Mohammad Daneshi; Mojgansadat Azimi; Hamid Niknahad Gharehmakhor; Elham Faghani
Volume 30, Issue 4 , February 2024, , Pages 542-556
Abstract
Background and objectivesDue to the increase in the consumption of fossil fuels and chemical fertilizers, especially nitrogen-containing fertilizers, the entry of nitrogen into the cycle of ecosystems has been more than normal.Nitrogen deposition as a consequence of increasing nitrogen input to the atmosphere, ...
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Background and objectivesDue to the increase in the consumption of fossil fuels and chemical fertilizers, especially nitrogen-containing fertilizers, the entry of nitrogen into the cycle of ecosystems has been more than normal.Nitrogen deposition as a consequence of increasing nitrogen input to the atmosphere, can be a threat to ecosystems. It can affect soil properties, soil microorganisms and their activities, vegetation and animals. The aim of the present study is to investigate the effects of deposition of different rates of atmospheric nitrogen on the biochemical properties of a summer rangeland's soil. Methodology For this purpose, the seeds of Medicago sativa were planted in 36 pots containing rangeland soil in a completely randomized block design. Two months after seed germination in pots, six Nitrogen treatments included control,30, 60,90,120 and 150 kg ammonium nitrate/ha which dissolved in water were applied in 6 replications during a period of 75 days. At the end of experiment, some soil biochemical properties (acidity, electrical conductivity, absorbable phosphorus, total nitrogen, organic carbon and exchangeable potassium along with biomass and microbial respiration) and Root weight and depth factors were measured. Data analysis was done using analysis of variance method and mean comparison was done using Duncan's test. ResultsThe results demonstrated that increasing the level of ammonium nitrate deposition to 60 and 90 kg per hectare per year, despite the significant increase (p < 0.05) of organic carbon and total soil nitrogen, causes a significant decrease in other measured biochemical properties of the soil (p < 0.05). An increase in nitrogen deposition in the early stages may be partially responsible for root growth, but with nitrogen saturation in the soil and the occurrence of nitrate leaching, as well as the loss of soil fertility, unfavorable conditions for root growth are provided. With the increase of nitrogen deposition in the soil, up to the level of 60 kg /ha, the average respiration and microbial biomass increased, But at higher levels of nitrogen deposition, respiration and microbial biomass decreased.ConclusionIn case of an increase in mineral nitrogen deposition in the studied area, it is recommended to use the Medicago sativa in the improvement of vegetation restoration projects of summer rangelands to absorb the deposed mineral nitrogen in excess of the soil holding capacity, its alleviate negative consequences and creating a suitable root zone for the the activity of soil microbial.
Mahshid Souri; mirfarhad blurfrush; Hirad Aghbari; javad motamedi; Behnaz Attaeian
Volume 27, Issue 3 , October 2020, , Pages 369-409
Abstract
If the rangeland forage is used continuously, the important elements such as NPC do not return to the soil, which will cause the rangeland lands to lose their fertility. Therefore, nowadays, in the field of rangeland management, rangeland improvement and rehabilitation has become ...
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If the rangeland forage is used continuously, the important elements such as NPC do not return to the soil, which will cause the rangeland lands to lose their fertility. Therefore, nowadays, in the field of rangeland management, rangeland improvement and rehabilitation has become very important. The use of fertilizers is one of the methods to rehabilitation the rangelands. If the proper fertilizer application is carried out in accordance with the climatic conditions, cover condition, and soil characteristics, it will improve the rangeland. Otherwise, it will increase the concentration of salts, soil toxicity, and surface and groundwater contamination and leads to drying of the plants. The aim of this study is to present a model based on the use of an artificial neural network that expresses the relationships between organic carbon, nitrogen and phosphorus of rangeland soil and plant factors, based on which, it is possible to estimate the mentioned elements in the rangeland ecosystems without statistics to manage fertilization. Based on the results, organic carbon, nitrogen and phosphorus of the soil were estimated in the Nazlocha rangeland of Urmia. Eight factors of electrical conductivity, acidity, clay percentage, silt percentage, sand percentage, lime content, production and canopy cover percentage of rangeland plants were also selected for factor analysis. Therefore, according to the mentioned results, the neural network was able to accurately predict the amount of organic carbon, nitrogen and phosphorus in rangeland soils. According to the results, the vegetation type Astragalus gummifera-prangos uloptera-Bromus tomentellus requires phosphorus and nitrogen fertilizers. Onobrychis cornuta- Festuca ovina-Thymus kotschyanus requires phosphorus fertilizer, and Astragalus macrostachys-Noeae mucronata-Stipa barbata requires organic matter and nitrogen and phosphorus fertilizers.
Farhad Azhir; Moham,mad Fayaz
Volume 26, Issue 4 , December 2019, , Pages 932-940
Abstract
In program of increasing forage production in rangelands of the country, gathering and deepening knowledge of forage plants establishment is necessary. So seeds of Trifolium pratense species prepared from Sari city market and cultivated. The purpose of this study was to determine the optimal season and ...
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In program of increasing forage production in rangelands of the country, gathering and deepening knowledge of forage plants establishment is necessary. So seeds of Trifolium pratense species prepared from Sari city market and cultivated. The purpose of this study was to determine the optimal season and efficient method of species establishment for rangeland breeding in steppe rangelands. Experiment was performed in Posht-kooh water spreading station with 350 mm precipitation and semi-arid-cold climate. For this purpose, two sowing treatments including of seeding and seed spacing in two cultivation season of fall and spring, in split plot based on completely randomize block design in three repetitions were performed. Results indicated that there was a significant difference at (p<0.01) between the cultivation season and two cultivation methods. Germination and viability in fall season (39.11% germination, 13.83% viability) were more preferable to spring cultivation (30.06% germination, 11.83% viability). Seed cultivation in seeding (germination 39.22%, 14.78% viability) was also superior to seed spacing (29.94% germination, 10.89% viability). According to the obtained results, fall cultivation and seeding method were better than spring cultivation and seed spacing method. There is possibility of breeding rangelands in similar climatic and physical properties of the rangelands at the test site as well as fall cultivation and seeding method to increase forage production and direct grazing.
Mahshid Souri; Ehsan Zandi Esfahan; Nadia Kamali
Volume 25, Issue 3 , November 2018, , Pages 524-535
Abstract
Investigating the effect of environmental factors on the yield of forage plants is one of the necessities for improvement, rehabilitation, and development of rangelands. Festuca ovina is of perennial grasses. This species is found to be abundant in the semi-steppe rangelands of the country due to its ...
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Investigating the effect of environmental factors on the yield of forage plants is one of the necessities for improvement, rehabilitation, and development of rangelands. Festuca ovina is of perennial grasses. This species is found to be abundant in the semi-steppe rangelands of the country due to its adaptability to dehydration and low temperatures of -20 ° C. This rangeland species plays an important role in providing forage, soil stabilization, erosion prevention, and soil conservation in semi steppe rangelands. Therefore, the purpose of this study was to investigate the effect of salinity and pollutant factors on the performance of Festuca ovina. This experiment was conducted in greenhouse conditions in a factorial arrangement based on a completely randomized design under the influence of the first factor of copper oxide treatment at two levels (50 and 100 mg / l), copper nano-oxide at two levels (50 and 100 mg / l), and control treatment, and the second factor of sodium chloride treatment at three levels (0, 200 and 400 mM) in five replicates on Festuca ovina in a hydroponic greenhouse. After two months of stress, changes in chlorophyll, potassium and air length were measured. Data were analyzed using a factorial experimental design and SNK multiple range test in SPSS.18 software. According to the results of this study, the Festuca ovina species, in addition to the ability to establish and grow in each of the conditions of salinity and pollutant stress, has the ability to establish in both conditions (salinity + pollutant). Therefore, it can be of particular interest to planners, managers of natural resources and the environment and recommended as a consistent species to improve the rangelands of these regions.
Mirtaher Ghaiemi; Abassali Sandgol
Volume 15, Issue 1 , January 2008, , Pages 13-25
Abstract
The major objective of this research was to evaluate the effect of the 5-year exclosure at Goladam station of Salmas rangelands.Vegetation type and dominant species of this area was Bromus tomentellus and Festuca ovina. Changes in total forage production, plus canopy cover percentage, range condition ...
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The major objective of this research was to evaluate the effect of the 5-year exclosure at Goladam station of Salmas rangelands.Vegetation type and dominant species of this area was Bromus tomentellus and Festuca ovina. Changes in total forage production, plus canopy cover percentage, range condition and trend of this rangeland were measured, evaluated and then analysed statistically. Results of this study indicated that range condition and trend of this rangeland improved considerably. Total plant cover and forage production of the protected area increased.Vegetation cover and density of the plant species class I and IIincreased whilespeciesclass IIIdecreasedconsiderably throughout the study period. It seems that the 5-year exclosure is an appropriate exclusionperiod for this area. Further investigations are recommended for find decisions.