نتایج جستجو برای: soil bulk density

تعداد نتایج: 646486  

Journal: :journal of computational applied mechanics 0
kazem jafari naeimi assistant professor, department of mechanical engineering of biosystems, faculty of agriculture, shahid bahonar university of kerman, kerman, iran hossein baradaran associate professor, department of mechanical engineering, faculty of engineering, shahid bahonar university of kerman, kerman, iran razie ahmadi m.s. student, department of mechanical engineering of biosystems, faculty of agriculture, shahid bahonar university of kerman, kerman, iran malihe shekari m.s. student, department of mechanical engineering of biosystems, faculty of agriculture, shahid bahonar university of kerman, kerman, iran

soil is a nonrenewable source that needs considerable management to prevent physical deteriorationby erosion and compaction. compacted soil causes low fertility and yield. the purpose of this study isto investigate the effect of viscoelastic properties of soil and to determine important factors oncompaction. furthermore, stress distribution, prediction of soil compaction and simulation of its e...

Journal: :مرتع و آبخیزداری 0
مقداد جورغلامی دانشکده منابع طبیعی دانشگاه تهران، دکترای جنگلداری وحید ریزوندی دانشکده منابع طبیعی دانشگاه تهران، کارشناسی ارشد جنگلداری باریس مجنونیان قراقز دانشکده منابع طبیعی دانشگاه تهران، دکترای جنگلداری

assessment and management of the environmental impacts of forest harvesting operations have become increasingly critical factors in practicing commercial forestry. this study investigated soil disturbance from a forest logging system operation on an 8-hectare mixed broadleaved stand in compartment no. 309 in gorazbon district in kheyrud educational and research forest. the objective of this stu...

Journal: :caspian journal of environmental sciences 2010
a. najafi

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 slope...

Journal: :مهندسی زراعی 0

in order to study the effects of sugar cane harvest machinery traffic on bulk density and cone index variation, a survey was conducted in 10 farms of deabel khozaiee sugarcane agro-industrial company, ahvaz, in 2006. in this experiment, two types of harvesters including wheel half track and tire wheels with 14 tons of weight, versus two types of tractor and basket transporters, with 10 and 18 t...

ژورنال: علوم آب و خاک 2011
مهدی همایی, , وحیدرضا جلالی, ,

Soil bulk density measurements are often required as an input parameter for models that predict soil processes. Nonparametric approaches are being used in various fields to estimate continuous variables. One type of the nonparametric lazy learning algorithms, a k-nearest neighbor (k-NN) algorithm was introduced and tested to estimate soil bulk density from other soil properties, including soil ...

A. Najafi, H. Sam Daliri

Skidding operations can cause considerable and wide spread soil disturbance. The objective of this study was to evaluate the effects of ground skidding operations on soil compaction, moisture content, and total porosity at different levels of slope and traffic frequency. Four levels of traffic intensity (3, 8, 13, and >13 passes of a Crawler Tractor Onezhets ? 110) and three levels of slope ( ...

Journal: :پژوهش آب در کشاورزی 0

determination of crops water requirement in different environmental conditions is essential for preparation of precise and suitable irrigation scheduling. the effect of soil compaction and texture on crop coefficient and evapotranspiration of maize was investigated in this study, which was conducted as a factorial experiment with a completely randomized design in a research farm in jey and qaha...

ژورنال: علوم آب و خاک 2014

Water management in cracked paddy soils is an important issue in rice cultivation. In order to study organic matter and zeolite effect and their interaction on moisture conditions and hydraulic and physical properties of paddy soils, the organic matter (rice straw) at four levels (0, 8, 16 and 24 tons per hectare), zeolite at four levels (0, 0.5, 1 and 1.5 percent ), and also moisture stages o...

Journal: :journal of agricultural science and technology 0
i. bogunovic department of general agronomy, faculty of agriculture, university of zagreb, svetosimunska 25, zagreb, croatia. i. kisic department of general agronomy, faculty of agriculture, university of zagreb, svetosimunska 25, zagreb, croatia.

many farmers periodically use deep tillage operations to alleviate compaction in the soil profile caused by natural factors or machinery traffic. in 2012 and 2013, a study was initiated in the pannonian region of croatia to study the effects of no-tillage (nt), conventional tillage (ct) and deep tillage (dt) on soil compaction, measured by (bd), soil water content (swc), penetration resistance ...

Journal: :caspian journal of environmental sciences 2013
a. najafi h. sam daliri

skidding operations can cause considerable and wide spread soil disturbance. the objective of this study was to evaluate the effects of ground skidding operations on soil compaction, moisture content, and total porosity at different levels of slope and traffic frequency. four levels of traffic intensity (3, 8, 13, and >13 passes of a crawler tractor onezhets ? 110) and three levels of slope ( 2...

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