نتایج جستجو برای: soil frost penetration depth

تعداد نتایج: 366860  

2017
Christian Rixen Veronika Stoeckli

Increasing production of artificial snow in ski resorts is controversially discussed, but only few investigations have been carried out systematically to specify the environmental impacts. We measured snow depth and density from groomed ski pistes (runs) with compacted snow and their effects on ground temperatures and timing of snowmelt. We analyzed groomed pistes with and without artificial sn...

Journal: :تحقیقات مهندسی کشاورزی 0
مجتبی نادری بلداجی دانشجوی دکتری پردیس کشاورزی و منابع طبیعی دانشگاه تهران رضا علیمردانی استاد دانشکده مهندسی بیوسیستم پردیس کشاورزی و منابع طبیعی دانشگاه تهران احمد طباطبایی فر استاد دانشکده مهندسی بیوسیستم پردیس کشاورزی و منابع طبیعی دانشگاه تهران احمد شریفی استادیار پژوهش مؤسسه تحقیقات فنی و مهندسی کشاورزی

soil compaction is an important aspect of agriculture and different methods are available to measure this parameter. one method is called the cone index; measuring the force required per unit area for penetration of a standard steel cone into the ground. cone penetrometers are used for cone index measurement. in this study, a tractor mounted, hydraulically-operated penetrometer was designed, bu...

Journal: :Remote Sensing 2017
Christian N. Koyama Hai Liu Kazunori Takahashi Masanobu Shimada Manabu Watanabe Tseedulam Khuut Motoyuki Sato

At radar frequencies below 2 GHz, the mismatch between the 5 to 15 cm sensing depth of classical time domain reflectometry (TDR) probe soil moisture measurements and the radar penetration depth can easily lead to unreliable in situ data. Accurate quantitative measurements of soil water contents at various depths by classical methods are cumbersome and usually highly invasive. We propose an impr...

Journal: :journal of agricultural science and technology 2015
i. małecka a. blecharczyk z. sawinska d. swędrzyńska t. piechota

the studies carried out over 2010-13 involved a static field experiment initiated in 1999 at brody research station of the poznan university of life science, poland. the soil tillage systems for winter wheat were compared on a soil classified as albic luvisols. the aim of experiments was to evaluate impact of ploughless soil tillage on some soil physical, chemical, biological properties and win...

Journal: :journal of rangeland science 2011
masoomeh abbasi khalaki mehdi moameri ali tavili mohammad jafari

some of arid regions problems of iran are saline and sodic soils. in improvement and reclamation of iranian arid rangelands, some foreign species of atriplex had been imported and adapted for many years ago. the most adapted species was atriplex canescens. at the present research, some environmental factors, vegetative characteristics (na, ca, mg and k), soil properties (moisture, ec, ph, solut...

Lack of sufficient information on conservation tillage systems leads to the dominating use of conventional tillage practice in most parts of Iran. Testing other management practices may help in decision making regarding the types of tillage systems that reduce soil deterioration. A three- years field experiment was conducted to study the effects of conventional (CT), reduced (RT) and no-till (N...

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