نتایج جستجو برای: soil compaction p 0001

تعداد نتایج: 1446986  

Journal: :جنگل و فرآورده های چوب 0
فاطمه موسوی دانشجوی کارشناسی ارشد مهندسی جنگل، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران احسان عبدی دانشیار دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران علی رئیسی استبرق استادیار گروه مهندسی آبادانی و آبیاری، دانشگاه تهران، کرج، ایران باریس مجنونیان استاد دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران

stabilization, alter and improvement of engineering properties of soil are for providing predetermined goals. the most important aim of soil stabilization is increasing long term soil strength, but in very wet and loos lands the other aim of soil stabilization, is to decrease plasticity characteristic of soil, which are tested by atterberg limits tests. since the road soils of namkhane district...

Journal: :Journal of environmental quality 2009
John T Walker James M Vose Jennifer Knoepp Christopher D Geron

Establishment of riparian buffers is an effective method for reducing nutrient input to streams. However, the underlying biogeochemical processes are not fully understood. The objective of this 4-yr study was to examine the effects of riparian zone restoration on soil N cycling mechanisms in a mountain pasture previously degraded by cattle. Soil inorganic N pools, fluxes, and transformation mec...

2006
Tairone Paiva Leão Álvaro Pires da Silva

Measurements of soil penetration resistance (SR) have been frequently used for the evaluation of soil structural quality for plant growth. However, different data analysis approaches have been used, without a previous evaluation of their statistical quality. In this study we tested the hypothesis that the mean is the parameter with best statistical properties to evaluate alterations in soil pen...

1999
Bruce C. Ball Albert Scott John P. Parker

Tillage practices and weather affect the release of greenhouse gases but there have been few integrated studies of the quantities released or the mechanisms involved. No-tillage may increase emissions of nitrous oxide (N2O) and the ®xation of carbon by decreasing carbon dioxide (CO2) emissions. Tillage may also decrease the oxidation rate of atmospheric methane (CH4) in aerobic soil. These effe...

2016
Julian J. Zemke

Forestry operations can significantly alter hydrological and erosional processes in a catchment. In the course of developing timberland, a network of persistent roads and skid trails causing soil compaction is usually established. Hereby, the infiltration rate of the soil is distinctly reduced, which leads to the generation of overland flow—this may also cause soil erosion. In this study, a sma...

2006
Graeme Hope

A clear understanding of the impacts of forest practices on long-term soil productivity is required to maintain the productivity of forest soils while forests continue to be managed for timber production. Although current regulations governing soil conservation in British Columbia are partially based on historic and ongoing research, there are few clear and unambiguous long-term results. The ne...

2000
Charles H. Walkinshaw Allan E. Tiarks

Root studies are being used to monftor possible changes in growth of loblolly pines on a long-term serf productivity study site. Here, we report the results of a preliminary look at roots in the sixth growrng season, Roots were collected from loblolly pines grown in soil that was first subjected to three levels of compaction (none, moderate, severe) and three levels of organic matter removal (s...

ژورنال: علوم آب و خاک 2010
افیونی, مجید, شیرانی, حسین , حاج عباسی, محمدعلی , همت, عباس,

Tillage systems and organic manures could affect soil physical and mechanical properties. This study was conducted to investigate the impacts of two tillage systems including conventional tillage by moldboard plowing (plowing depth, 30 cm) and reduced tillage by disk plow (plowing depth, 15 cm) and three rates (0, 30 and 60 ton ha-1) of farmyard manure (FYM) on the soil penetration resistance u...

Journal: :تحقیقات آب و خاک ایران 0
مژده لاهوری پردیس کشاورزی و منابع طبیعی دانشگاه تهران محمود بابالار دانشکده کشاورزی و منابع طبیعی دانشگاه تهران علی رئیسی استبرق university of tehran صادق رنجبری پردیس کشاورزی و منابع طبیعی دانشگاه تهران

in this research the effect of randomly reinforced soil and soil cement with different percent of cement and fiber and different length of fiber was investigated. samples were prepared according to the maximum dry unit weight and optimum water content due to the corresponding compaction curves. compressive and tensile strength were conducted on samples for different curing times. regression equ...

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