Artykuły w czasopismach na temat „Soils, Salts in – Western Australia”
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1
Biggs, Andrew J. W., i Peter Binns. "Soil morphological and chemical profiles adjacent to a bore drain in south-western Queensland, Australia". Soil Research 53, nr 3 (2015): 325. http://dx.doi.org/10.1071/sr14195.
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A recently abandoned artesian bore drain in south-western Queensland was sampled to investigate soil morphology and chemistry under, and adjacent to, the drain. Such drains are supplied with alkaline, sodium-rich artesian groundwater and they provide a long-term example of the impacts of these waters on soils. A Red Kandosol and a Grey Vertosol were sampled, in the drain and at 2, 4 and 25 m perpendicular to the drain. Morphological attributes indicative of long-term saturation, such as mottling, were evident around the drains, but were absent at the control sites (25 m away). At the Kandosol location, pH and exchangeable sodium were elevated within 4 m of the drain, and salinity data suggested a horizontally displaced wetting front at ~4 m from the drain. In the Grey Vertosol, which was naturally saline and sodic below 0.5 m, substantial leaching of salts had occurred around the drain, but a horizontal wetting front was also evident and exchangeable sodium was increased within 4 m of the drain. A thin, weak pan was detected in the subsoil of the Red Kandosol under the drain bank, but pans were otherwise absent under the drains. The results indicate that deep drainage is a feature not only of the Red Kandosol, but also the Grey Vertosol, despite it being sodic and despite the application of sodic, alkaline water. The findings reiterate the importance of investigating soil and water chemistry interactions when designing channels, storages and irrigation systems, in particular those using sodic–saline waters.
2
Hick, PT, i WGR Russell. "Some spectral considerations for remote sensing of soil salinity". Soil Research 28, nr 3 (1990): 417. http://dx.doi.org/10.1071/sr9900417.
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The National Soil Conservation Program (NSCP) and CSIRO funded a research project titled Remote Sensing of Agricultural Salinity, which gathered field and airborne reflectance data for study sites in areas of dryland agricultural salinity in Western Australia. Multivariate techniques are employed to analyse these data gathered over a 3-year period to determine optimum, spectral and temporal considerations for maximizing information content. This report concentrates on some of the spectral aspects and concludes that: spectral bands, existing in currently available remote sensing systems, may not be optimal for the delineation of salinity; that volunteer vegetation indicated the impact of increasing salinity; and that minor amounts of soluble salts in surface soils will modify spectra. The usefulness of portable field spectroradiometers and airborne scanning systems are also assessed for the discrimination of areas of land in the early stages of the effects of salinization.
3
Cochrane, HR, G. Scholz i AME Vanvreswyk. "Sodic soils in Western Australia". Soil Research 32, nr 3 (1994): 359. http://dx.doi.org/10.1071/sr9940359.
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Sodic soils are common throughout Western Australia, particularly in the south-west agricultural area where they occur mainly as duplex or gradational profiles. Soils with sodic properties are dominant in 26% of the state; saline-sodic sediments and soils in intermittent streams, lakes and estuarine plains occupy a further 5%. Sodic soils are moderately common throughout the south and western portion of the rangeland areas (38% of the state). The south-west coastal sands and the desert and rangeland soils to the north and east of the state are rarely sodic. Although sodicity has been recognized as a discrete problem in W.A. soils since the 1920s, the extent and severity of sodicity has been satisfactorily described only for small areas of the state and most land managers are unaware of the role sodicity plays in limiting the productivity of their soils. Sodicity is implicated in a diversity of problems for both agricultural and non-agricultural uses of Western Australian soils. Subsoil impermeability is probably the most widespread of these, but no comprehensive, quantitative assessment of the influence of exchangeable sodium on subsoil properties has been undertaken. Topsoil sodicity is much less extensive but can severely restrict land productivity, particularly on sandy loam and finer textured soils which set hard when dry. The physical behaviour of Western Australian topsoils cannot usefully be predicted from measurements of exchangeable sodium alone because soils differ so greatly in their response to changing exchangeable sodium. Some remain structurally stable at ESP values >15 while others are so 'sodium-sensitive' that they exhibit highly dispersive behaviour at ESP values as low as 2%. Land values over much of the dryland farming and pastoral areas of W.A. do not justify sustained use of amendments which would reduce soil exchangeable sodium contents. Efficient management of sodic soils in these areas must rely on the prevention of degradation and the use of biological and physical means to maintain adequate soil physical properties. Effective restoration of degraded sodic soils, however, often does require application of inorganic amendments in combination with tillage to initiate structural recovery. Sodicity is currently not considered to be a problem at any of the three main irrigation areas in W.A., but all have sodic soil within their potentially irrigable lands, which may limit their future expansion.
4
ANAND, R. R., i R. J. GILKES. "Iron oxides in lateritic soils from Western Australia". Journal of Soil Science 38, nr 4 (grudzień 1987): 607–22. http://dx.doi.org/10.1111/j.1365-2389.1987.tb02158.x.
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Riley, I. T., i S. J. Kelly. "Endoparasitic nematodes in cropping soils of Western Australia". Australian Journal of Experimental Agriculture 42, nr 1 (2002): 49. http://dx.doi.org/10.1071/ea01054.
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Soil samples were collected in Western Australia from cereal fields at about harvest time to determine levels of the endoparasitic nematodes, Pratylenchus and Heterodera. A systematic survey in 1997 and 1998 centred on the 40 shires with the highest proportion of cereal cropping. One hundred and eighty samples were collected in 1997 and 227 in 1998 at 10-km intervals along north–south transects 35 km apart. A targeted survey in 1997 included 98 soil samples from fields selected by growers as having poor productivity without an evident cause. No Heterodera cysts were found in any survey sample but these could be extracted from soils previously known to be infested. Pratylenchus neglectus was most commonly detected followed by P. thornei and P. zeae. Populations identified as P. brachyurus, P. penetrans, P. scribneri, and an undescribed species similar to P. thornei were also found. Overall Pratylenchus was extracted from 63% of samples (mean 1.1, median 0.3, max. 22.0/mL of soil). Maps of the data indicate that Pratylenchus populations were aggregated with some areas having relatively light infestations. There was a positive relationship with the intensity of cereal cropping and a negative relationship with pulse cropping. The findings indicate that potentially damaging Pratylenchus numbers occur in a significant proportion of fields and highlight the need to develop and implement strategies to lower population densities.
6
Chartres, CJ. "Sodic soils - an introduction to their formation and distribution in Australia". Soil Research 31, nr 6 (1993): 751. http://dx.doi.org/10.1071/sr9930751.
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This paper briefly summarizes existing Australian data about causes of sodicity and the distribution of sodic soils in Australia. Sources of salts and sodium include atmospheric accession, salts released by weathering processes and saline groundwaters. A traditional model of sodic soil pedogenesis is contrasted with more recent data demonstrating the role of several factors including mineralogy, EC/ESP relationships and exchangeable magnesium percentage on development and behaviour of sodic soils. Limited data about the national distribution of sodic soils are presented. There has been very little recent innovative research in Australia to increase understanding of soils affected by sodicity. A number of research needs are indicated.
7
Ward, P. R., i F. X. Dunin. "Growing season evapotranspiration from duplex soils in south-western Australia". Agricultural Water Management 50, nr 2 (wrzesień 2001): 141–59. http://dx.doi.org/10.1016/s0378-3774(01)00092-0.
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Gardner, WK, RG Fawcett, GR Steed, JE Pratley, DM Whitfield, Hvan Rees i Rees H. Van. "Crop production on duplex soils in south-eastern Australia". Australian Journal of Experimental Agriculture 32, nr 7 (1992): 915. http://dx.doi.org/10.1071/ea9920915.
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The environment, duplex soil types and trends in crop production in South Australia, southern New South Wales, north-eastern and north-central Victoria, the southern Wimmera and the Victorian Western District are reviewed. In the latter 2 regions, pastoral industries dominate and crop production is curtailed by regular and severe soil waterlogging, except for limited areas of lower rainfall. Subsurface drainage can eliminate waterlogging, but is feasible only for the Western District where subsoils are sufficiently stable. The other regions all have a long history of soil degradation due to cropping practices, but these effects can now be minimised with the use of direct drilling and stubble retention cropping methods. A vigorous pasture ley phase is still considered necessary to maintain nitrogen levels and to restore soil structure to adequate levels for sustainable farming. Future productivity improvements will require increased root growth in the subsoils. Deep ripping, 'slotting' of gypsum, and crop species capable of opening up subsoils are techniques which may hold promise in this regard. The inclusion of lucerne, a perennial species, in annual pastures and intercropping at intervals is a technique being pioneered in north-central and western Victoria and may provide the best opportunity to crop duplex soils successfully without associated land degradation.
9
Turner, NC. "Crop production on duplex soils: an introduction". Australian Journal of Experimental Agriculture 32, nr 7 (1992): 797. http://dx.doi.org/10.1071/ea9920797.
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Duplex or texture-contrast soils occur over about 60% of the agricultural areas of south-west Western Australia. Annual crops of wheat, barley, oats, and lupins predominate on these soils, grown in rotation with annual pastures. The climate is characterised by cool, wet winters and hot, dry summers. Crop production is restricted to the winter and spring and is limited by waterlogging in the wet winter months and by water shortage during grain filling in spring. Research on crop production on duplex soils has been undertaken for the past 8 years by a collaborative team from the CSIRO Dryland Crops andyoils Program and the Western Australian Department of Agriculture. This research has been focussed on 3 sites at which processes limiting crop production on duplex soils have been highlighted. This special issue was initiated to summarise that research and to put it in its regional and national perspective. Additionally, opportunity was taken to compare and contrast experiences both within Western Australia and throughout Australia, and to draw out management options for crop production on duplex soils.
10
Armour, JD, GSP Ritchie i AD Robson. "Extractable zinc in particle size fractions of soils from Western-Australia and Queensland". Soil Research 28, nr 3 (1990): 387. http://dx.doi.org/10.1071/sr9900387.
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The zinc (Zn) content of particle size fractions of 12 mainly Zn deficient soils was measured by extraction with three contrasting extractants. The soils, which ranged from sands to a black earth, were from Western Australia and Queensland and particle size fractions (clay, silt, fine sand, coarse sand) were obtained by sieving and sedimentation after ultrasonification of soil suspended in deionized water. The extractants were concentrated HNO3/H2SO4/HClO4 (acid extractable or AE-Zn), DTPA and 0.002 M CaCl2. For each extractant, Zn contents of the fractions and whole soils were correlated with organic carbon and ammonium oxalate extractable Fe and Al. The AE-Zn concentrations in whole soils were 0.6-132 mg kg-1 and high clay soils had higher concentrations (mean 54 mg kg-1) than low clay soils (mean 2 mg kg-1). After fractionation, lowest AE- and DTPA-Zn were found in coarse sand fractions and concentrations increased with decreasing particle size. Clay plus silt fractions contained 60-99% of the whole soil AE-Zn and 76-93% of the whole soil DTPA-Zn. The CaCl2-Zn concentrations were very low (<5.0 �g kg-1) for all soils. In whole soils, DTPA-Zn was only a small proportion, 3.2% and 1.8%, of the AE-Zn in the low clay and high clay soils, respectively. The CaCl2-Zn was generally less than 2% of the DTPA-Zn in whole soils. In whole soils, AE-Zn was correlated with oxalate extractable Fe and with oxalate A1 (r = 0.72 and 0.71, respectively; P <0.01), whereas DTPA-Zn was correlated with oxalate extractable Fe (r = 0.82; P < 0.01). The AE- and DTPA-Zn were correlated with organic carbon only in some fractions. The DTPA- and CaCl2-Zn were not correlated with AE-Zn content, nor was DPTA-Zn correlated with CaCl2-Zn in whole soils or fractions (P<0.05). Dispersion of the soils with ultrasonification in the absence of dispersing agents was not as effective as dispersion with conventional mechanical/chemical dispersion. The percentage of the soil recovered in the clay fraction after sonification was 23-78% of that recovered by the conventional method. Fine and coarse sand contents were similar for either method, indicating that incomplete dispersion of clay by ultrasonification resulted in higher silt contents.
11
Riley, MM, AD Robson, JW Gartrell i RC Jeffery. "The absence of leaching of molybdenum in acidic soils from Western Australia". Soil Research 25, nr 2 (1987): 179. http://dx.doi.org/10.1071/sr9870179.
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A glasshouse experiment was conducted to estimate the extent of leaching of molybdenum on acidic sandy soils from Western Australia. Sodium molybdate, at a rate equivalent to 40 g of molybdenum per hectare, was added to pots of soil either before or after leaching a column of the soil with the equivalent of 500 mm water. Molybdenum concentrations were determined in the leachate and in the wheat plants grown on the soils in pots after leaching. Approximately 10% of added molybdenum was removed with leaching from two grey sands, while negligible quantities were removed from three more acidic sandy soils. Leaching does not appear to be an important factor in the occurrence and recurrence of molybdenum deficiency on the yellow-brown acidic sandplain soils of the Western Australian wheatbelt.
12
Davidson, N. J., R. Galloway i G. Lazarescu. "Growth of Atriplex amnicola on Salt-Affected Soils in Western Australia". Journal of Applied Ecology 33, nr 6 (grudzień 1996): 1257. http://dx.doi.org/10.2307/2404768.
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Gregory, PJ, D. Tennant, AP Hamblin i J. Eastham. "Components of the water balance on duplex soils in Western Australia". Australian Journal of Experimental Agriculture 32, nr 7 (1992): 845. http://dx.doi.org/10.1071/ea9920845.
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The water balance of soils is of interest both in terms of crop productivity and of sustainability, because water that is not used by crops contributes not only to loss of yield but also to the processes of land degradation. Land clearance for agriculture in Western Australia has changed the hydrological balance resulting in greater drainage and increased secondary salinisation. The relative importance of components of the water balance changes with rainfall. In the drier, eastern wheatbelt, evapotranspiration dominates the balance and there is little drainage, except through narrow, preferred pathways. In contrast, in the wetter region of the Darling Peneplain up to 40% of rainfall may be lost by pathways other than evaporation. Movement of water at the interface of the sand and clay layers (throughflow) has been poorly quantified. The dominant direction of flow is vertical, but substantial lateral flow may occur during winter storms on sloping sites. For example, measurements at a site near Narrogin showed up to 15 mm of throughflow during the cropping season. Drainage using interceptor drains provides a practical means of removing the throughflow and reducing the incidence of waterlogging. Yields of wheat on duplex soils are poorly related to the amount of evapotranspiration. At low rainfall, the relationship is poor, because rainfall is rarely uniformly distributed throughout the season, and lack of water during grain-filling may depress yields. In high rainfall areas, there are few detailed studies of water use, but yields may be lower than anticipated because of waterlogging, low inputs of fertiliser, and disease.
14
Asumadu, K., R. J. Gilkes, H. M. Churchward i T. M. Armitage. "Detailed characterization of quartz grains in two sandy soils, Western Australia". Geoderma 41, nr 1-2 (grudzień 1987): 29–47. http://dx.doi.org/10.1016/0016-7061(87)90027-9.
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Jworchan, Indra, Tony O' Brien, Emged Rizkalla i Paul Gorman. "Engineering geology of Waterside Green, Sydney, Australia". Journal of Nepal Geological Society 34 (9.10.2006): 53–62. http://dx.doi.org/10.3126/jngs.v34i0.31879.
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Development of low-lying land affected by high water table in saline and sodic soils and local swampy areas remains a challenge for the local government, developers, and other regulators. The development control plan for a proposed residential or commercial subdivision in such a site in Penrith, Sydney, Australia, states that the drainage and stormwater management systems within and across the site should be improved and proposed buildings should be constructed on the ground higher than the 100-year flood level. This paper presents the results of engineering geological and geotechnical investigations for the proposed subdivision. The subsurface profile at the site comprises alluvial deposits underlain by residual soil, which in turn is underlain by shale and sandstone. In the eastern portion of the site, the alluvial deposits comprise a sequence of clay, sand and gravel, and in the western portion they contain a succession of clean sand and gravel. The alluvium in the eastern portion of the site is saline whereas it is generally non-saline in the western portion. All saline soils are sodic and most non saline ones are non-sodic. This paper discusses the suitability of on-site soils for use in a structural fill and impermeable clay liner as well as the management of saline and dispersive soils.
16
Naidu, R., RH Merry, GJ Churchman, MJ Wright, RS Murray, RW Fitzpatrick i BA Zarcinas. "Sodicity in South Australia - a review". Soil Research 31, nr 6 (1993): 911. http://dx.doi.org/10.1071/sr9930911.
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The current knowledge of the nature and distribution of sodic soils in South Australia is reviewed. The agriculturally developed area of South Australia lies south of latitude 32-degrees-S. and is mainly used for low intensity grazing and dry land cereal/sheep production. A high proportion of the State, including much of the high rainfall area, has soils which are sodic (>6% ESP) through a significant proportion of the profile but information on the precise nature of sodicity in these soils is limited. Where exchangeable cation data axe available, the analytical techniques used often did not precisely delineate between soluble salts in the soil and ions on exchange sites. Therefore, many of the datasets have major weaknesses and may be unreliable. Since many soils with ESP <6 also show dispersive characteristics typical of sodic soils, there is an urgent need for new sodicity studies relating to distribution and the criteria (ESP) used to identify dispersive soils. Information on the effect of sodicity on nutrient requirements of plants, especially the modern varieties, is scarce both locally and internationally, making development of management strategies for economically sustainable crop production difficult. Further, many different grades of gypsum are available in South Australia. Preliminary studies show the presence of impurities drastically influences gypsum dissolution characteristics. More effort is needed to assess the quality and reactivity of South Australian gypsum. Some effort has been directed by land managers towards reclamation and management of sodic soils by using both gypsum and lime either separately or as mixtures. However, there is neither a scientific basis for the application of gypsum-lime mixtures nor crop production data to support such management strategies.
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Dvurechenskaya, Elena B. "HALOGENESIS IN OLIGOTROPHIC SOILS OF THE MIDDLE TAIGA OF WESTERN SIBERIA". Географический вестник = Geographical bulletin, nr 3(54) (2020): 148–58. http://dx.doi.org/10.17072/2079-7877-2020-3-148-158.
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The paper provides analysis of salinization processes in the soils of middle taiga due to oil and petroleum products pollution of humid landscapes of Western Siberia. The specific features of man-made chloride-sodium halogenesis which develops in hydromorphic soils of Western Siberia have been investigated. The obtained materials have been initially processed: salt content, alkaline-acid characteristics, soil absorbent complex composition, and organic carbon content have been determined. There have been identified differences in lateral and radial migration of salts in peat bog soils of ryam and ridge-hollow bogs.
18
McFarlane, DJ, i JW Cox. "Management of excess water in duplex soils". Australian Journal of Experimental Agriculture 32, nr 7 (1992): 857. http://dx.doi.org/10.1071/ea9920857.
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Excess water in duplex soils can be removed by drains. In soils in which drainage is impractical, some success has been obtained by deep ripping and by gypsum amendment. These practices can increase profile storage or drainage. Interceptor drains are suitable for duplex soils with slopes of more than about 1.5%. On more gentle slopes, relief drains are used to remove excess water. Subsurface tube and mole drains have been used successfully to drain cereal crops in Victoria, but in Western Australia open drains are preferred because they can carry storm runoff as well as seepage waters. The greatest cost of open drains is the land removed from production. Over 35% of the rain falling during the growing season has been removed by drains in Victoria and Western Australia in wet years. Drainage was almost entirely downslope of monitored interceptor drains in Western Australia, which is not predicted from the theory. Simulation of water levels between drains and of drain flows using the DRAINMOD model indicated significant, preferred pathways for water flow to drains. The pathways explain the predominantly downslope effect of interceptor drains and the wide drain spacings which can be used. Deep ripping and the incorporation of gypsum can reduce waterlogging in some soils, but has had no effect in several others. The effect of deep ripping on recharge is unclear. Drains may decrease groundwater recharge, water and wind erosion, and soil structure decline. Their effect on phosphate export from catchments is unclear.
19
Mcfarlane, DJ, RJ Loughran i BL Campbell. "Soil erosion of agricultural land in Western Australia estimated by cesium-137". Soil Research 30, nr 4 (1992): 533. http://dx.doi.org/10.1071/sr9920533.
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The caesium-137 technique was used to estimate net soil loss from 10 hillslopes in the agricultural area of Western Australia. The gravel fraction of the soil was found to have approximately 56% of the total 137Cs activity found on the <2 mm fraction of the soil on three slopes where it was measured. In the lower rainfall zones, 137Cs appeared not to have uniformly labelled the soils in uncleared areas, possibly due to the redistribution of rainfall in the canopy and above the soil surface, and the water repellence of some soils. A previously established calibration curve was used to calculate net soil losses from the 10 hillslopes. Potato-growing land and slopes below rock outcrops in the Wheatbelt appear to have experienced the most severe erosion since the soils were first labelled with 137Cs in the mid 1950s (19-27 t ha-1 yr-1). Hillslopes below rock outcrops had appreciably less 137Cs than those below lateritic breakaways, indicating the presence of sheet erosion.
20
Bertrand, I., R. E. Holloway, R. D. Armstrong i M. J. McLaughlin. "Chemical characteristics of phosphorus in alkaline soils from southern Australia". Soil Research 41, nr 1 (2003): 61. http://dx.doi.org/10.1071/sr02021.
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This study was performed to better understand the chemical behaviour of P in a variety of alkaline soils from southern Australia. To do so, surface soil samples of 47 alkaline cropping soils from Upper Eyre Peninsula in South Australia and from western Victoria were collected. The 22 soils collected from Eyre Peninsula were Calcarosols, and those from western Victoria were Vertosols, Alkaline Duplex soils, Sodosols, and Red Brown Calcareous soils. Parameters included total and amorphous Al and Fe, organic C, organic P, CaCO3 content, P sorption characteristics, phosphorus buffer capacity, calcium lactate (Ca-Lac) extractable P, bicarbonate-extractable (Colwell) P, water-extractable P, anion exchange membrane extractable P (AEM-P), and isotopically exchangeable P (labile P). Concentrations of micronutrients in the Calcarosols were relatively low, considered to be a function of low clay contents. Given very low background Cd concentrations in the soils, it was estimated from Cd measurements that the majority of total P in the soils was derived from previous fertiliser applications. Phosphorus buffer capacities (PBCs) were relatively high in the Calcarosols and moderately high in the other alkaline soils. P sorption behaviour in the Calcarosols was a direct function of CaCO3 content, although in the other alkaline soils, amorphous Al and Fe oxides were the principal determinants of the P sorption behaviour. Both Colwell and Ca-Lac extractants dissolved non-labile P in the highly calcareous soils, whereas AEM appeared to only remove surface-adsorbed P. In addition, Colwell P values were positively related to PBC and to the slope term in the Freundlich model (Kf) when Kf > 10. It is suggested that AEM-P may be a better predictor of P availability in highly calcareous soils compared with the other extractants.
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Brennan, RF, i JF McGrath. "The vertical movement of zinc on sandy soils in southern Western Australia". Soil Research 26, nr 1 (1988): 211. http://dx.doi.org/10.1071/sr9880211.
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Fertilizer zinc applied to the surface of an acid sand of low cation exchange capacity remained close to the soil surface even after 1438 mm of rain. At levels of zinc typically used in agriculture and forestry (0.7 kg ha-1 Zn) there was no movement of zinc below 2.5 cm. Where zinc was applied at 22.5 kg ha-l, 95% of the applied zinc could be accounted for in the top 5 cm. At the higher rate of zinc application (68 kg ha-1 Zn), 37% of the applied zinc was recovered below 5 cm.
22
Samadi, Abbas, i R. J. Gilkes. "Forms of phosphorus in virgin and fertilised calcareous soils of Western Australia". Soil Research 36, nr 4 (1998): 585. http://dx.doi.org/10.1071/s97060.
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Total phosphorus (P), inorganic P (Pi), organic P, and several Pi fractions were determined for 8 fertilised calcareous soils under agriculture and their virgin analogues under natural bush to ascertain changes due to agricultural development. The relationships between soil properties and forms of P were also determined. In general, agricultural development of soils resulted in increases in total P (average 105% increase), Pi (154%), organic P (49%), Olsen P (200%), Colwell P (100%), and all Pi fractions compared with their virgin analogues. For the virgin soils, the abundance of the Pi fractions was in the order: Al-P>O-P (occluded P)>Fe-P>Ca10-P = Ca2-P>Ca8-P, which changed to Al-P>Ca8-P>Ca2-P>Ca10-P>Fe-P>O-P for fertilised soils. The average contribution of each fraction to the increase in total Pi was Al-P (29%), Ca8-P (26%), Ca2-P (18%), Fe-P (13%), Ca10-P (13%), and O-P (4%). The change in Ca8-P was closely correlated with the content of the active fraction of calcite in the soil (ACCE). The increase in Fe-P associated with agriculture was highly correlated with citrate-dithionite-bicarbonate (CDB) extractable Fe (Fed) and acid-ammonium oxalate extractable Fe (Feo). The increase in Al-P was correlated with the ratio of acid-ammonium oxalate extractable Al (Alo) to Feo. Both Olsen and Colwell NaHCO3-extractable P were highly correlated with Ca2-, Al-, Fe-, and Ca10-P, and total P values. Multiple regression analysis indicated that Ca2-P and Ca10-P were major contributors to available P as determined by the Olsen and Colwell soil tests.
23
Rovira, AD. "Dryland mediterranean farming systems in Australia". Australian Journal of Experimental Agriculture 32, nr 7 (1992): 801. http://dx.doi.org/10.1071/ea9920801.
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The mediterranean region of Australia extends from Geraldton in Western Australia across southern Australia into western and northern Victoria. This region experiences hot, dry summers and cool, wet winters, with 300-600 mm annual rainfall. In the dryland farming zone, the cereal-livestock farming system dominates and produces 30-35% of Australia's total agricultural production. The major soils in the region are deep, coarse-textured sands and sandy loams, duplex soils with coarse-textured sands over clay (generally low in nutrients and organic matter), and fine-textured red-brown earths of low hydraulic conductivity. Major soil problems in the region include sodicity, salinity, soil structural degradation, nutrient deficiencies, boron toxicity, acidity, waterlogging, inadequate nitrogen nutrition, water-repellence, and root diseases. These problems have been exacerbated by excessive clearing of trees, increased frequency of cropping, reduced area sown to pastures, declining pasture production, and a decline in nutrient levels. With improved soil management there is potential for increased productivity from dryland farming areas of the region and improved ecological sustainability.
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Tennant, David, David Tennant, David Hall i David Hall. "Improving water use of annual crops and pastures—limitations and opportunities in Western Australia". Australian Journal of Agricultural Research 52, nr 2 (2001): 171. http://dx.doi.org/10.1071/ar00005.
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As part of a wider analysis of the potential role for lucerne in farming systems being developed for containing the spread of salinisation, we have reviewed information generated in Western Australia on opportunities for improving the water use of annual crops and pastures. Substantial increases in water use have been shown to be possible in a number of situations and rainfall environments. Best gains, of the order of 40–70 mm, were reported on deep sand and loamy sand soil types. These were achieved from selection of deep-rooted and longer growing crop and pasture species, and from amelioration of widespread traffic pans and subsoil acidity, and/or selection of tolerant species. On more widespread gradational and duplex soils, soil physical and chemical properties that restrict water infiltration and/or root penetration to depth limit the potential to increase water use. Increases in production and water use are still possible, depending on the permeability of the lower horizons of these soils and on rainfall distribution. At best, recorded increases on these soils were of the order of 5–15 mm in short season, low rainfall environments, and around 40 mm in long season, high rainfall environments. These increases in water use were not invariable. Increases in water use were not noted in dry years on all soils and in all years on shallow duplex soils with impermeable B horizons. Seasonality impacts on all outcomes and is a key issue on all soils and in all rainfall environments.
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Pal, Y., R. J. Gilkes i M. T. F. Wong. "Mineral sources of potassium to plants for seven soils from south-western Australia". Soil Research 40, nr 8 (2002): 1357. http://dx.doi.org/10.1071/sr02014.
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This investigation was conducted with surface horizon samples from 7 south-western Australian soils and their 3 size fractions (sand, silt, and clay). The K release of these materials was measured for several extractants; the highest amounts of K were released from the clay (<2 μm) fraction. The presence of sand-size feldspars and incomplete removal of attached organic matter resulted in sand releasing significant amounts of K. The proportions of total K released in boiling 1 m HNO3 by the sand, silt, and clay fractions ranged from 0.4 to 3.4%, 2.6 to 36.3%, and 11.2 to 51.4%, respectively, and from 2.0% to 22.9% for the whole soils. Cumulative K uptake by 6 harvests of ryegrass over 260 days ranged from 0.26 to 1.23 cmol/kg soil.The clay fraction released higher proportions of total K to acid compared with the sand and silt size fractions because of the high specific surface area of the clay and because it contained proportionately higher amounts of illite, which releases K by both ion exchange and dissolution, whereas K release from feldspars requires congruent dissolution of the silicate structure. The differences in contents of StepK (relatively available fraction of the non-exchangeable K) and CRK (constant rate K) for 1 m HNO3 dissolution of these soils and size fractions reflect differences in mineralogical composition between the soils and size fractions. The low contents of StepK for the sand fraction indicated that K was strongly retained by feldspars. The soils with high CRK values had significant amounts of illite in the clay fraction. Values of CRK were positively related to cumulative K uptake and cumulative dry matter yield of ryegrass.
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Gerritse, RG, J. Beltran i F. Hernandez. "Adsorption of atrazine, simazine, and glyphosate in soils of the Gnangara Mound, Western Australia". Soil Research 34, nr 4 (1996): 599. http://dx.doi.org/10.1071/sr9960599.
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Sandy soils were sampled from second rotation sites of Pinus pinaster Ait. on the Gnangara Mound in Western Australia. Adsorption isotherms were measured for atrazine [6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine], simazine [6-chloro-N,N'-diethyl-1,3,5-triazine-2,4-diamine], and glyphosate [N-phosphonomethyl-aminoaceticacid]. Adsorption isotherms were also measured for degradation products of atrazine: hydroxyatrazine [6-hydroxy-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine] (HA), desethylatrazine [6-chloro-N-isopropyl-1,3,5-triazine-2,4-diamine] (DEA); and of glyphosate: aminomethylphosphonic acid (AMPA). The adsorption of the 2 triazines was proportional to soil organic carbon content and was not affected significantly by other soil parameters. The affinity for soil organic carbon was in the order atrazine = simazine = DEA > HA. Affinity of atrazine for the type of organic matter in the Gnangara Mound soils (expressed as Koc) was significantly greater than is commonly reported for other soils. The adsorption of glyphosate and AMPA increased strongly with iron and aluminium content of soils and decreased with increasing soil organic carbon content. This would indicate that glyphosate and AMPA are mainly adsorbed by clay minerals, while soil organic matter competes for adsorption sites and inhibits adsorption. Contrary to what is usually reported for batch adsorption of pesticides in soils, significant increases in adsorption of the triazines and glyphosate were measured after 1 day of equilibration.
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Hughes, JC, i RJ Gilkes. "Rock phosphate dissolution and bicarbonate-soluble-P in some soils from South-Western Australia". Soil Research 32, nr 4 (1994): 767. http://dx.doi.org/10.1071/sr9940767.
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Samples were collected from 228 soils from the main agricultural areas of Western Australia (W.A.) and their chemical and textural properties analysed. Soils were incubated for 7 days with North Carolina rock phosphate at a rate equivalent to 1022 �g Ca g(-1) and 383 �g P g(-1) soil. Subsequently, the amount of rock phosphate (RP) that had dissolved was determined by measuring the increase in extractable calcium (�Ca) and changes in plant-available P were estimated by a sodium bicarbonate extraction (�Bic-P). Only 29 soils dissolved more than 40% of the added RP and these occur in the wettest area of W.A., to the west of the 800 mm rainfall isohyet. They represent a variety of soil types including Vertisols, Spodosols, Alfisols and Ultisols. Simple and multiple regressions were carried out to investigate the soil properties responsible for RP dissolution and associated P availability. No single soil property adequately predicted RP dissolution or concomitant changes in bicarbonate-P. Titratable acidity and sand content together explained 61% of the variance in RP dissolution; titratable acidity was the most predictive single variable for bicarbonate-P but only explained 56% of the variance. Stepwise regression showed that titratable acidity and pH(CaCl2) together explained 79% of the variance in bicarbonate-P. The most suitable soils for RP application are sandy, humic or peaty podzols where much of the dissolved P remains available to plants. The other soils (mainly red and yellow earths and Vertisols) which dissolved much RP contain larger amounts of extractable aluminium (by dithionite or oxalate) which is the soil component largely responsible for P-sorption in these W.A. soils. These results indicate that RP fertilizers will be most effective on the humic, sandy podzols of the western and southern coastal plains of WA.
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Ruprecht, JK, i NJ Schofield. "In situ neutron moisture meter calibration in lateritic soils". Soil Research 28, nr 2 (1990): 153. http://dx.doi.org/10.1071/sr9900153.
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An in situ calibration procedure for complex lateritic soils of the jarrah forest of Western Australia is described. The calibration is based on non-destructive sampling of each access tube and on a regression of change in water content on change in neutron count ratio at 'wet' and 'dry' times of the year. Calibration equations with adequate precision were produced. ever, there were high residual errors in the calibration equations which were due to a number of factors including soil water variability, the presence of a duricrust layer, soil sampling of gravelly soils and the variability of the cement slurry annulus surrounding each access tube. The calibration equations derived did not compare well with those from other studies in south-west Western Australia, but there was reasonable agreement with the general equations obtained by the Institute of Hydrology, U.K.
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Biggs, A. J. W., K. Bryant i K. M. Watling. "Soil chemistry and morphology transects to assist wetland delineation in four semi-arid saline lakes, south-western Queensland". Soil Research 48, nr 3 (2010): 208. http://dx.doi.org/10.1071/sr09127.
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Soils at 4 saline lakes (Wyara, Numalla, Wombah and Bindegolly) in semi-arid south-western Queensland were described and sampled to determine soil attributes that assist in the delineation of wetlands. Up to 4 sites were described in transects perpendicular to the lake edge. Samples from fixed depths were analysed for limited ionic chemistry and, in some cases, selected acid sulfate soil parameters. Lakebed soils were alkaline Hypersalic Hydrosols, changing to a variety of soils, including alkaline Rudosols and Podosols on adjacent lunettes and beach ridges. Gley colours and mottling were indicative of lakebed soils, while redder colours and stratification were common in soils outside the wetland. Evaporative concentration of salts at the soil surface was common in lakebed and transition zone soils, whereas leaching of salts was common in sandier soils outside the wetlands. Analysis of acid sulfate soil parameters and field evidence in the beds of Lakes Wyara and Wombah confirmed the presence of unoxidised sulfidic sediments and extensive neutralising capacity. Wave action formation of beach ridges appeared to be the most prevalent land-forming process at 3 lakes, but wind-driven deflation with associated lunette-building was evident at Lake Bindegolly. The data confirmed the value of pedological features such as texture, colour, and salinity trends in determining the boundaries of these wetlands, but also highlighted the transient nature of these features.
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Anderson, WK, RJ French i M. Seymour. "Yield responses of wheat and other crops to agronomic practices on duplex soils compared with other soils in Western Australia". Australian Journal of Experimental Agriculture 32, nr 7 (1992): 963. http://dx.doi.org/10.1071/ea9920963.
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A survey of experimental results relating crop management to grain yield was conducted for wheat and other crops on duplex and non-duplex soils in the wheatbelt of Western Australia. Increases in grain yield of wheat due to improved agronomic practices on duplex soils were almost as great as on other soils. Early sowing improved yield more on duplex soils than on other soils, but the response to applied nitrogen was more variable, possibly related to the reduced efficiency of uptake of applied nitrogen. The yield advantage for a semi-dwarf cultivar (Aroona) over a tall cultivar (Garnenya) was less (6%) on duplex soils than on other soils (29%). The optimum seed rate was 27% greater on duplex than on other soils. Increases in both grain yield and grain quality due to the application of potassium were large on 1 duplex soil. Water use efficiency in grain production was similar on duplex and other soils where seasonal water use did not exceed about 350 mm. At 1 location in the eastern wheatbelt, yields of wheat, barley, lupins and peas grown on a duplex soil were compared with yields on 2 other soils. Wheat was the most productive crop on the duplex soil, while barley yielded most on the other soils. All crops, except lupins, yielded less on the duplex soil. Experiments with 2 lupin cultivars grown on duplex and other soils on the south coast of Western Australia (average growing season rainfall >300 mm) showed that both cultivars yielded less on duplex soils, but 1 cultivar required slightly fewer plants to achieve its maximum yield on the duplex soils. This survey of experimental results in Western Australia shows that duplex soils are no less productive than other soils when results are averaged over all crops and locations. We conclude, however, that different management practices may be required to improve yields on duplex compared with other soils.
31
Gill, GS, ML Poole i JE Holmes. "Competition between wheat and brome grass in Western Australia". Australian Journal of Experimental Agriculture 27, nr 2 (1987): 291. http://dx.doi.org/10.1071/ea9870291.
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Brome grass (Bromus diandrus Roth) has become a serious weed of wheat in Western Australia, particularly on light textured soils. Six field experiments were carried out to investigate competition between brome grass and wheat. Results showed that brome grass is an extremely aggressive weed in wheat. Although the experimental sites varied considerably in soil type, rainfall and other growing conditions the relationship between brome grass and reduction in wheat yield was remarkably consistent across the sites. An exponential model was found to adequately describe yield loss due to competition with brome grass and will be used for extension purposes in Western Australia. An examination of yield contributing characters of wheat suggested that yield loss due to brome grass had been determined before the crop reached the grainfilling stage and such a result diminishes the importance of competition for water in wheat-brome grass mixtures.
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Summers, RN, NR Guise, DD Smirk i KJ Summers. "Bauxite residue (red mud) improves pasture growth on sandy soils in Western Australia". Soil Research 34, nr 4 (1996): 569. http://dx.doi.org/10.1071/sr9960569.
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Red mud is a finely crushed, iron-rich, alkaline residue, obtained by digesting bauxite with caustic soda to remove the alumina. The remnant alkalinity of red mud is equivalent to 11% pure calcium carbonate. Phosphorus leaching from infertile sandy soils has resulted in eutrophication of estuaries and has caused algal blooms. Red mud has been shown to reduce leaching of phosphorus from sandy soil. This research was undertaken to determine the effect of red mud on pasture growth and uptake of heavy metals. Red mud, either untreated or treated with gypsum, was applied at rates of 0, 10, 20, 40, and 80 t/ha to a subterranean clover and ryegrass hay paddock. There were 3 replicates of each treatment and a completely randomised design was used. The experimental design was 5 rates of red mud x 2 untreated and treated with gypsum x 3 replicates, resulting in 30 plots. Plant growth, and nutrient and heavy metal composition of the plant tops, were measured. An application of 40 t/ha of red mud increased hay (mainly subterranean clover and ryegrass) production by 24% and increased soil pH in the top 10 cm by 1.0 unit from 3.5 (1 : 5 soil : 0.1 M CaCl2). The increase in production was probably because of the liming effect of the remnant alkali in the red mud, which may have potential as a replacement for crushed limestone. Sodium carbonate, the predominant alkali in red mud, is more soluble than calcium carbonate from crushed limestone and has the potential to change the pH of the soil more rapidly. The soil was top-dressed with red mud, without disturbing the existing pasture, resulting in changes to the pasture production and nutrient composition consistent with a change in soil pH throughout the rooting depth. If crushed limestone is not mixed into the soil it may take many years to increase the pH of the soil; however, this mixing results in extra cost from re-seeding and an initial depression in yield. Although much more red mud is needed than lime, the cost is comparable when the haulage distance is less than about 30 km. In previous trials, at red mud application rates > 500 t/ha, gypsum was mixed into the red mud to reduce salinity and pH. At these rates, the red mud had overwhelmed the buffering capacity of the soil. The gypsum reduced the pH by changing the sodium carbonate in the red mud to calcium carbonate, thus changing the pH from > 10 to about 8.5. However, amendment of the red mud with gypsum when applied at rates < 80 t/ha proved unnecessary in this experiment, probably because the proportion of soil was sufficient to alter the pH of the red mud. When red mud is applied to acidic infertile sands, manganese application as manganese sulfate may be necessary, because the rise in pH may rapidly induce manganese deficiency in plants. Care should be taken to monitor other nutrients which have their availability for plants affected by pH (e.g. copper, zinc, and molybdenum). Red mud did not elevate the concentrations of heavy metals in the soil, hay, or fresh plant tissue.
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Bennet-Chambers, M., P. Davies i B. Knott. "Cadmium in aquatic ecosystems in Western Australia: A legacy of nutrient-deficient soils". Journal of Environmental Management 57, nr 4 (grudzień 1999): 283–95. http://dx.doi.org/10.1006/jema.1999.0304.
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Prior, Lynda D., Ben J. French, Kathryn Storey, Grant J. Williamson i David M. J. S. Bowman. "Soil moisture thresholds for combustion of organic soils in western Tasmania". International Journal of Wildland Fire 29, nr 7 (2020): 637. http://dx.doi.org/10.1071/wf19196.
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The present study aimed to determine moisture thresholds for combustion of organic soils sampled from various vegetation types at 63 locations in Tasmania, Australia. To observe whether the soil sample sustained smouldering combustion, moisture content was experimentally manipulated and heat was applied. Combustion was primarily determined by moisture content, but was also influenced by soil bulk density and organic content: the gravimetric moisture content corresponding to a 50% probability of burning ranged from 25 to 94% as organic content varied from 34 to 96%. There was no evidence of differences among vegetation types in the relationship between soil combustibility and organic content. Combustion in Tasmanian organic soils occurred with moisture levels similar to those reported elsewhere, despite differences in vegetation and environment. It was also found that a hand-held meter that measured volumetric moisture content using time domain reflectometry could be used to satisfactorily predict organic soil combustion. Finally, combining the data with estimates of volumetric soil moisture based on high-resolution gridded weather data (Bureau of Meteorology Atmospheric high-resolution Regional Reanalysis for Australia, or BARRA), it was demonstrated that most Tasmanian organic soils are likely to be combustible at some time almost every summer (December to February).
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Bowman, DMJS. "Monsoon Forests in North-Western Australia. II. Forest-Savanna Transitions". Australian Journal of Botany 40, nr 1 (1992): 89. http://dx.doi.org/10.1071/bt9920089.
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Presence-absence data for tree species in over 1000 quadrats, 10 ° 20m, on 144 transects were analysed by the divisive classificatory program TWINSPAN in order to define wet or dry monsoon forest, ecotone and savanna assemblages. A sorted table revealed that there was continuous floristic variation among these six vegetation types, although the abundance of tree species varied highly significantly between assemblages. Both wet and dry monsoon forests have higher stem densities, greater basal area, more tree species, higher litter cover and lower grass cover than surrounding savannas. Wet monsoon forest soils have significantly more moisture than surrounding savanna, but on the dry monsoon forest-savanna boundary there is no significant difference in soil moisture. Both wet and dry monsoon forest soils are more fertile than those in surrounding savannas, although there is considerable variation in the concentration of nutrients within and between the two forest formations. The greater fertility of the forest probably reflects superior nutrient accretion compared with the savanna, rather than indicating that monsoon forests are restricted to inherently fertile sites. Half the wet monsoon forest boundaries sampled had ecotonal quadrats separating forest from savanna, while only 18% of the dry monsoon forest boundaries had such structurally and floristically intermediate quadrats. A limited number of tree species was found to dominate both wet and dry forest ecotones. Wet forest ecotones are overall environmentally more similar to the surrounding savanna than the adjoining forests. Dry forest ecotones are environmentally intermediate between the dry forest and savanna. Both wet and dry forests have less fire damage than surrounding savannas. In contrast to the edaphic control of most wet monsoon forests, dry forests are typically restricted to fire protected niches. The distribution of both wet and dry forest, ecotone and savanna on boundaries with no edaphic or topographic discontinuities is thought to reflect a dynamic relationship between these assemblages.
36
ROBINSON, ALASTAIR S., ADAM T. CROSS, MANFRED E. MEISTERL i ANDREAS FLEISCHMANN. "A new pygmy sundew, Drosera albonotata (Droseraceae), from the western Wheatbelt and an updated diagnostic key to the orange-flowered pygmy Drosera of Western Australia". Phytotaxa 346, nr 3 (6.04.2018): 221. http://dx.doi.org/10.11646/phytotaxa.346.3.2.
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A new species of Drosera—Drosera albonotata—from the western Wheatbelt (Western Australia) is described and illustrated. The taxon, which is largely restricted to sandy clay loam soils in Wandoo woodland and shrubland, is morphologically similar to D. miniata and D. coomallo but can be distinguished by its distinct floral features and ecology. A distribution map of the new species and its allies and a revised and updated diagnostic key to the twelve recognised orange-flowered pygmy Drosera in Western Australia are provided.
37
Pal, Y., R. J. Gilkes i M. T. F. Wong. "The forms of potassium and potassium adsorption in some virgin soils from south-western Australia". Soil Research 37, nr 4 (1999): 695. http://dx.doi.org/10.1071/sr98083.
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This investigation was undertaken to determine the potassium (K) status and adsorption behaviour of 227 samples from horizons of 41 representative virgin soil profiles, extending from Geraldton in the north to the Great Southern district of Western Australia. X-ray diffraction analysis of random powder of whole soil indicated that quartz is the dominant mineral and some soils contain significant amounts of feldspars. Clay mineralogy is dominated by kaolinite but minor quantities of illite are present in some soils. Most south-west Australian agricultural soils contain little available K: NaHCO3-extractable K (NaHCO3-K, median value 0·09 cmol K/kg, equivalent to 35 mg K/kg soil), HNO3-extractable K (HNO3-K, median value 0·30 cmol K/kg, equivalent to 117 mg K/kg soil), and total K (XRF determined K, median value, 17 cmol K/kg, equivalent to 6630 mg K/kg soil). The proportion of water-soluble K (H2O-K) ranges from 0 to 3·5% of total K, 0 to 76% of HNO3-K, and 0 to nearly 100% of exchangeable K. Exchangeable K ranges from 0 to 100% (median value 37%) of HNO3-K. These are relatively high proportions of H2O-K and exchangeable K compared with soils from many other parts of the world. The amounts of all forms of K variously increase or decrease downwards in the soil profile depending on both clay content and mineralogy. The commonly assumed increase in K with clay content alone is invalid. The soils mostly have low-to-moderate values of K sorption capacity, ranging from 5% to 67% (median value 14%) of added K (initially 4·1 mM K/L, equivalent to 4·1 cmol K/kg). otassium sorption isotherms conform well to the Freundlich equation. The inability of the Langmuir equation to describe the data may indicate that there are several types of K sorption sites in these soils. The Gapon coefficient KG varied widely from 0·04 to 29·8 (L/mol) ½ [median value 5·4 (L/mol) ½ ].
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Brennan, R. F. "Residual value of molybdenum for wheat production on naturally acidic soils of Western Australia". Australian Journal of Experimental Agriculture 46, nr 10 (2006): 1333. http://dx.doi.org/10.1071/ea05101.
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Naturally acidic sandplain soils in the lower rainfall (<350 mm annual average) eastern region of the agricultural areas of south-western Australia are deficient in molybdenum (Mo) for grain production of wheat. Liming soils ameliorates Mo deficiency, but it is not an economic option for these soils because they are naturally acidic at soil depths commonly explored by wheat roots. Consequently, Mo fertiliser, usually as Mo trioxide, needs to be applied to wheat on these soils. The residual value of the Mo fertiliser for these soils was not known, so was measured using grain yield of wheat in 2 long-term field experiments. The Mo fertiliser treatments were applied once only in different years to plots not treated with Mo in a previous year. In both experiments, the residual value of the fertiliser was measured in 1993. Thus, it was possible to determine the effectiveness of the fertiliser applied once only 1–11 years previously (previous Mo) relative to freshly applied (current) Mo applied in 1993. At both sites, a continuous decline in the effectiveness of previous Mo relative to current Mo was related to time of Mo–soil contact. In experiment 1, the effectiveness of previous Mo relative to current Mo decreased by about 40, 50, 60 and 70% when applied 2, 5, 7 and 11 years previously. In experiment 2, on a more acidic soil with a larger capacity to sorb Mo, the relative effectiveness of previous Mo decreased by about 60 and 80% for Mo applied 2 and 6 years previously. The concentration of Mo measured in youngest emerged leaf blades was related to 90% of the maximum shoot yield at the time of sampling (diagnostic critical tissue test value) and to 90% of the maximum grain yield (prognostic critical tissue test value). Irrespective of the growth stage of wheat, both critical diagnostic and prognostic values were about 0.07 mg Mo/kg. The concentration of Mo in grain that was related to 90% of the maximum grain yield was 0.02 mg/kg. The reapplication of Mo fertiliser to naturally acidic sands can be made with knowledge of the residual value and use of tissue testing for Mo, particularly when sampled at early growth stages of wheat.
39
Walker, SR, i WM Blacklow. "Correction". Soil Research 33, nr 4 (1995): 733. http://dx.doi.org/10.1071/sr9950733.
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Cox, JW, DJ Mcfarlane i RW Skaggs. "Field-evaluation of DRAINMOD for predicting waterlogging intensity and drain performance in South-Western Australia". Soil Research 32, nr 4 (1994): 653. http://dx.doi.org/10.1071/sr9940653.
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Waterlogging is common on sloping duplex soils in south-western Australia and causes damage to non-irrigated cereal crops and pastures. The factors which affect the performance of surface seepage interceptor drains installed to reduce this waterlogging are complex because the soils are very variable and have preferred pathways for groundwater flow. We compared DRAINMOD's predictions with field measured waterlogging intensity and drain flow over 3 years near Mt Barker and Narrogin in Western Australia. DRAINMOD failed to accurately predict waterlogging intensities and drain flows because water can move through macropores which bypass the soil matrix. At Mt Barker, DRAINMOD overpredicted waterlogging intensity by between 120% in a wet year and 650% in a very dry year. Drain flows were underpredicted by 148% in the driest year. At Narrogin, DRAINMOD underpredicted waterlogging intensity each year (rainfall was below average each year) and drain flow in the driest two years. However, by increasing Ks of the topsoil and adjusting Ks of the subsoil clay, DRAINMOD predictions agreed with measured responses. DRAINMOD can be used to predict waterlogging intensities and drain flows in duplex soils in the >450 mm annual rainfall areas of south-western Australia provided adjustments are made to the field point-measured Ks. Reliability increases with increasing rainfall during the growing season.
41
French, R. J., R. J. French, M. W. Sweetingham, M. W. Sweetingham, G. G. Shea i G. G. Shea. "A comparison of the adaptation of yellow lupin (Lupinus luteus L.) and narrow-leafed lupin (L. angustifolius L.) to acid sandplain soils in low rainfall agricultural areas of Western Australia". Australian Journal of Agricultural Research 52, nr 10 (2001): 945. http://dx.doi.org/10.1071/ar00084.
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Almost the entire lupin industry of Western Australia is based on the single species Lupinus angustifolius L. (narrow-leafed lupin), which is very well adapted to coarse-textured, mildly acid soils. However, L. angustifolius is not well suited to the strongly acid sand plain soils along the low rainfall fringe of Western Australia’s agricultural areas, and alternative grain legume species may be preferable. These soils, known locally as wodjil soils, have very low nutrient contents, often high levels of extractable Al in the subsoil, and are common in areas where severe brown spot and root rot disease is caused byPleiochaeta setosa. Yellow lupin, Lupinus luteus L., may be a better species on these soils. This paper describes a series of trials comparing the grain yields of narrow-leafed lupin and yellow lupin on a range of soils in the agricultural areas of Western Australia. These trials were sown on a range of dates and in a range of rotational backgrounds between 1995 and 1998. With current cultivars, narrow-leafed lupin clearly has higher yield potential than yellow lupin when soil-extractable [Al] at a depth of 15–25 cm (measured in a 1 :5 extract of soil in 0.01 M CaCl2) is <10 mg/kg. When extractable [Al] at this depth is greater, yellow lupin can produce greater yields than narrow-leafed lupin, depending on other environmental characteristics, especially when extractable [Al] exceeds 28 mg/kg, but its yield advantage is often small. Yellow lupin is less sensitive to delayed sowing than narrow-leafed lupin, and more tolerant of brown spot, but narrow-leafed lupin is more responsive to good seasonal conditions and less sensitive to frost. We conclude that yellow lupin has a place in Western Australian farming systems on soils with >10 mg/kg extractable [Al] where these soils are in close lupin rotations, in areas where brown spot is severe, or in low rainfall areas where narrow-leafed lupin yield potential does not often exceed 1 t/ha on these soils. However, yellow lupin has had relatively little breeding effort in Australia and its place will remain precarious until better adapted, higher yielding cultivars become available.
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Dolling, P. J., R. A. Latta, P. R. Ward, M. J. Robertson i S. Asseng. "Soil water extraction and biomass production by lucerne in the south of Western Australia". Australian Journal of Agricultural Research 56, nr 4 (2005): 389. http://dx.doi.org/10.1071/ar04158.
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To understand the factors involved in lucerne reducing drainage below the root-zone and influencing lucerne biomass production and water extraction were analysed in the south of Western Australia. The lucerne was grown for 3 years before removal. The factors investigated as part of the water extraction analysis included the rate of advance of the extraction front or extraction front velocity (EFV, mm/day), the soil plant-available water-holding capacity (PAWC, mm/m soil), and the temporal change in soil water deficit (drainage buffer, mm). The drainage buffer is related to the EFV and PAWC. A site with deep sand had the highest EFV (mean of 9.2 mm/day) but the lowest PAWC (mean of 32 mm/m soil) to a depth of 4 m. In the duplex soils the EFV was 18–34% of the deep sand EFV and the PAWC was 60–222% higher than the deep sand PAWC to a depth of 1.6–2.1 m. The EFV was reduced by the higher clay content and sodicity in the B horizon of the duplex soils. The highest drainage buffer measurements occurred in the deep sand site and the better structured duplex soils and therefore these soils will have the greater effect on reducing drainage below the root-zone. However, lucerne was able to create a drainage buffer to at least a depth of 1.5 m over 3 years and therefore contribute to a reduced drainage even on the most sodic and saline sites. Low soil pH did not affect the drainage buffer as much as soil texture and structure. Variation in biomass production of lucerne-based pastures was positively related to rainfall and water use (taking into account soil water storage and drainage losses) across sites, explaining approximately 50% of the biomass variation. Rainfall and water use could therefore be used for predicting lucerne biomass production in Western Australia. Biomass water use efficiency was highest in spring (15 kg/ha.mm) and least during autumn (4.5 kg/ha.mm).
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Tennant, D., G. Scholz, J. Dixon i B. Purdie. "Physical and chemical characteristics of duplex soils and their distribution in the south-west of Western Australia". Australian Journal of Experimental Agriculture 32, nr 7 (1992): 827. http://dx.doi.org/10.1071/ea9920827.
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Duplex soils are widespread in Western Australia and occupy about 60% of the south-west agricultural area. The physical and chemical properties of these soils reflect their origin as erosional surfaces of old laterite profiles and the predominance of underlying, quartz-rich, granitic materials. The resulting combination of high contents of quartz sand, kaolin clay, and iron and aluminium oxides has important consequences on water-holding capacity, fertility, nutrient leaching, phosphate fixation, anion and cation exchange capacity, and buffering capacity. These soils are generally held to have a number of physical and chemical problems. Among these, low fertility and low permeability of the clay B horizon have greatest effect. While data on the chemical properties of these soils are limited, significant data sets on the physical properties of duplex soils are available from several studies of catchment hydrology. These studies reflect concern with runoff, waterlogging, and the development of secondary salinisation. Depth to clay varies from 5 to >100 cm. The shallower depths (10-40 cm) predominate and, in medium and high rainfall areas, combine with low permeability in the clay to result in widespread waterlogging. Commonly, the sand surface can be hardsetting and can have high strength from structural decline, from the presence of cementing agents, and from traffic effects. Sodicity is widespread and has effects on hardsetting in the A horizon and on permeability of the B horizon. Management strategies are available to treat some of these problems, but generally, much has yet to be done to develop sustainable agricultural systems on these soils.
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Gerritse, RG. "Effect of reaction-rate on leaching of phosphate through sandy soils of Western-Australia". Soil Research 33, nr 1 (1995): 211. http://dx.doi.org/10.1071/sr9950211.
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The effect of reaction rate on the mobility of phosphate in soils was measured from breakthrough curves in the leachate from small columns of soil, following step increases in the input concentration of phosphate. Average mobilities of phosphate in columns of soil, following a step increase in the input concentration, decrease with decreasing rate of flow and with increasing distance travelled and appear to be linearly correlated on a log-log scale with both flow rate and distance travelled. An empirical equation, describing these relationships, fits data from leaching experiments at flow rates between 30 and 600 cm/day in columns of soil ~10-30 cm in length. Two coefficients are required and are obtained by curve fitting breakthrough curves, calculated with a numerical computer simulation model, to experimental breakthrough curves. The fitted equation enables extrapolation to flow rates and distances travelled that are more relevant to a field situation.
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Loughman, RJ, DJ Mcfarlane, BL Campbell i R. Shepherd. "The Distribution of Caesium-137 in Rangeland Soils at Three Sites in Western Australia." Rangeland Journal 15, nr 1 (1993): 24. http://dx.doi.org/10.1071/rj9930024.
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Soil sampling for the fallout isotope caesium-137 (137Cs) was canied out on three pastoral properties in Western Australia to assess its suitability for estimating soil erosion status. The sites were situated east and north-east of Geraldton in a region receiving an annual rainfall of approximately 200 rnm. It was hypothesised that 137Cs levels would be lower outside Department of Agriculture exclosures, established in the early 1950s, because of higher rates of soil erosion due to pastoral activities. The exclosures are areas of fenced-off rangeland which have the purpose of excludin'g in11 herbivores. It was further hypothesised that 137Cs levels would be related to microtopography in this rangeland-plains landscape. Soil erosion and deposition have given rise to scalds and soil mounds under shrubs, respectively, and amounts of 137Cs at these sites could reflect these processes. The Mann-Whitney U test showed that there were no significant differences in 137Cs levels between samples collected inside and outside the exclosures. At one property there was a significant relationship between 137Cs and microtopography (U test: sig. 0.025 level), suggesting that soil erosion was more severe on open and scald sites than under shrubs. No detectable 137Cs was found at 23% of all sites, but there was evidence that localized deposition of sediments had occurred. Because the total number of samples used in this survey was small, further work will be required to confirm the utility of the 13'Cs technique for measuring erosion status in arid Australia.
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Hayes, Patrick E., Peta L. Clode, Caio Guilherme Pereira i Hans Lambers. "Calcium modulates leaf cell-specific phosphorus allocation in Proteaceae from south-western Australia". Journal of Experimental Botany 70, nr 15 (9.04.2019): 3995–4009. http://dx.doi.org/10.1093/jxb/erz156.
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Abstract Over 650 Proteaceae occur in south-western Australia, contributing to the region’s exceptionally high biodiversity. Most Proteaceae occur exclusively on severely nutrient-impoverished, acidic soils (calcifuge), whilst only few also occur on young, calcareous soils (soil-indifferent), higher in calcium (Ca) and phosphorus (P). The calcifuge habit of Proteaceae is explained by Ca-enhanced P toxicity, putatively linked to the leaf cell-specific allocation of Ca and P. Separation of these elements is essential to avoid the deleterious precipitation of Ca-phosphate. We used quantitative X-ray microanalysis to determine leaf cell-specific nutrient concentrations of two calcifuge and two soil-indifferent Proteaceae grown in hydroponics at a range of Ca and P concentrations. Calcium enhanced the preferential allocation of P to palisade mesophyll (PM) cells under high P conditions, without a significant change in whole leaf [P]. Calcifuges showed a greater PM [P] compared with soil-indifferent species, corresponding to their greater sensitivity. This study advances our mechanistic understanding of Ca-enhanced P toxicity, supporting the proposed model, and demonstrating its role in the calcifuge distribution of Proteaceae. This furthers our understanding of nutrient interactions at the cellular level and highlights its importance to plant functioning.
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Humphries, A. W., X. G. Zhang, K. S. McDonald, R. A. Latta i G. C. Auricht. "Persistence of diverse lucerne (Medicago sativa sspp.) germplasm under farmer management across a range of soil types in southern Australia". Australian Journal of Agricultural Research 59, nr 2 (2008): 139. http://dx.doi.org/10.1071/ar07037.
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The persistence of a diverse group of lucerne (Medicago sativa sspp.) germplasm was evaluated under farmer management across a range of acidic and neutral-alkaline soils at 8 sites in South and Western Australia. Dryland field trials were sown in parallel with commercial lucerne paddocks being grown in rotation with cereal crops, remaining unfenced and under management by the farmer for the life of the stand. The combined differences in soil type, grazing management, and low rainfall contributed to large differences in average lucerne persistence between sites in South Australia and Western Australia. After 3 years, plant frequency (a measure of plant density used to monitor persistence) averaged 17% (at least 17 plants/m2) on the strongly acidic soils in Western Australia and 30% on the neutral-alkaline soils in South Australia (at least 30 plants/m2). Differences in persistence were attributed to the combined stresses of soil pH, drought conditions, and grazing management. Genetic correlation analyses between sites failed to show any clear patterns in the performance of entries at each site, except for a high correlation between 2 South Australian sites in close proximity. Highly winter-active germplasm was less persistent than other winter activity groups, but was higher yielding when assessed in an additional trial at Katanning, WA. Highly winter-active lucerne (class 9–10) should continue to be recommended for short (2–4 year) phases in rotation with cereals, and winter-active groups (6–8) should be recommend for longer (4–7 year) phases in rotations. The results of this evaluation are also being used to identify broadly adapted, elite genotypes in the breeding of new lucerne cultivars for the southern Australian cropping districts.
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Singh, B., i RJ Gilkes. "Phosphorus sorption in relation to soil properties for the major soil types of South-Western Australia". Soil Research 29, nr 5 (1991): 603. http://dx.doi.org/10.1071/sr9910603.
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The P sorption characteristics of 97 soils that are representative of the agricultural areas of Western Australia were described using Langmuir and Freundlich equations. The Langmuir P maximum (xm) ranged from 11 to 2132 �g g-1 soil and the Freundlich k coefficient ranged from 1 to 1681. Clay content, DCB Fe and Al, oxalate Fe and AL, and pyrophosphate Al were positively related to xm and k. By using stepwise regression analysis, the combination of DCB and oxalate-soluble A1 predicted more than 75% Of the variation in the P sorption coefficients. Reactive Al compounds may thus be responsible for much of the P sorption by these soils. Soil pH in 1 M NaF (pH 8.2), which is normally used for the detection of allophanic material, was strongly related to the P sorption coefficients and might therefore be used as a quick test for predicting the P sorption capacity of soils.
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Hamza, M. A., i W. K. Anderson. "Improving soil physical fertility and crop yield on a clay soil in Western Australia". Australian Journal of Agricultural Research 53, nr 5 (2002): 615. http://dx.doi.org/10.1071/ar01099.
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In the low rainfall area of Western Australia, clay soils with massive soil structure form a major part of the area sown to wheat. Yield increases on such soils have been poor in the last decade compared with those on other soil types. An experiment was conducted over 4 years (1997–2000) using a factorial combination of soil ripping to 0.4 m, application of commercial grade gypsum at 2.5 t/ha, and addition of complete nutrients based on soil test each year. All crop residues were retained after harvest and returned to the soil. The experiment was conducted in a wheat–field pea rotation at Merredin, WA. Soil water infiltration rate, soil strength, bulk density, water-stable aggregates, cation exchange capacity, and wheat yields were measured. Grain yields of wheat and field peas were increased by deep ripping, the addition of gypsum, or the addition of complete nutrients in some years. The main treatment effects on yield were additive, as significant interactions between the treatments on yield were seldom found. However, all the main treatments also significantly improved many of the soil physical properties related to crop growth. In 2000, 4 years after the treatments were applied, soil water infiltration rate was increased by more than 200%, strength of the topsoil decreased by around 1600 kPa, and soil bulk density decreased by 20%. Gypsum application increased water-stable aggregates, but soil mixing caused by deep ripping reduced them. The combination of soil ripping and gypsum application in the presence of complete nutrients and annual return of crop residues to the soil is suggested to improve crop grain yield and soil physical fertility on a range of Western Australian soils.
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French, Robert J., i Bevan J. Buirchell. "Lupin: the largest grain legume crop in Western Australia, its adaptation and improvement through plant breeding". Australian Journal of Agricultural Research 56, nr 11 (2005): 1169. http://dx.doi.org/10.1071/ar05088.
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Between 500 000 and 1 000 000 tonnes of narrow-leafed lupins (Lupinus angustifolius L.) are produced in Western Australia each year. It has become the predominant grain legume in Western Australian agriculture because it is peculiarly well adapted to acid sandy soils and the Mediterranean climate of south-western Australia. It has a deep root system and root growth is not reduced in mildly acid soils, which allows it to fully exploit the water and nutrients in the deep acid sandplain soils that cover much of the agricultural areas of Western Australia. It copes with seasonal drought through drought escape and dehydration postponement. Drought escape is lupin’s main adaptation to drought, and has been strengthened by plant breeders over the past 40 years by removal of the vernalisation requirement for flowering, and further selection for earlier flowering and maturity. Lupin postpones dehydration by several mechanisms. Its deep root system allows it to draw on water from deep in the soil profile. Lupin stomata close to reduce crop water demand at a higher leaf water potential than wheat, but photosynthetic rates are higher when well watered. It has been proposed that stomata close in response to roots sensing receding soil moisture, possibly at a critical water potential at the root surface. This is an adaptation to sandy soils, which hold a greater proportion of their water at high matric potentials than loamy or clayey soils, since the crop needs to moderate its water use while there is still sufficient soil water left to complete its life cycle. Lupin has limited capacity for osmotic adjustment, and does not tolerate dehydration as well as other crops such as wheat or chickpea. Plant breeding has increased the yield potential of lupin in the main lupin growing areas of Western Australia by 2–3 fold since the first adapted cultivar was released in 1967. This has been due largely to selecting earlier flowering and maturing cultivars, but also to improved pod set and retention, resistance to Phomopsis leptostromiformis (Kühn) Bubák, and more rapid seed filling. We propose a model for reproductive development in lupin where vegetative growth is terminated in response to receding soil moisture and followed by a period in which all assimilate is devoted to seed filling. This should allow lupin to adjust its developmental pattern in response to seasonal conditions to something like the optimum that mathematical optimal control theory would choose for that season. This is the type of pattern that has evolved in lupin, and the task of future plant breeders will be to fine-tune it to better suit the environment in the lupin growing areas of Western Australia.