نتایج جستجو برای: total soil porosity
تعداد نتایج: 978352 فیلتر نتایج به سال:
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...
Skidding by means of heavy forestry machinery can affect soil physical properties. We assessed the effects of ground based skidding on soil bulk density and total porosity under the Iranian mountainous forest conditions. Treatments included a combination of four levels of traffic intensity (1, 3, 6, and 15 passes) of a Timberjack 450C rubber skidder and two levels of slope (<20% and >20%). The ...
dispersivity (?) and effective transport porosity (?eff) are input parameters in equilibrium convection dispersion equation (cde). normally these parameters are obtained from breakthrough curves by inverse method. however, obtaining breakthrough curves in the field is not often possible in practice. the objective of this study was to estimate ? and feff from soil hydraulic data. for this purpos...
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 ( ...
In this study the impact of production work on the skid roads that have been carried out for many years by manpower animal power or machinery in a beech (Fagus orientalis Lipsky) stand have been examined. For this purpose, herbaceous understory, forest floor and soil samples were collected from the undisturbed area and the skid road. Weight per unit area (kg ha(-1)), organic matter ratio and mo...
In present work, we studied the ecological-hydrological law of three manmade forest communities at a located site of the central Yunnan province from 1998 to 2000. The finding indicated that the interception of canopy, stem-flow, through-fall of E.maideni-A.mearnsii, E.maideni, P.Yunnanensis took respectively up 35.21%, 0.65%, 64.14%; 30.10%, 0.88%, 67.56%; 27.8%, 4.64%, 69.25% of total precipi...
The present work aimed to contribute for a better knowledge regarding soil features as cork quality indicators for stoppers. Cork sampling was made in eight Cork oak stands (montados de sobreiro) located in the Plio-Plistocene sedimentary formations of Península de Setúbal in southern Tagus River region. The samples used to classify the cork as stopper for wine bottles were obtained in eight co...
improvement of soil properties through sustainable agriculture requires suitable management of plant residues. this study was conducted to investigate the effect of different types and managements of plant residue on soil physical properties in a field experiment as factorial based on rcbd with three replicates. the first factor was residue type including barley straw and alfalfa residue, and t...
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...
Sub-surface irrigation (SUI) is a new water-saving irrigation technology. To explore the influence of SUI on soil conditions in a cherry orchard and its water-saving efficiency, experiments were conducted from 2009 to 2010 using both SUI and flood irrigation (FLI) and different SUI quotas in hilly semi-arid area of northern China. The results demonstrated the following: 1) The bulk density of t...
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