The pedogenesis of desert loam soils in the Barrier Range, western New South Wales. Ii. Weathering and soil formation

Soil Research ◽  
1983 ◽  
Vol 21 (1) ◽  
pp. 1 ◽  
Author(s):  
CJ Chartres
Keyword(s):  
Calcium Carbonate ◽  
Soil Structure ◽  
New South ◽  
Soil Formation ◽  
Middle Layer ◽  
Soluble Salts ◽  
Aeolian Deposits ◽  
South Wales ◽  
Pedogenetic Processes

Micromorphological, clay mineralogical and chemical data are used to demonstrate the complex, polygenetic nature of soils developed in a mixture of aeolian deposits and in-situ weathered material. At least three separate layers can be recognized in the soils, though some pedological reorganization of these has occurred. The lowest layer consists of weathered rock, aeolian deposits, gypsum and calcium carbonate, and may be, in part, the truncated remnant of an older soil. The middle layer is predominantly composed of aeolian clayey pellets and silts. The upper layer is a slope-wash deposit. The majority of soluble salts, carbonates and sulfates in the soils appear to have been transported into the soils by wind. Pedogenetic processes after the last phase of aeolian deposition have been restricted to the redistribution of some of the more soluble salts and iron oxides, and the modification of soil structure and fabric.

A grower survey of rotations used in the New South Wales cotton industry

1999 ◽  
Vol 39 (6) ◽  
pp. 743 ◽  
Author(s):  
J. L. Cooper
Keyword(s):  
Soil Structure ◽  
New South ◽  
New South Wales ◽  
Cotton Industry ◽  
Rotation System ◽  
System A ◽  
South Wales ◽  
Rotation Crops ◽  
Grower Survey ◽  
Rotation Crop

Summary. Cotton growers in the Macquarie, Namoi and Gwydir Valleys of New South Wales were surveyed in 1992 to determine what crops are grown in rotation with cotton, how frequently rotation crops are used, and what influences the grower’s choice of rotation system. A total of 155 properties were surveyed, covering 100, 49 and 58% of irrigated cotton produced in the Macquarie, Namoi and Gwydir Valleys, respectively. Although a large part of the 1992–93 cotton crop (61% by area) did not follow a rotation crop, there was widespread interest in rotations and 70% of properties had used rotations. Wheat was by far the most widely grown rotation crop, but there was considerable interest in other crops, especially legumes. The perceived benefits from rotation crops reported by most growers were better soil structure, less disease in following cotton, and more soil organic matter. However, when asked why they preferred certain rotation crops, these factors did not rate highly with growers. Crops that were easy to grow and gave the best financial returns possessed the main features sought in a rotation crop. The greatest problem in growing rotation crops was a lack of irrigation water. It is not surprising that this problem ranked highly because when the survey was conducted, the Namoi and Gwydir Valleys had water allocations of 15 and 0%, respectively. Not having suitable equipment to sow rotation crops was also a problem for 17% of growers, but 10% encountered no problems. The survey also investigated the use of permanent beds and retained hills. These practices have benefits for soil structure, and are almost essential for rotation crops which need to be sown as soon as the cotton is harvested. Over 80% of growers using rotations had adopted some form of permanent beds or retained hills. The benefit which ranked highest was a reduction in costs, followed by less soil compaction. Some growers (44%) who used permanent beds or retained hills had no problems, but handling the trash and keeping the rows straight were of concern to others.

Evidence of High Sea Level during Isotope Stage 5c in Queensland, Australia

1985 ◽  
Vol 24 (1) ◽  
pp. 103-114 ◽  
Author(s):  
J. W. Pickett ◽  
C. H. Thompson ◽  
R. A. Kelley ◽  
D. Roman
Keyword(s):  
Sea Level ◽  
New South ◽  
Good Condition ◽  
Coastal Dunes ◽  
Intertidal Sediments ◽  
South Wales ◽  
Eastern Australia ◽  
Maximum Period ◽  
High Dune

Thirty-nine species of scleractinian corals have been recovered from under a high dune on the western (mainland) side of North Stradbroke Island, eastern Australia. The corals are associated with thin intertidal sediments and their good condition implies burial in situ and preservation in a saturated zone. Most likely this occurred as the coast prograded and a large dune advanced into the littoral zone, burying intertidal sediments and coral. The species assemblage indicates a sheltered environment but one open to the ocean without wide fluctuations in salinity. Three species yielded a mean 230Th/234U age of 105,000 yr B.P. which is significantly younger than the nearest Pleistocene corals at Evans Head, New South Wales. The corals provide evidence of a sea stand near present sea level during isotope Stage 5c, which is considerably higher than previously suggested for this period. Their good condition implies that the overlying parabolic dune is of comparable age and formed during that high stand of sea level. Also, the isotope age provides a maximum period for the development of giant podzols in the podzol chronosequences on coastal dunes in southern Queensland.

Field measurements of nitrogenase activity in soils amended with wheat straw

1983 ◽  
Vol 34 (6) ◽  
pp. 725 ◽  
Author(s):  
MM Roper
Keyword(s):  
Nitrogenase Activity ◽  
New South ◽  
Field Measurements ◽  
Field Capacity ◽  
Nitrogen Fertilizers ◽  
Free Living ◽  
Straw Decomposition ◽  
Indirect Measure ◽  
South Wales

Nitrogenase activity and decomposition of straw were examined in situ in two areas (Gunnedah and Cowra) representative of large areas of the New South Wales wheat belt. Measurements of nitrogenase activity were made by adapting the acetylene reduction assay for use in the field. Evolution of CO2 was monitored as an indirect measure of decomposition of straw. The addition of straw to soil stimulated nitrogenase activity which was related to the amount of straw added and the rate of straw decomposition. There were significant levels of activity provided the soil was moist and warm. Nitrogenase activity increased with mean daily soil temperature (up to at least 30�C) and decreased as the soil dried from field capacity. It is concluded that nitrogen fixation by free-living nitrogen-fixing microorganisms in soils amended with straw may contribute to the nitrogen status of the soil and thus reduce the need for nitrogen fertilizers.

scholarly journals The Pattern of In Situ Stress in Onshore Basins of New South Wales

2015 ◽  
Author(s):  
Mojtaba Rajabi* ◽  
Mark Tingay ◽  
Oliver Heidbach ◽  
Rosalind C. King
Keyword(s):  
New South ◽  
New South Wales ◽  
In Situ Stress ◽  
South Wales

Bacterial in situ-reproduction and colonization of sediments occurring in a limestone mine

2021 ◽  
Author(s):  
Claudio Zaccone ◽  
Edoardo Puglisi ◽  
Fabio Terribile ◽  
Andrea Squartini
Keyword(s):  
Calcium Carbonate ◽  
Clay Minerals ◽  
Inductively Coupled Plasma ◽  
High Throughput Sequencing ◽  
Pcr Amplification ◽  
Ground Level ◽  
Middle Layer ◽  
Bottom Layer ◽  
Sequencing Analysis

<p>A 3-m thick sediment was found in a limestone mine located in the southern part of the Gargano Promontory, Apulia region (south of Italy), at a depth of ca. 25-30 m from the current ground level.</p><p>Samples from 5 layers were analysed by X-ray diffraction (XRD), elementar analysis (CHNS), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Microbial DNA was also extracted and bacterial diversity analysed by PCR amplification and Illumina High-Throughput Sequencing (HTS) of the V3-V4 hypervariable regions of 16S rRNA.</p><p>Preliminary data showed that these sediments formed by subsequent weathering of carbonates and silicates, either by in situ oxidation or by dissolution followed by migration and reprecipitation, rather than during the accumulation of shallow marine sediments occurring between the middle Pliocene and the lower Pleistocene, when the extreme western sectors of the Apulian foreland underwent strong subsidence.</p><p>The main mineral compounds occurring in the 5 layers, from the top to the bottom, were the following: calcite (80%) and clay minerals in sample #1, goethite (75%) and hematite in sample #2, manganese (66%) and iron oxides in sample #3, almost exclusively goethite in sample #4, and calcite (71%) and clay minerals in sample #5.</p><p>From the microbiological point of view, drawn from a 16S metabarcoding amplicons sequencing analysis, these 5 layers appear to cluster in three groups: a) the uppermost layer (sample #1), dominated by a single and abundant taxon of Arthrobacter sp., which includes species known for  the capability of calcite precipitation; b) a middle layer (including samples #2 and #3), without prevailing abundances and less consistent occurrences across replicates, which featured members of the Oxalobacteraceae family and of the Methylophilus genus. Their closest matches in Genbank subjects included isolates from habitats such as calcium carbonate (moonmilk) muds in percolating waters within caves, mine tailings and other groundwater microcosms; c) a bottom layer (samples #4 and #5), showing an oligarchic situation and high abundances of bacteria but different from the ones that prevailed in the top layer and including members of the Nocardioidacaeae family. Also for these sequence queries, the closest GenBank subjects include cases with calcium carbonate-precipitating capabilities isolated from cave and groundwater sediments or former mining sites in studies on iron oxidizers in creek sediments at pH 4.4 or at high heavy metal concentrations.</p><p>Overall, such a distribution suggests that, both in the top and bottom layer, different communities would have undergone in situ-reproduction and colonization exploiting metabolically the substrate, whereas the mid layers would have received bacterial convection by passive transport of percolating waters.</p>

The pedogenesis of desert loam soils in the Barrier Range, western New South Wales. I. Soil parent materials

Soil Research ◽  
1982 ◽  
Vol 20 (4) ◽  
pp. 269 ◽  
Author(s):  
C.J. Chartres
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Saline Lake ◽  
New South ◽  
Morphological Properties ◽  
Parent Materials ◽  
Rock Types ◽  
Aeolian Deposits ◽  
South Wales ◽  
Mineral Assemblages

The particle-size distribution, silt (63-20 �m) mineralogy and micro-morphological properties of three desert loam soils developed over contrasting rock types are examined. The silt mineral assemblages in the soils contain more weatherable minerals and are more varied than those of the underlying rocks. Round to subround clayey pellets constitute the majority of the soil materials. Such pellets are probably aeolian in origin and are similar to clayey pellets originating in dried-out, saline lake beds elsewhere in southern Australia. The combination of aeolian silts and clays in the desert loam soils indicate that the soil parent materials are primarily transported aeolian deposits.

Carbon inputs by wheat and vetch roots to an irrigated Vertosol

Soil Research ◽  
2012 ◽  
Vol 50 (3) ◽  
pp. 177 ◽  
Author(s):  
N. R. Hulugalle ◽  
T. B. Weaver ◽  
L. A. Finlay
Keyword(s):  
Unit Area ◽  
New South ◽  
Farming Systems ◽  
Triticum Aestivum L ◽  
Root Mortality ◽  
Root Carbon ◽  
South Wales ◽  
Wheat Stubble ◽  
Experimental Treatments

Research on the amounts of carbon that can be added to Vertosols of New South Wales and Queensland by crop roots in irrigated cotton farming systems is sparse. The objective of this study was to determine the amounts of carbon added to soil by roots of wheat (Triticum aestivum L.) and purple vetch (Vicia benghalensis L.) sown in rotation with irrigated cotton (Gossypium hirsutum L.). Measurements were made from 2008 to 2010 in an ongoing experiment near Narrabri, northern NSW, using a combination of soil cores and minirhizotron observations. The experimental treatments were: cotton monoculture; cotton–vetch (CV); cotton–wheat, in which wheat stubble was incorporated into the beds with a disc-hiller (CW); and cotton–wheat–vetch, in which wheat stubble was retained as in-situ mulch (CWV). Vetch was killed by a combination of mowing and contact herbicides, and the residues were retained as in situ mulch. Root length per unit area of vetch in CWV and wheat in both CW and CWV was comparable, although wheat had a higher concentration of roots in surface 0.10 m. Root growth of the CV treatment was sparse. Root carbon available for addition to soil was greater with vetch than with wheat and was in the order: vetch in CWV (5.1 t C/ha.year) > vetch in CV (1.9 t C/ha.year) > wheat in CW (1.6 t C/ha.year) = wheat in CWV (1.7 t C/ha.year). Intra-seasonal root mortality accounted for 12% of total root carbon in vetch and 36% in wheat. The remaining fraction consisted of carbon in the root mass at the end of the growing season. Carbon sequestered by root inputs of the rotation crops was estimated to be ~0.34 t C/ha.year for the vetch and wheat crops in the CWV rotation, 0.10 t C/ha.year for vetch in CV, and 0.08 t C/ha.year for wheat in CW. Rotation CWV was, therefore, the most effective in sequestering carbon from roots.

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