نتایج جستجو برای: soil bulk density

تعداد نتایج: 646486  

The effects of traffic frequency and skid trail slope on dry bulk density, litter mass and rutting are examined. Treatments included a combination of four different traffic frequencies (3, 7, 14, and 20 passes of a rubber skidder) and three levels of slope ( 20%.) The results showed that dry bulk density, rut depth and soil displacement increased with the increase of traffic frequency and slop...

Journal: :international journal of civil engineering 0
s.a.o. hosseini forestry dep. - mazandaran prov. sari-(9th km)farahabad road-sari agricultural and natural resources university m. nasiri forestry dep. - mazandaran prov. sari-(9th km)farahabad road-sari agricultural and natural resources university m. akbarimehr forestry dep. - mazandaran prov. sari-(9th km)farahabad road-sari agricultural and natural resources university

harvesting of timber using ground based machinery is still a common practice around the world. track and road building, and movement of machinery during harvesting operations cause soil disturbance. therefore the aim of this study was to investigate the change in soil properties after logging operation on skid trails (2 years and 7 years after logging) and compare disturbed soil properties with...

Journal: :journal of agricultural science and technology 2012
s. f. mousavi m. moazzeni b. mostafazadeh-fard m. r. yazdani

the prevalent method of irrigation in paddy fields in iran is continuous ponding, which changes to intermittent method at the time of water shortage. soil cracks are the main problem in intermittent irrigation. in this study, effects of adding rice straw on some soil physical characteristics and cracks were studied in paddy soils of the guilan province of iran. the experiment was performed as s...

ژورنال: علوم آب و خاک 2003
عباس همت, , محمدرضا مصدقی, , محمدعلی حاج‌عباسی, ,

Soil tilth is crucial to seedling emergence, plant growth, and crop yield. Soil tilth of unstable soil is very susceptible to change. Internal forces originating from matric suction can change soil physical properties. A laboratory study was conducted on pots of a surface silty clay loam soil of Khomeinishahr series (fine-loamy, mixed, thermic Typic Haplargids, USDA), located in Research Farm o...

Journal: :محیط زیست طبیعی 0
مقداد جورغلامی استادیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران

in forest harvesting, there is an ongoing trend to increase constantly the size, power and load of logging machines. this may cause soil degradation in forest ecosystems as the passes of these machines modify important soil structural characteristics. the present study was conducted to examine impact of skidding traffic, trail slope, traffic frequency, and soil depth on bulk density and soil co...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه گیلان - دانشکده علوم کشاورزی 1388

چکیده ندارد.

عباس همت, , محمدرضا مصدقی, , محمدعلی حاج‌عباسی, ,

Soil tilth is crucial to seedling emergence, plant growth, and crop yield. Soil tilth of unstable soil is very susceptible to change. Internal forces originating from matric suction can change soil physical properties. A laboratory study was conducted on pots of a surface silty clay loam soil of Khomeinishahr series (fine-loamy, mixed, thermic Typic Haplargids, USDA), located in Research Farm o...

Journal: :آب و خاک 0
وحید یزدانی بیژن قهرمان کامران داوری محمدابراهیم فاضلی

one of the important aspects of soil is, knowing the relationships between spatial features of soil and quantity in statistical model. the goal of this research is to estimate saturated hydraulic conductivity by regression and co-active neuro-fuzzy inference system (anfis) with using the parameters of bulk density, real density, porosity, fractal dimension of particle size, and clay percent, si...

Journal: :تحقیقات مهندسی کشاورزی 0
بهزاد قنبریان علویجه دانشجوی دکتری دانشکده آب و خاک پردیس کشاورزی و منابع طبیعی دانشگاه تهران عبدالمجید لیاقت دانشیار گروه آبیاری و آبادانی دانشکده آب و خاک پردیس کشاورزی و منابع طبیعی دانشگاه تهران سمانه سهرابی دانشجوی کارشناسی ارشد گروه مهندسی آب دانشکده کشاورزی دانشگاه تبریز

soil hydraulic properties such as saturated and unsaturated hydraulic conductivity play an important role in environmental research. since direct measurement of these soil hydraulic properties is time-consuming and costly, indirect methods such as pedotransfer functions and artificial neural networks (ann) were developed based on readily available parameters. in this study, the use of ann to pr...

ژورنال: علوم آب و خاک 2015
مصدقی, محمد‌رضا , همت, عباس , ویسی‌تبار, عالیه ,

Considering soil compaction problem in sugarcane fields due to using heavy harvester and haulout equipment under unsuitable moisture conditions, this research aims to assess soil compaction in sugarcane fields located in Da'balKhazaei Plantation unitofSugarcane Development and By-product Company, Ahvaz. Undisturbed soil samples from the furrow (wheel tracks) were collected for measuring soil wa...

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