جستجوی مقالات مرتبط با کلیدواژه "bromus tomentellus" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

Range Seeding (Pit-Seeding) is one of the necessities of rangeland improvement in most of the semi-arid and temperate rangelands, which in many cases has not been very successful. Improving the growth and establishment of plants in these operations is very important. For this purpose, taking advantage of the coexistence of plants with arbuscular mycorrhiza fungi is one of the most effective methods in meeting the nutritional needs of plants and reducing environmental stresses such as drought stress. In order to investigate the effect of mycorrhiza fungus on morphological characteristics and nutrients of Bromus tomentellus, this study was conducted in the greenhouse and research farm of Malayer University. The experiment was performed randomly with 3 inoculation treatments with Rhizophagus intraradices and Funneliformis mosseae and no inoculation (control) and 30 replications in each treatment. Morphological factors studied in the plant included germination percentage, shoot and root dry weight, root and stem length and viability percentage. Nutrients included phosphorus, nitrogen, potassium, iron, manganese, zinc, copper and magnesium of plants, as well as plant protein and carbon were measured. The results showed that although inoculation with mycorrhiza had a positive and increasing effect on the studied factors, R. intraradices had a more additive effect on the factors than F. mosseae. So that for many factors, this increase was 2-3 times higher than the control treatment. Among morphological indices, stem height (51%), germination percentage (41%) and viability percentage (45%) had the highest and root length had the lowest increase compared to the control treatment. Also among the elements and nutrients Nitrogen (54%), phosphorus (24%) and protein (55%) showed the highest increase. Meanwhile, the element carbon in the treatment of R. intraradices like phosphorus had a significant increase (24%) but in the treatment of F. mosseae had the least increase compared to other elements (6.77%). Based on the results of this study, it is recommended to use R. intraradices in order to improve and increase the yield of planted species in rangeland rehabilitation and improvement operations.

Maximum allowable operating range of plants in different climatic conditions, fertile soils with different months in different seasons and in different degrees, because the pasture health is very variable. The purpose of this study was to determine the extent of utilization of Kordan key and the pastures are important. In this first region and a key area of ​​one hectare in area Kordan and In the first year and was grazed, and fencing. Selected and removed from any of 0, 25, 50, 75% and control is exercised (a basic 10 treatments). Monthly by the clipper and the area is grazing season. Effective utilization of changes in the phenological characteristics, forage and seed production, vitality, mortality and other characteristics of selected plant species is. Finally, the combined analysis of data with a split plot design in SAS software was analysed. Results of studies of the effects on forage production and harvest of Bromus tomentellus species studied showed The effect of different levels, different years, and their interactions on the production level is a significant percentage. This shows that in different years with different weather conditions of production are different. According to the research findings, permissible utilization limit of 50 percent in the aspect of plant health was found suitable in the Kordan region.

A field experiment was conducted to investigate the effects of mono and mixed culture on crude protein contents of Medicago sativa L. and Bromus tomentellus Boiss, total nitrogen, available phosphorus and potassium of soil using factorial experiment based on completely randomized design with 5 replications. Treatments consisted of three crop compositions (M. sativa, B. tomentellus or mixture of the two), three density levels (low (4 rows, row spacing 70 cm), Medium (8 rows, row spacing 30 cm) and high (16 rows, row spacing 14 cm). Results demonstrated that the forage crude protein in mixed culture was significantly higher than in monoculture of B. tomentellus (p 0.05). Percentage of plant crude protein decreased with increasing plant density both in monoculture and mixed culture. Medicago sativa monoculture and mixed culture increased soil fertility that confirms the importance of forage legumes in forage quality maintenance and preservation of soil fertility. According to the results, mixed culture of M. sativa and B. tomentellus with 8 rows density (30 cm row spacing) is recommended in dryland fields of Fereydoon-Shahr and similar areas.

This research was aimed to determine the allowable use of Bromus tomentellus, Festuca ovina and Stipa hohenackeriana in Firouzkooh rangeland during 2006 to 2010. Treatments included different harvesting intensities of 25%, 50%, 75% and control, performed on 40 medium-sized individuals of each species. Data were analyzed in a split plot in time design by SAS software and means were compared using Duncan. Results showed that the effects of treatment, year, and interaction effect of year*treatment were significant at 1% level of significance. In addition, the results of mean comparisons showed that the reduced forage yield was under the influence of harvesting intensities. In this regard, S.hohenackeriana and B.tomentellus were sensitive to drought while F.ovina was resistant to drought and more affected by the harvesting intensity. Our results clearly showed that a harvesting intensity of 25% and control treatment had no impact on the yield of species, leading to the reduced forage yield of the mentioned species. Therefore, an allowable use of 50% is recommended.

A field experiment was conducted to compare forage production of Medicago sativa and Bromus tomentellus species using factorial experiment based on the completely randomized design with 5 replications in the Fereydoon-Shahr research station, located in west part of Isfahan province in 2012. Treatments consisted of three crop compositions (M. sativa, B. tomentellus or mixture of the two), three density levels including low (4 rows), medium (8 rows) and high (16 rows)) in similar size plots and two planting date seasons (spring and autumn). Results indicated that autumn and spring planting of B. tomentellus and spring planting of M. sativa were more successful. The forage production of M. sativa and B. tomentellus in intercropping was significantly higher than in mono-cropping. The highest biomass production of both species per row was observed in 8 rows density and yield of intercropping per row was higher than mono-cropping per row, either. In the intercropping treatments, land equivalent ratio (LER) values were more than 1 for 8 and 16 rows density, indicated that land-use efficiency in intercropping was higher than in mono-cropping. According to the results, intercropping of M. sativa and B. tomentellus with 8 rows density (30 cm row spacing) is recommended in Fereydoon-Shahr poor dryland fields and similar areas.

In most Iranian rangelands, continuous grazing begins with melting snow and continues until the beginning of snow. This study was conducted to evaluate the effects of continuous grazing system on a number of morphological attributes of Bromus tomentellus and Ferula haussknechtii during 2010-2011 in Saral Rangelands of Kurdistan Province. The 30-year exclosure was selected as control area inside the Saral Research Station. In different growth stages, the morphological attributes including the shortest and longest basal area diameter, theshortest and longest canopy diameter, and the height of 10 plants were measured. The annual yield of 30 plants of each species in each year was clipped and weighed to determine forage consumption intensity. All data were subjected to statistical analysis in a completely randomized design using combined analysis. Mean comparisons were performed using Duncan’s Multiple Range Test. Continuous grazing caused to the increase of basal area diameter and canopy diameter of B. tomentellus significantly; however, the height varied in two studied treatments, depending on the year. The three studied morphological attributes of F. haussknekhtii were affected drastically by continuous grazing. In this species, basal area diameter was more affected by the conditions of the year. In both species, ungrazed plants used seasonable rainfall more efficiently as compared to the grazed plants.

This study aimed to evaluate the effects of various grazing intensities including non-grazing (as control site), moderate grazing and heavy grazing on aboveground and belowground biomass of Bromus tomentellus in Bijar protected area- Kordestan province. Regression techniques were used to assess the relationships of aboveground and belowground biomass of the species, and one-way ANOVA and Duncan's test were used to compare all the treatments. According to the results, there was a linear relationship between aboveground and underground biomass in the different treatments. Increasing grazing intensity leads to a significant reduction in aboveground, belowground and total biomass of the plant species. The species biomass in moderatly and heavily grazed sites declined 37% and 80% respectively in compare with the control. ‏‏‏‏‏‏The average total biomass in the control, moderately and heavily grazed sites were estimated 839, 488.75 and 132.88 kg/ha respectively. The relative contribution of aboveground and belowground biomass of the species were decreased and increased respectively as the grazing intensities were increased. The relative contribution of aboveground biomass in the control, moderately and heavily grazed sites were 54.97%, 61.42% and 64.34% respectively. The relative contribution of belowground biomass in the control, moderately and heavily grazed sites were 45.03%, 38.58% and 35.66% respectively. The results of this study highlight the importance of controlling the grazing intensities to prevent soil erosion and losing the valuable plant species.

To evaluate the vegetative and productive characteristics and forage consumption by livestock at different stages of Bromus tomentellus phonology, this experiment was carried out during five years in Urmia-Garebagh rangelands. Thus starting the grazing season and livestock entering, any remaining amount of forage grazing was harvested until a month intervals, and consumption rate was determined by subtraction between harvested forage and fenced plot forage. Finally, in order to study the effect of harvest months on the production and consumption of species under investigation in the study area, data were analyzed. ANOVA combined data showed that overall because of hot weather in 87 and 89 the second and fourth year was highest production years and sixth month of forage production (biomass) was the lowest production through the months, but the second month has highest consumption of the grazing season.

The recognition of different phenological stages of valuable rangeland species is highly important for grazing planning. It also assists managers to adjust the grazing period in accordance with the time of phenological stages of the species with high palatability and nutritive value and also detect the appropriate time for seed collection. Phenological stage of Bromus tomentellus were studied at 12 different vegetative regions within different sites during 2007-2010. The site characteristics of each location were recorded and 10 B. tomentellus plants were selected to study the phonological changes. The growth, flowering, seed maturity, and drying stages of the species were recordedevery other week and once a week in growing and reproductive stages, respectively. Ombrothermic curves of the studied areas were drawn using the meteorological data of the nearest synoptic station and were used to compare with different phenological stage of B. tomentellus. According to the results, in some years (2008, 2009 and 2010), especially in dry and warm weather condition in 2008, phenological stages of the species started and finished 1 to 3 weeks earlier than the wet years. In a relatively wet year (2007) the growth period and fall regrowth of the species was longer than normal years. The results indicated that vegetative growth in good rainfall condition differed from late March to early April and consequently flowering, seed maturity and drying stages were delayed with increasing altitude. Also, the species in sites with similar altitude had the same phonological periods. These results can be used by range mangers to adjust the grazing program and identify the appropriate time of seed collections for restoration projects.

Available soil moisture has great influence on rangeland production and it highly depends on the types of soil texture. This study aimed to evaluate the effects of soil texture on Bromus tomentellus yield. The relationships between some soil properties with soil texture were also studied. Geomorphology methods and GIS techniques were used to provide land unit maps in scale of 1:25000. In each unit, the amounts of pH, EC, N, P, K, OC, %CaCo3 and soil texture of soil samples were measured. The B. tomentellus yield was also measured in all unites. Vegetation cover of the species were then studied in 15 plots (1m2) along two 150 meters transects. Analysis of variance and Duncan test were used to compare the water availability in different soil textures. According to the results, soil water capacity in “clay” and “loamy sand soils” were 0.2 % and 0.1% respectively. It indicated that clay soils are able to store higher water contents. Electrical conductivity, pH, and organic carbons of soil samples in different texture types did not vary significantly but other studied soil properties were different. The land units dominated by “loam” and “loamy sand” soil texture had highest 18/63 kg/hec) and lowest (3/71 kg/hec) B. tomentellus yields.

In this study the effect of month, place and different years on the preferencevalue of Bromus tomentellus in semi-steppe region was studied. The preferencevalue of the Bromus tomentellus was studied in two years and four months in three sites as cheshme anjir (Fars), Badamstan (Zanjan) Firuzkuh (Tehran). To determine the preferencevalue of species the two methods of as preference index and timing method was used. To compare preferencevalue in different sites times the factorial completely randomized design was used. Mean comparison was performed using Duncan's Multiple Range Test at 5% level. And to compare two methods whit each other the T test was used. The results of preference index showed that sites were significant at 1% level. But the other factors were insignificant differences according to the results of timing method all the factors were insignificant. Comparison of two methods by T test showed that the two methods were different.

Environmental stress especially drought is one of the most important factors to reduce and disturbance in different stages of floral growth especially sprouting in dry and semi-dry lands of Iran. For this purpose a factorial essay executed in accidentally manner with four iterations in vitro condition. Four genotypes of Bromus tomentellus pasture types were used (92 Tehran, 630 Kordestan, 3414 Shahrekord and 9507 Lorestan) and four drought care (-3, -6 and -9 times distilled water). In this essay the sprouting percentage, Root length, Shoot length, Seedling length, Root length to Shoot length rate, Seedling dry weight, Seedling fresh weight, dry to fresh weight rate sprouting rate and seed health index were determined. The result showed that the with stress drought increase, all attributes except the dry weight to fresh weight proportion reduced significantly. The reduction in all under assessment properties were from -3 to -6 in potential. In general, in tested genotypes, Lorestan (9507) genotype showed a better sprouting in under study potentials and had a meaningful preference to other genotypes. From assessed parameters, Seedling length and seed index standard showed the most possible reaction to changing potential of water. The best levels to assess the stability to drought were the -6 and -9 load potentials in all drought levels.

To study the effect of different harvesting intensity on forage production of Bromus tomentellus was considered of Majid Abad Qorveh. Treatments included four harvested intensity 25, 50 and 75 percent and control (no harvest).Data were analyzed based on splitplot over time during four years(1386-1389) using SAS and IRRISTAT software. The results showed that the main effect of year, different harvesting intensity and interactions effect of different harvesting intensity and years are significant on forage production and vitality of Bromus tomentellus. Comparing the harvesting intensity of 50 and 25 percent indicated no significant difference between them. The highest intensity of production is harvest intensity of 25 percent with 390 mm perecipition in 1389 and the lowest harvest intensity is 50 and 75 percent with170 mm perecipition in 1387. Regarding to AMMI Analysis, the first interaction principal component(IPC1) had a significant effect and express a 93/6 percent of the interaction of the sum of squares. The first main component biplot interaction showed that the 25 percent treatments had a highest average production and stability is relatively good, control treatment had a lowest stability and 75 percent treatment had a highest stability. According to the results, to preserve the production and vitality of Bromus tomentellus the harvesting intensity of 25 percent is recommended.

Rangelands are the largest of the earth''s natural resources that the use of them with proper management can be affordable in terms of economic and agricultural. Due to the successful results of cultivation of some grasses including Bromus tomentellus in Gharabagh of West Azerbaidjan، the determination of allowable use for Bromus tomentellus can be useful in conservation and proper utilization of the mentioned species as well as ensuring its survival. Treatments in each block were four grazing intensities of 25، 50، and 75% and control (no harvest). In each treatment، 10 individuals of species were considered as replications. Data were analyzed in a split plot in time for four years (2007-2010) by SAS & IRRISTAT software. Results showed that the effect of year، different harvesting intensities and interactions between year and different harvesting intensities on forage production and vitality of Bromus tomentellus was significant at 1% level of probability. No significant difference was found between control treatment and grazing intensity of 25 percent as well as 25 and 50 percent. With increasing harvesting intensity to 50 and 75 percent، average rate of production decreased significantly compared to control. Average production and vitality showed a downward trend during 2007-2010 due to the severe reduction of average production and vitality at 75% harvesting intensity. Other treatments including control، 25، and 50 percent، showed almost similar trend during the four years. Based on AMMI analysis، first interaction principle component (IPC1) was significant at 1% level of probability and explained 99. 19% of interaction sum of squares. According to the biplot of first interaction principle component and average production، the least production and stability was obtained at 75% harvesting intensity while maximum stability was recorded for 50% harvesting intensity. According to the results، a harvesting intensity of 50% is recommended for Bromus tomentellus in the region so that health and vitality of this species is preserved during the harvesting years.

The goal of this research is to compare the quality of litter and aerial organs in three rangeland species including Bromus tomentellus, Agropyron tauri and Psathyrostachys fragilis on the basis of nitrogen, phosphorous, potassium, carbon amounts and C/N proportion. After recognition of the species sites in Taleghan Watershed, litter and aerial organs of the mentioned species were collected. Sampling was done in key areas of each site along four transects using randomized-systematic method. Transect length was determined according to the area and variation of the key region.. Ten plots were placed along each transect and the dimensions of sampling plots were selected on the basis of species type and distribution using minimal area method. The obtained results of analysis of variance and comparison of means showed that B. tomentellus has maximum amounts of carbon and C/N proportion in its litter while P. fragilis has maximum amount of phosphorous and finally the maximum amount of nitrogen in litter is related to A. tauri. Meanwhile, P. fragilis showed maximum amounts of nitrogen, carbon and C/N proportion in its areal organs. The highest amounts of phosphorous and potassium are related to B. tomentellus. Totally A. tauri species showed the better condition than other species based on quality of litter and aerial organs.

Russian brome (Bromus tomentellus) is a prennial grass with good adaptability to climatic condition of north Khorasan. So, it has promise for using in range improvement projects. Because threre is no enough local information about mangement of this plant, the present experiment has been conducted in Sisab Reaserch Station (SRS) to evaluate the response of this species to grazing intensities and rest grazing. Four grazing intensities of light (20 to 45% of forage removal), moderate (45- 65% of forage removal), heavy (65- 80% of forage removal) and without grazing as control applied by herd of lamb and sheep for three consequent years from 1999 to 2001. The year of 2002 considered as rest period from grazing. Herbage mass and number of plant per unit area measured as an index response. Herbage mass production decreased by reduction in precipitation. Heavy grazing resulted in significant reduction in herbage production and number of plants per unit area, but one year rest from grazing componsated the negative effect of intensive grazing on herbage mass reduction. Management implication based on this results show that plant can tolerate grazing intensity by 45-65% of herbage removal and indicate on the importance of rest grazing on survivance of this plant.