- Title
- 100 Years of superphosphate addition to pasture in an acid soil - Current nutrient status and future management
- Creator
- Schefe, Cassandra; Barlow, Kirsten; Robinson, Nathan; Crawford, Douglas; McLaren, Timothy; Smernik, Ronald; Croatto, George; Walsh, Ronald; Kitching, Matt
- Date
- 2015
- Type
- Text; Journal article
- Identifier
- http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/97903
- Identifier
- vital:10262
- Identifier
-
https://doi.org/10.1071/SR14241
- Identifier
- ISSN:1838-675X
- Abstract
- 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.
- Publisher
- CSIRO
- Relation
- Soil Research Vol. 53, no. 6 (2015), p. 662-676
- Rights
- Copyright © CSIRO 2015.
- Rights
- This metadata is freely available under a CCO license
- Subject
- MD Multidisciplinary; 31P NMR.; Acidification; Fertiliser; Long-term field experiment; MIR; Organic phosphorus; PTD
- Reviewed
- Hits: 6459
- Visitors: 5775
- Downloads: 2
| Thumbnail | File | Description | Size | Format |
|---|