-678
Abstract
Drought has a major influence on morphological and physiological characteristics of plant species. Drought stress has a direct relationship with germination characteristics including germination percentage, seedling length (mm/plant), root to shoot ratio, seedling weight (g), ratio of dry weight to fresh ...
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Drought has a major influence on morphological and physiological characteristics of plant species. Drought stress has a direct relationship with germination characteristics including germination percentage, seedling length (mm/plant), root to shoot ratio, seedling weight (g), ratio of dry weight to fresh weight of seedlings (g.dfw-1) and seed vigor index (V). In this research, effects of drought stress on these characteristics were examined in four genotypes of Bromus inermis (Alborz 303, Mazandaran 3151, Firozkuh 3966 and Esfahan 200060) under laboratory and greenhouse condition. In greenhouse experiment, three physiological traits including chlorophyll, carbohydrates and proline contents were measured. Drought treatments included four levels of osmotic potential (0, -0.3, -0.6 and -0.9 MPa) in germinator and four levels of osmotic potential (FC, 25% FC, 50% FC and 75% FC) in greenhouse, made by Poly-Ethylene-Glycol (PEG 6000) solution in laboratory and weighting method in greenhouses, respectively. Results showed that Esfahan (200060) genotype was better than two other genotypes in terms of germination percentage under two conditions. Increasing drought stress increased proline and carbohydrate and decreased the chlorophyll content.