نتایج جستجو برای: subsoiling at soil depth of 40

تعداد نتایج: 21402807  

2006
Randy L. Raper J. Mac Kirby

Soil compaction reduces rooting, infiltration, water storage, aeration, drainage, and crop growth. Soil compaction has been studied intensively for more than a century, and yet we still struggle with the effect that soil compaction has on crop production and the environment. In this article, we attempt to present the primary causes of soil compaction including trafficking weak soil, excessive l...

ژورنال: علوم آب و خاک 2008
عباس پلنگی, جمال, آخوند علی, علی محمد ,

For an appropriate drip irrigation system design, a prediction of soil wetting pattern is needed for a given soil texture. The wetting pattern geometry is a key factor for emitter distance determination as well as crop type. The geometry of the wetting bulb is dependent on the parameters such as soil hydraulic properties, emitter discharge and the irrigation time. This study has been conducted ...

Journal: :Journal of agricultural and food chemistry 2007
Sharon K Papiernik Scott R Yates William C Koskinen Brian Barber

Two-year field dissipation studies were conducted in three soil types in Minnesota to examine the processes affecting the dissipation of the herbicide isoxaflutole and its phytotoxic diketonitrile metabolite (DKN) under relatively cool, wet soil conditions. Plots of cuphea were treated with isoxaflutole and potassium bromide, a nonsorbed, nondegraded tracer. Replicate soil cores were collected ...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد گرمسار - دانشکده زبانهای خارجی 1389

previous studies have aimed at testing a hypothesis but the present study is data-first research in which researcher tries to form a theory from data rather than the use of data to test a hypothesis. this study aims at exploring teachers perceptions of the strengths and weaknesses of the current syllabus for college preparatory course. eight experienced teachers were selected to collect data du...

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

the purpose of this study was to examine the english language needs of medical students at tehran university of medical sciences . analysis of the needs took place for three groups: 320 undergraduate students, 30 postgraduate students and 20 university instructors. a triangulation approach to collect data was used in which a combination of the quantitative (using the questionnaires) and qualita...

Journal: :Global and Planetary Change 2021

Knowledge of the spatiotemporal dynamics soil temperature in cold environment is key to understanding effects climate change on land–atmosphere feedback and ecosystem functions. Here, we quantify recent thermal status trends shallow ground using most up-to-date data set over 457 sites Russia. The consists situ temperatures at multiple depths (0.8, 1.6, 3.2 m) collected from 1975 2016. For regio...

عباس پلنگی, جمال, آخوند علی, علی محمد ,

For an appropriate drip irrigation system design, a prediction of soil wetting pattern is needed for a given soil texture. The wetting pattern geometry is a key factor for emitter distance determination as well as crop type. The geometry of the wetting bulb is dependent on the parameters such as soil hydraulic properties, emitter discharge and the irrigation time. This study has been conducted ...

Journal: :international journal of agricultural science, research and technology in extension and education systems 2012
elham sirjani majid mahmoodabadi

soil detachment is known as an important process in soil erosion and its quantification is necessary to establish a basic understanding of erosion. this study was carried out to find the best flow erosivity indicator(s) for predicting detachment rate at low slopes. for this purpose, 12 experiments including 6 flow discharges (75, 100, 125, 150, 175 and 200 ml/s) and 2 slope gradients (1.5 and 2...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه لرستان - دانشکده ادبیات 1394

abstract the purpose of this study was to find out the effect of applying the principles of group-dynamic assessment (g-da) on learning of conditional structures in english by iranian efl learners at the intermediate level, which according to the formal educational system in iran, includes students who are in their second year of studying in high schools of koohdasht city. this study was a qua...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1392

toury (1978:200) believes that translation is a kind of activity which inevitably involves at least two languages and two cultural traditions. being polite while asking for something takes place differently in different cultures and languages, therefore various strategies may be applied for making requests and also translation of them in order not to disturb or threaten the face or better to sa...

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