نتایج جستجو برای: some perennial plants may cause accumulation of seed bank under their canopy

تعداد نتایج: 21397331  

ژورنال: علوم زراعی ایران 2020
Bagheri, Alireza, Mondani, Farzad, Nosratti, Iraj, Zargarian, Negin,

Weeds are one of the most important factors in reducing yield in legumes crops. Therefore, awareness of the interaction between weeds and crops as well as identification of their spatial variation pattern in the field is important. To investigate the the effect of  weeds on seed yield of lentil, and also to study the spatial distribution pattern of weeds under rainfed conditions, a field experi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی 1392

flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

2012
C. Zambrano-Navea J. L. Gonzalez-Andujar

Phalaris brachystachys is a common and troublesome weed in winter cereals in Mediterranean countries. A deterministic model was developed to simulate P. brachystachys seedbank dynamics in the wheat-sunflower rotation, a commonly practiced cropping system in southern Spain, under different herbicide-based management scenarios: no herbicide application, full herbicide dose (standard rate) and two...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1393

nowadays, technical terminology translation plays an important role in human life. specific groups of people all over the world refer to learn these terminologies in order to be familiar with a subject and improve their knowledge in that domain. on the other hand, saving the technical translation equivalent is a particularly salient challenge for technical translators. the present study was con...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیخ بهایی - دانشکده ادبیات، زبانهای خارجی و تاریخ 1391

the present study sought to examine whether a task-based approach could have an impact on raising awareness of collocations. moreover, it sought to investigate the facilitative role of consciousness-raising tasks of collocations in the communicative instances of use. to this end, 68 intermediate learners of english were selected via a placement test. the participants were taught with classroom ...

Jamshid Khatir Namany Morteza Akbarzadeh, Seyyed Ali Hosseini

Studies on vegetation changes of rangelands under grazed and non-grazedconditions are of great importance in the range management planning programs. To determinethe change process of vegetation, this study was performed in Inche Shorezar site of Golestanprovince for nine years (1997-2005). The vegetation parameters were measured every year inseveral fixed plots inside and adjacent of exclosures...

2010
Chad S. Boyd Kirk W. Davies

Woody plants can cause localized increases in resources (i.e., resource islands) that can persist after fire and create a heterogeneous environment for restoration. Others have found that subcanopies have increased soil organic matter, nitrogen, and carbon and elevated post-fire soil temperature. We tested the hypothesis that burned sagebrush subcanopies would have increased seedling establishm...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده ادبیات و زبانهای خارجی 1393

the purpose of this study was to find the relationship between critical thinking and self-regulation with reading comprehension of iranian female elementary language learners. the present study is a correlational one having a descriptive design. two questionnaires, critical thinking questionnaire and self-regulation questionnaire which were valid and reliable questionnaires and four reading com...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه یزد - پژوهشکده ادبیات 1392

abstract the aim of the present study is to explore the impact of the cognitive reading strategy instruction on learners reading self-efficacy and their reading achievement. in order to fulfill this purpose, from 120 participants, 90 intermediate efl learners as an experimental group were chosen from three different educational settings namely, yazd university, yazd science and art un...

2007
Elizabeth A. Allen Robert S. Nowak

As pinyon–juniper (specifically, Pinus monophylla and Juniperus osteosperma) woodlands in the western United States increase in distribution and density, understory growth declines and the occurrence of crown fires increases, leaving mountainsides open to both soil erosion and invasion by exotic species. We examined if the loss in understory cover that occurred with increasing tree cover was re...

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