Laboratory Consolidation of Some Normally Consolidated Soils

1966 ◽  
Vol 3 (4) ◽  
pp. 217-234 ◽  
Author(s):  
Gerald Patrick Raymond
Keyword(s):  
New South ◽  
New South Wales ◽  
Complete Agreement ◽  
Soil Parameters ◽  
Standard Laboratory ◽  
Load Increment ◽  
Large Load ◽  
Hydrostatic Loading ◽  
South Wales ◽  
Triaxial Cell

A theory of consolidation is developed assuming:[Formula: see text]Solutions are given for the case of a thin bed of clay subjected to an instantaneous load increment. It is shown how the soil parameters may be obtained from standard laboratory consolidation tests. It is intended to discuss the application of the theory to field cases in a later paper.One-dimensional drainage tests performed in both the oedometer and triaxial cell are presented. The tests in the triaxial cell were performed using hydrostatic loading. The laboratory work was conducted on some remoulded New South Wales soils, some artificially deposited North American soils, and some undisturbed Ontario soils using instantaneous loading and large load ratios. Discussion is mainly illustrated with the tests performed on the artificially deposited soils.The propounded theory was found to be in reasonable but not complete agreement with the test results.D'Arcy's law was found to be valid for the soils tested.

Some investigations into soil and vegetation relationships associated with alkaline-saline soil surfaces in the Walcha area, Northern Tablelands, New South Wales

1995 ◽  
Vol 46 (1) ◽  
pp. 209 ◽  
Author(s):  
KH Kreeb ◽  
RDB Whalley ◽  
JL Charley
Keyword(s):  
Cynodon Dactylon ◽  
New South ◽  
New South Wales ◽  
Soil Surface ◽  
Tree Planting ◽  
Soil Parameters ◽  
Alkali Cations ◽  
Grazing Land ◽  
South Wales ◽  
Wide Range

The characteristics of the soil, vegetation and groundwater at a dryland salinity site on Miramoona, a property near Walcha on the Northern Tablelands of New South Wales, were investigated. Soil parameters measured at 23 points along a 200 m transect were highly correlated with the pattern of vegetation. Of overriding significance was soil pH, which varied from a high of over 10 on bare areas delineated by Critesion marinum and Cynodon dactylon to a low of less than 5 on grazing land supporting the growth of a wide range of pasture species. The bare areas were characterized by alkalinity. While they were sodic at all depths measured, they were only marginally saline and then only at the soil surface. The chemical composition of the groundwater collected from three piezometer tubes varied quite markedly over the site. It is hypothesized that the presence of alkaline bare areas on the Northern Tablelands is not a new problem, but rather the natural result of alternating wet and dry periods which have induced accumulation of carbonates and bicarbonates of the alkali cations, notably sodium. Drainage of the original perched swamps by the early landholders, tree clearing and the grazing of domestic livestock would have accelerated the process since European settlement. However, tree planting would appear unlikely to have any impact on the reclamation process in the short term. A more viable option would be the recreation of the original swamps in suitable situations, although this solution would create problems for grazing management.

Factors contributing to the acid sulfate soil scalding process in the coastal floodplains of New South Wales, Australia

Soil Research ◽  
2004 ◽  
Vol 42 (6) ◽  
pp. 587 ◽  
Author(s):  
Mark A. Rosicky ◽  
Leigh A. Sullivan ◽  
Peter G. Slavich ◽  
Mike Hughes
Keyword(s):  
New South ◽  
New South Wales ◽  
Pyrite Oxidation ◽  
Soil Surface ◽  
Soil Parameters ◽  
Soil Core ◽  
Acid Sulfate Soil ◽  
Vegetative Cover ◽  
Acid Sulfate ◽  
South Wales

Acid sulfate soil (ASS) scalds are persistently bare areas of land, occurring in the coastal backswamps of New South Wales (NSW), Australia. This study aims to understand why particular areas become ASS scalds, while adjacent areas remain vegetated. Some important soil parameters are compared and field observations are summarised. Soil core sampling in both ASS-scalded land and surrounding areas of permanently vegetated paddocks has demonstrated similar pyrite concentrations and depth occurrence, soil salinity, and soil acidity (pH). As conditions are similar beneath both vegetated and non-vegetated land, there must be some additional factors influencing which areas become denuded. Several disparate (usually human-induced) events were found to cause initial loss of vegetative cover. Once the soil is bare, surface evaporation causes toxic solutes to build up quickly at the soil surface and ASS scalding is perpetuated. Some of the intervening events include fire, flood, flood-scouring, deliberate topsoil removal, surface pyrite oxidation, saltwater inundation of freshwater paddocks, saltwater exclusion from saltmarsh or mangroves, changes to the vegetation regimes, excessive vehicular traffic, and over-grazing. Backswamp management needs to ensure that land underlain by shallow pyritic layers (or with soil-water that is enriched with the toxic by-products of pyrite oxidation) is not laid bare by accident or design. Similar soil chemical conditions underlying both ASS scalds and the surrounding permanently vegetated paddocks suggest that much larger areas are potentially at risk of ASS scalding.

Land-use effects on soil properties on the north-western slopes of New South Wales: Implications for soil condition assessment

Soil Research ◽  
2008 ◽  
Vol 46 (4) ◽  
pp. 359 ◽  
Author(s):  
B. R. Wilson ◽  
Ivor Growns ◽  
J. Lemon
Keyword(s):  
Land Use ◽  
Bulk Density ◽  
New South ◽  
New South Wales ◽  
Soil Condition ◽  
Soil Parameters ◽  
Land Uses ◽  
Soil C ◽  
The North ◽  
South Wales

In Australia, as elsewhere, there is a growing need for information relating to soil condition, its current status, and the nature and direction of change in response to management pressures. This information is required by land managers, and regional, State and, national agencies to inform modified land-use practices and investment to maintain and improve the soil resource. Here, we present data relating to soils under 3 land-use types at 6 properties the north-western slopes of New South Wales. We aimed to quantify the range of soil condition states that exist across the region and to test a range of potential soil condition indicators and their suitability to detect differences in soil condition between these land-use types. A range of soil properties showed no significant difference between land-uses and could be rejected as indicators. However, significant differences existed between the land-uses and soil depths for a range of the other soil parameters determined (bulk density, C, N, P, EC, and Na). Soil C, N, P, and Na concentration and total soil C were typically higher in woodland soils compared with other land-uses, while bulk density, pH, and EC were lower in the woodland soils. The depth at which these differences existed varied between soil parameters. Correlation and principal components analysis suggested that a minimum dataset of soil parameters including soil bulk density, pH, C, P, and Na would discern much of the difference in soil condition between the land-uses studied. It is proposed that these parameters be used as a minimum dataset of indicators for soil condition assessment on soils of the type across this region. Work continues under the New South Wales Land and Soil Condition Monitoring Program to further refine the selection of appropriate soil indicators in this and other regions of New South Wales.

The influence of individual native trees and grazing regime on soil properties and groundcover patterns in a temperate landscape of New South Wales, Australia

2009 ◽  
Vol 31 (4) ◽  
pp. 405 ◽  
Author(s):  
Phoebe Barnes ◽  
Brian R. Wilson ◽  
Chris Nadolny ◽  
Ivor Growns
Keyword(s):  
Agricultural Landscape ◽  
New South ◽  
New South Wales ◽  
Tree Canopy ◽  
Soil Parameters ◽  
Agricultural Activity ◽  
Vegetation Composition ◽  
Soil C ◽  
Native Trees ◽  
South Wales

Scattered native trees are a significant ecological resource across the agricultural landscape, yet their numbers are declining due to factors such as dieback, senescence and agricultural activity. This study examined the interactions among Eucalyptus melliodora (Cunn. ex Schauer) trees, vegetation composition and selected surface soil chemical properties in grazed and ungrazed paddocks on the Northern Tablelands of New South Wales, Australia. Four farms on granite soils were examined in grazed and ungrazed treatments. Vegetation composition was assessed, and soil samples were collected in plots beneath the canopy and in adjacent open areas in both north and south directions of the tree canopy. Native grasses dominated the vegetation in both beneath the canopy and open areas, at both grazed and ungrazed sites. However, their composition varied between farms. Several C3 and C4 grasses contributed to the groundcover of the canopy and open sites, but C3 grasses were generally more common under the canopy. Significant differences occurred in soil C, N, P and pH, and vegetation composition between canopy and open areas, and between grazed and ungrazed treatments. Soil P, C and N contents in grazed sites were typically similar to or higher than those in ungrazed sites, and soils were less acid in the ungrazed compared with grazed sites. All soil parameters measured were significantly higher under tree canopies, except P. The tree, soil and vegetation factors were strongly related. This study confirms that individual scattered trees create a distinct mosaic of localised soil improvement, and influence vegetation composition so that paddocks with trees are floristically more diverse than paddocks without trees. The results illustrate the potential benefits of retaining trees for both biodiversity values and livestock production in Australia.

Techniques for revegetation of acid sulfate soil scalds in the coastal floodplains of New South Wales, Australia: ridging, mulching and liming in the absence of stock grazing

2006 ◽  
Vol 46 (12) ◽  
pp. 1589 ◽  
Author(s):  
M. A. Rosicky ◽  
P. Slavich ◽  
L. A. Sullivan ◽  
M. Hughes
Keyword(s):  
Soil Moisture ◽  
Root Zone ◽  
New South ◽  
Combined Treatment ◽  
New South Wales ◽  
Soil Parameters ◽  
Acid Sulfate Soil ◽  
Acid Sulfate ◽  
South Wales ◽  
Vegetation Species

Two revegetation field trials were undertaken on chronically bare acid sulfate soil scalds on grazing properties in the Hawkesbury and Macleay catchments of New South Wales, Australia. The aim was to test the effectiveness of various low cost and readily accessible techniques to encourage revegetation (via existing seedbank or surrounding vegetation) of the scalded sites. The trial at the more efficiently drained Hawkesbury site used a combined treatment of ridging (R), mulching (M) and liming (L) (i.e. R–M–L) compared with a control, within a fenced area. At the more waterlogged Macleay site, various elements of the combined treatment (i.e. R, M, R–M, R–L, R–M–L) were compared with a control, within a fenced area. Vegetation occurrence, biomass and species were tested, along with pertinent soil parameters (pH, salinity, soil moisture, soluble metals). Soil testing was undertaken at 2 depth levels to represent the seed germination zone (0–1 cm), and the potential root zone (1–10 cm). At the Hawkesbury site, the combined treatment (R–M–L) caused significantly greater vegetation occurrence and biomass, lower salinity, higher pH and increased soil moisture. At the Macleay site, results were more variable, but similar to the Hawkesbury trial as the site dried out. Mulching was the single most important treatment. All mulched sites had significantly more vegetation than the control, reaching 100% coverage in the R–M–L plots. Stock exclusion alone produced minimal results. Ridging alone was counterproductive. Liming without mulching caused proliferation of an insubstantial and transient vegetation species (Isolepis inundata). Most interesting was the different vegetation species encouraged by the different mulch treatments: treatment M was dominated by the sedge, Eleocharis acuta; treatment R–M was an even mix of Eleocharis acuta and native water-tolerant grasses (Paspalum distichum and Pseudoraphis paradoxa); treatment R–M–L was dominated by the aforementioned native grasses. These grasses are highly favoured for both economic (highly palatable to stock) and environmental (thick mulch cover, self seeding) objectives. The results demonstrate that revegetation of acid sulfate soil scalds is possible, and different treatments can influence vegetation species composition.

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