Phosphorus distribution in soils from Australian dairy and beef rearing pastoral systems
- Adeloju, Samuel, Webb, Benjamin, Smernik, Ronald
- Authors: Adeloju, Samuel , Webb, Benjamin , Smernik, Ronald
- Date: 2016
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 6, no. 2 (2016), p. 1-19
- Full Text:
- Reviewed:
- Description: The influence of soil type and management practices on P distribution in soils from Australian dairy and beef rearing pastoral systems has been investigated by chemical measurements and phosphorus-31 (31P) nuclear magnetic resonance (NMR) spectroscopy. The amount and forms of P within the soil profile varied with soil type, with the acidic red Ferrosols containing relatively high orthophosphate concentrations, averaging 72.2% compared with 66.8% for Dermosols, under similar management conditions. Soil from Sodosol sites which received less fertiliser P addition had the lowest orthophosphate concentration with only 57.6%. In contrast, relatively high proportions of organic P were found in soil samples from unfertilised Sodosol sites. On average, soil from Sodosol sites contained 37.5% organic P (combined monoester P and diester P), while those from Dermosol and Ferrosol sites contained 31.7% and 25.8%, respectively. Of these, the highest monoester phosphate proportions of 44.6% (site M3) and 46.4% (site M4) were found in Sodosol sites with no recent P inputs, but the highest proportion of diester phosphate (5.7%) was found in an unclassified grey sandy loam Dermosol. The higher organic P concentrations in soil from Sodosol sites may be associated with more regular moisture input from both rainfall and boarder-check (flood) irrigation. The highest level of pyrophosphate (8.5%) was also found in a grey/yellow Sodosol. Overall, the results indicate that P speciation in the Australian soils is strongly influenced by soil type, fertiliser P application rate and timing, and moisture variations. © 2016 by the authors; licensee MDPI, Basel, Switzerland.
- Authors: Adeloju, Samuel , Webb, Benjamin , Smernik, Ronald
- Date: 2016
- Type: Text , Journal article
- Relation: Applied Sciences (Switzerland) Vol. 6, no. 2 (2016), p. 1-19
- Full Text:
- Reviewed:
- Description: The influence of soil type and management practices on P distribution in soils from Australian dairy and beef rearing pastoral systems has been investigated by chemical measurements and phosphorus-31 (31P) nuclear magnetic resonance (NMR) spectroscopy. The amount and forms of P within the soil profile varied with soil type, with the acidic red Ferrosols containing relatively high orthophosphate concentrations, averaging 72.2% compared with 66.8% for Dermosols, under similar management conditions. Soil from Sodosol sites which received less fertiliser P addition had the lowest orthophosphate concentration with only 57.6%. In contrast, relatively high proportions of organic P were found in soil samples from unfertilised Sodosol sites. On average, soil from Sodosol sites contained 37.5% organic P (combined monoester P and diester P), while those from Dermosol and Ferrosol sites contained 31.7% and 25.8%, respectively. Of these, the highest monoester phosphate proportions of 44.6% (site M3) and 46.4% (site M4) were found in Sodosol sites with no recent P inputs, but the highest proportion of diester phosphate (5.7%) was found in an unclassified grey sandy loam Dermosol. The higher organic P concentrations in soil from Sodosol sites may be associated with more regular moisture input from both rainfall and boarder-check (flood) irrigation. The highest level of pyrophosphate (8.5%) was also found in a grey/yellow Sodosol. Overall, the results indicate that P speciation in the Australian soils is strongly influenced by soil type, fertiliser P application rate and timing, and moisture variations. © 2016 by the authors; licensee MDPI, Basel, Switzerland.
- Schefe, Cassandra, Barlow, Kirsten, Robinson, Nathan, Crawford, Douglas, McLaren, Timothy, Smernik, Ronald, Croatto, George, Walsh, Ronald, Kitching, Matt
- Authors: Schefe, Cassandra , Barlow, Kirsten , Robinson, Nathan , Crawford, Douglas , McLaren, Timothy , Smernik, Ronald , Croatto, George , Walsh, Ronald , Kitching, Matt
- Date: 2015
- Type: Text , Journal article
- Relation: Soil Research Vol. 53, no. 6 (2015), p. 662-676
- Full Text: false
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- Description: Pasture-based animal production systems, which occupy a significant proportion of the landscape in Victoria, Australia, have historically been nutrient-limited, with phosphorus (P) often the most limiting nutrient. The Permanent Top-Dressed (PTD) pasture experiment was established in 1914 at the Rutherglen Research Station, Victoria, to investigate the management of this deficiency. The main objective of the PTD experiment was to demonstrate the value of adding P fertiliser at two rates to increase pasture productivity for lamb and wool production. We report on the status of the PTD soils after 100 years, investigating the long-term implications of continuous grazing and fertiliser management (0, 125 and 250kg/ha of superphosphate every second year) of non-disturbed pasture. We investigated the long-term effects of P fertiliser on the forms and distribution of P and other relevant soil parameters. In the fertilised treatments, P has accumulated in the surface soils (0-10cm) as both orthophosphate and organic P, with an Olsen P of 16-21mg P/kg, which is non-limiting for pasture production. In the treatment with 250kg superphosphate, there has also been movement of P down through the soil profile, probably due to the high sand content of the surface soil and the transfer through the profile of small quantities of water-soluble P and P bound to organic ligands. Over time, the site has continued to acidify (surface 0-10cm); the soil acidity combined with aluminium (Al) concentrations in the fertilised treatments approach a level that should impact on production and where broadcast lime would be recommended. After 100 years of non-disturbed pasture, the surface soils of these systems would be in a state of quasi-equilibrium, in which the fertilised systems have high levels of carbon (C), nitrogen, P and exchangeable Al. The continued stability of this system is likely dependent upon maintaining the high C status, which is important to nutrient cycling and the prevention of Al phytotoxicity. There are two risks to this system: (i) the declining pH; and (ii) soil disturbance, which may disrupt the equilibrium of these soils and the bio-chemical processes that maintain it. © CSIRO 2015.
Changes in the chemistry of sedimentary organic matter within the Coorong over space and time
- Krull, Evelyn, Haynes, Deborah, Lamontagne, Sebastien, Gell, Peter, McKirdy, David, Hancock, Gary, McGowan, Janine, Smernik, Ronald
- Authors: Krull, Evelyn , Haynes, Deborah , Lamontagne, Sebastien , Gell, Peter , McKirdy, David , Hancock, Gary , McGowan, Janine , Smernik, Ronald
- Date: 2009
- Type: Text , Journal article
- Relation: Biogeochemistry Vol. 92, no. 1-2 (2009), p. 9-25
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- Description: Like many other coastal systems across the world, the Coorong lagoonal ecosystem (South Australia) has degraded over the last 100 years; in this case as a result of extensive regulation and diversions of water across the Murray-Darling Basin following European settlement. To evaluate whether the sources of organic matter (OM) supporting its food-web have changed since the inception of water management and barrage construction, sedimentary OM was characterised in cores spanning the Coorong’s salinity gradient at depths representative of the last 100 years over which the management alterations to river and estuarine flow were most marked. Detailed 210Pb, 137Cs and Pu dating in conjunction with palaeolimnological data (Pinus pollen) allowed for the reconstruction of the timing of substantial changes observed in the composition of the OM, most of which occur during the early 1950s, concurrent with management-related variations in water flow and salinity. Negative shifts in
- Authors: Krull, Evelyn , Haynes, Deborah , Lamontagne, Sebastien , Gell, Peter , McKirdy, David , Hancock, Gary , McGowan, Janine , Smernik, Ronald
- Date: 2009
- Type: Text , Journal article
- Relation: Biogeochemistry Vol. 92, no. 1-2 (2009), p. 9-25
- Full Text:
- Description: Like many other coastal systems across the world, the Coorong lagoonal ecosystem (South Australia) has degraded over the last 100 years; in this case as a result of extensive regulation and diversions of water across the Murray-Darling Basin following European settlement. To evaluate whether the sources of organic matter (OM) supporting its food-web have changed since the inception of water management and barrage construction, sedimentary OM was characterised in cores spanning the Coorong’s salinity gradient at depths representative of the last 100 years over which the management alterations to river and estuarine flow were most marked. Detailed 210Pb, 137Cs and Pu dating in conjunction with palaeolimnological data (Pinus pollen) allowed for the reconstruction of the timing of substantial changes observed in the composition of the OM, most of which occur during the early 1950s, concurrent with management-related variations in water flow and salinity. Negative shifts in
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