SOIL HYDRAULIC PROPERTIES DETERMINED WITH WATER AND WITH A HYDROCARBON LIQUID

1970 ◽  
Vol 50 (1) ◽  
pp. 79-84 ◽  
Author(s):  
J. C. VAN SCHAIK
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Relative Permeability ◽  
Hydraulic Properties ◽  
Direct Transfer ◽  
Soil Hydraulic Properties ◽  
Distribution Index ◽  
Wetting Fluid ◽  
Hydrocarbon Oil

Hydraulic properties of three soils were compared using either water or a hydrocarbon oil as the wetting fluid. Equations relating various properties for oil were also valid for water when appropriate values for water were used. As differences in saturated permeability were not consistent, a direct transfer of data obtained with oil to those of water was not possible. The relative permeability for both fluids showed better agreement because bubbling pressures were similar. However, the pore-size distribution index for water was somewhat lower than that for oil.

SOIL HYDRAULIC PROPERTIES AFFECTED BY SATURATION TECHNIQUE

1969 ◽  
Vol 49 (1) ◽  
pp. 95-102 ◽  
Author(s):  
J. C. van Schaik ◽  
G. E. Laliberte
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Atmospheric Pressure ◽  
Hydraulic Properties ◽  
Test Fluid ◽  
Soil Hydraulic Properties ◽  
Vacuum Saturation ◽  
Distribution Index ◽  
Entrapped Air

Properties characterizing the hydraulic behavior of three soils were determined from drainage cycle tests using samples wetted with core test fluid by three saturation techniques: saturation under vacuum, saturation from below at atmospheric pressure and saturation from above at atmospheric pressure. Saturated permeability and pore-size distribution index were notably less for samples saturated at atmospheric pressure than for the vacuum-saturated samples. Bubbling pressure and residual saturation, on the other hand, were not affected by saturation technique. The observed dependence of saturated permeability and pore-size distribution index on saturation technique was attributed to the effect of entrapped air. In the modeling of field problems, determining the hydraulic properties of soils wetted at atmospheric pressure is advised.

scholarly journals Hydraulic Properties of Forest Soils with Stagnic Conditions

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1113
Author(s):  
Stefan Julich ◽  
Janis Kreiselmeier ◽  
Simon Scheibler ◽  
Rainer Petzold ◽  
Kai Schwärzel ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Soil Samples ◽  
Stagnant Water ◽  
Infiltration Rates ◽  
Retention Characteristic ◽  
Water Conditions

Tree species, e.g., shallow vs. deep rooting tree species, have a distinct impact on hydrological properties and pore size distribution of soils. In our study, we determined the soil hydrologic properties and pore size distribution at three forest stands and one pasture as reference on soils with stagnant water conditions. All sites are located in the Wermsdorf Forest, where historical studies have demonstrated severe silvicultural problems associated with stagnant water in the soil. The studied stands represent different stages of forest management with a young 25-year-old oak (Sessile Oak (Quercus petraea) and Red oak (Q. robur)) plantation, a 170-year-old oak stand and a 95-year-old Norway Spruce (Picea abies) stand in second rotation. We determined the infiltration rates under saturated and near-saturated conditions with a hood-infiltrometer at the topsoil as well as the saturated hydraulic conductivity and water retention characteristic from undisturbed soil samples taken from the surface and 30 cm depth. We used the bi-modal Kosugi function to calculate the water retention characteristic and applied the normalized Young-Laplace equation to determine the pore size distribution of the soil samples. Our results show that the soils of the old stands have higher amounts of transmission pores, which lead to higher infiltration rates and conductance of water into the subsoil. Moreover, the air capacity under the old oak was highest at the surface and at 30 cm depth. There was also an observable difference between the spruce and oak regarding their contrasting root system architecture. Under the oak, higher hydraulic conductivities and air capacities were observed, which may indicate a higher and wider connected macropore system. Our results confirm other findings that higher infiltration rates due to higher abundance of macropores can be found in older forest stands. Our results also demonstrate that an adapted forest management is important, especially at sites affected by stagnant water conditions. However, more measurements are needed to expand the existing data base of soil hydraulic properties of forest soils in temperate climates.

scholarly journals Carbon sequestration and selected hydraulic characteristics under conservation agriculture and traditional tillage practices in Malawi

Soil Research ◽  
2020 ◽  
Vol 58 (8) ◽  
pp. 759
Author(s):  
Pacsu L. Simwaka ◽  
Eyob H. Tesfamariam ◽  
Amos R. Ngwira ◽  
Paxie W. Chirwa
Keyword(s):  
Organic Carbon ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Particulate Organic Carbon ◽  
Hydraulic Properties ◽  
Conservation Agriculture ◽  
Sub Saharan Africa ◽  
Ecological Zones ◽  
Agro Ecological Zones

Conservation agriculture (CA) is increasingly promoted among smallholder farmers of sub-Saharan Africa in a quest to improve food security while sustaining the natural resource base of the agro-ecosystems where agriculture is based. The aim of this study was to investigate the effects of CA and traditional tillage on soil organic carbon (SOC) and selected hydraulic properties in two contrasting agro-ecological zones of Malawi. Six farmers hosted on-farm trials in each location, with each farmer having the following treatments: CA with continuous sole maize (CA-SM), CA with maize–legume intercrops (CA-ML), and traditional tillage with continuous sole maize (CT-SM). Soil samples were randomly collected in October 2015, from farmers’ fields located in Chipeni, Chinguluwe, Lemu, and Zidyana where CA had been implemented for 10 years (2005–2015) at six depth intervals: 0–10, 10–20, 20–40, 40–60, 60–80, and 80–100 cm. Bulk density, soil water characteristics, and pore size distribution were determined using undisturbed core samples. At all sites, CA improved total SOC, carbon stocks, and the stable fraction of particulate organic carbon. Maize–legume intercropping under CA had 35%, 33%, and 73% more total SOC than CT-SM in Chipeni, Lemu, and Zidyana respectively. In Chinguluwe and Lemu, CA-ML had 0.54 and 0.50 g kg–1 respectively more stable fraction of particulate organic carbon (POMP) than CT-SM; whereas in Chipeni, CA-SM had 0.73 g kg–1 higher POMP compared with CT-SM. CA also improved soil porosity, pore size distribution, and water retention capacity by increasing the proportion of mesopores and micropores compared with CT-SM. Thus, changing management practices from CT-SM to CA has the potential to improve the soil organic matter and soil hydraulic properties across agro-ecological zones in Malawi, which is important for sustainable agriculture. Farmers should be encouraged to minimise tillage, retain residues as mulch on the soil surface, and practice crop rotation.

Investigation of pore size distribution by mercury intrusion porosimetry (MIP) technique applied on different OSB panels

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6661-6668
Author(s):  
Fabiane Salles Ferro ◽  
Felipe Nascimento Arroyo ◽  
Edson Fernando Castanheira Rodrigues ◽  
Iuri Fazolin Fraga ◽  
João Paulo Boff Almeida ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Mercury Intrusion Porosimetry ◽  
Oriented Strand Board ◽  
Promising Result ◽  
Phenolic Resins ◽  
Mercury Intrusion ◽  
Structural Applications ◽  
Wetting Fluid

Mercury intrusion porosimetry (MIP) is a technique used to characterize the pore size distribution and resin penetration in lignocellulosic materials, such as oriented strand board specimens (OSB), a multilayer panel utilized in structural applications. The method is based on the isostatic injection, under very high pressure, of a non-wetting fluid (mercury) into the porous material to determine parameters such as pore size distribution and percentage of porosity of the specimens. In this study, five different OSB were analyzed; they contained different wood species, resin type, and resin content. The panels manufactured with castor oil polyurethane resin showed porosity values in the range of 54.7 and 27.8%. This was a promising result compared with those obtained for panels made with phenolic resins, which are currently commercialized in Brazil.

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