نتایج جستجو برای: soil porosity

تعداد نتایج: 197471  

2008
Shufang Jiang Yaohu Kang Zeqiang Sun

Measurements of porosity and pore size distribution provide important data on the physical properties of soils. This paper presents a digital image method for the analysis of soil pores. In the analysis of soil thin sections, the image threshold separating pore space from the surrounding solid, as well as the capillary pore size threshold separating air pores and capillary pores, was obtained b...

2000
Y. Pons

In clayey, swelling and more or less sodic soils, cultivation and seasonal climatic cycles induce variations in soil moisture which in turn cause variations in the soil structure. In particular, when the soil profile is saturated, some soils become impermeable because the soil porosity value does not remain sufficiently high throughout the drainage period to be effective for water movement. In ...

1999
Klaudia Oleschko

Self-similar fractals are useful models of the soil solid and pore sets along lines, across areas and inside volumes. The scaling properties of these sets, analysed by the divider method within the known scale range over which the fractal extends, were described by three parameters, the solid (Ds) and pore (Dp) linear box or capacity empirical fractal dimensions, and the total number of rulers ...

2014
Ramin Naghdi Ahmad Solgi

Skidding operations induce changes in soil physical properties, which have the potential to impact soil sustainability and forest productivity. Our objective was to investigate the effects of traffic frequency, trail slope, and soil moisture content on soil compaction, total porosity and rut depth. Treatments included a combination of three different traffic intensities (3, 7, and 14 passes), t...

Journal: :Science 2000
R M Iverson M E Reid N R Iverson R G LaHusen M Logan J E Mann D L Brien

Some landslides move imperceptibly downslope, whereas others accelerate catastrophically. Experimental landslides triggered by rising pore water pressure moved at sharply contrasting rates due to small differences in initial porosity. Wet sandy soil with porosity of about 0.5 contracted during slope failure, partially liquefied, and accelerated within 1 second to speeds over 1 meter per second....

2007
Geraldo C. Oliveira Eduardo C. Severiano Carlos R. Mello

This study aims to evaluate soil moisture and bulk density effects on penetration resistance dynamics of Dark Red Latosol, located in the Microregion of Goiânia, Goias. Area under rotating pasture were sampled 1) in lines and 2) between lines; 3) pasture renewal area; 4) area under Central Pivot; 5) area under no-tillage and 6) forest. Penetrometry tests were done for three different soil moist...

Journal: :آب و خاک 0
سهیلا سید دراجی احمد گلچین شروین احمدی

abstract agriculture is the largest consumer of water resources in iran. one of the best options for increasing the irrigation efficiency and better application of precipitation in arid and semi-arid areas is employing of superabsorbent polymers to soil. polymers can absorb rain and irrigation water, decrease deep percolation and increase water use efficiency. in order to investigate the effect...

Journal: :SIAM Journal of Applied Mathematics 2010
Mariya Ptashnyk Tiina Roose

Abstract. In this paper we derive a model for the diffusion of strongly sorbed solutes in soil taking into account diffusion within both the soil fluid phase and the soil particles. The model takes into account the effect of solutes being bound to soil particle surfaces by a reversible nonlinear reaction. Effective macroscale equations for the solute movement in the soil are derived using homog...

2010
Yu Guo Han Pei Ling Yang Yuan Pei Luo Shu Mei Ren Li Xia Zhang Lei Xu

Drought is a great concern in agricultural production, because it restricts normal plant growth, brings about enormous economic loss and deteriorates ecological environment. Proper use of super absorbent polymers (SAP) is helpful in the agricultural and horticultural industry in arid and semi-arid areas, because SAP can ease the burden of water shortage. Because porosity is one of the most impo...

2006
A. Eynard

Soil wettability is especially important for rainfed agriculture in climates with a dry period during the growing season. The effect of aggregate structure and soil organic C content on wettability of soil aggregates was determined for grassland (grass) and tilled fields (tillage). Soil organic C, plastic limit, aggregate total porosity, and wettability at 100 mm (rapid wetting) and 300 mm (slo...

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