Influence of sample depth on extractable nutrient concentrations, pH and the phosphorus buffering index of pasture soils in south-eastern Australia
J. R. Coad A C , L. L. Burkitt A and C. J. P. Gourley BA Tasmanian Institute of Agricultural Research, University of Tasmania, PO Box 3523, Burnie, Tas. 7320, Australia.
B Department of Primary Industries, 1301 Hazeldean Rd, Ellinbank, Vic. 3821, Australia.
C Corresponding author. Email: Jessica.Coad@utas.edu.au
Australian Journal of Soil Research 48(4) 355-360 https://doi.org/10.1071/SR09104
Submitted: 5 June 2009 Accepted: 13 January 2010 Published: 16 June 2010
Abstract
Pasture soils of mainland Australia are routinely sampled to a depth of 100 mm, whereas pasture soils of Tasmania and New Zealand are sampled to a depth of 75 mm. Despite this difference, there are no published studies to allow accurate conversion between the 2 sampling depths. This study was undertaken to examine the effect of soil sample depth (75 and 100 mm) on soil nutrient analyses: Olsen phosphorus (P), Colwell P, Colwell potassium (K), KCl40 sulfur (S), pH (H2O and CaCl2), and P buffering index (PBI+ColP). Our findings suggest that on most soil types, Olsen P, Colwell P, and Colwell K soil test results could use a generic factor of 1.17 when converting between 75 and 100 mm samples. More detailed equations including direct or indirect measures of soil texture and P sorption capacity were also determined. We found there was no significant difference in P and K concentrations between the different depths in soils which had very low P sorption capacities, high sand contents, and were located in high rainfall zones. Additionally, soil sampling depth generally had no effect on extractable S concentrations, pH, or PBI+ColP, and therefore no conversion is recommended for these soil tests for any soil type.
Additional keywords: soil sampling depth, phosphorus, potassium, sulphur, pH, PBI+ColP, nutrient stratification.
Acknowledgments
We thank John and Joan Van Loon, Paul and Bernadette Bennett, Tim Bennett and family, David Riddoch and Jason Hall, Nick Smith and Claudia Greene, and staff at TIAR Dairy Research Facility (especially Lesley Irvine) for allowing us to have experimental sites on their properties. The core project was funded by Dairy Australia, Impact Fertilisers Australia Proprietary Limited, and Incitec Pivot Limited. Thanks also to Dr Richard Rawnsley and Dr Ross Corkery for statistical assistance, as well as Dr Leigh Sparrow for input into the manuscript.
Blair GJ,
Chinoim N,
Lefroy RDB,
Anderson GC, Crocker GJ
(1991) A soil sulfur test for pastures and crops. Australian Journal of Soil Research 29, 619–626.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Burkitt LL,
Gourley CJP,
Hannah MC, Sale PWG
(2006) Assessing alternative approaches to predicting soil phosphorus sorption. Soil Use and Management 22, 325–333.
Burkitt LL,
Gourley CJP,
Sale PMG,
Uren NC, Hannah MC
(2001) Factors affecting the change in extractable phosphorus following the application of phosphatic fertiliser on pasture soils in southern Victoria. Australian Journal of Soil Research 39, 759–771.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Burkitt LL,
Gourley CJP, Sale PWG
(2004) Phosphorus auditing cannot account for all of the phosphorus applied to different pasture soils. Australian Journal of Soil Research 42, 89–98.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Burkitt LL,
Moody PW,
Gourley CJP, Hannah MC
(2002) A simple phosphorus buffering index for Australian soils. Australian Journal of Soil Research 40, 497–513.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Colwell JD
(1963) The estimation of the phosphorus fertilizer requirements of wheat in southern New South Wales by soil analysis. Australian Journal of Experimental Agriculture and Animal Husbandry 3, 190–197.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Dougherty WJ,
Nash DM,
Chittleborough DJ,
Cox JW, Fleming NK
(2006) Stratification, forms, and mobility of phosphorus in the topsoil of a Chromosol used for dairying. Australian Journal of Soil Research 44, 277–284.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Gillman GP, Sumpter EA
(1986) Modification to the compulsive exchange method for measuring exchange characteristics of soils. Australian Journal of Soil Research 24, 61–66.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Humphreys J,
Tunney H, Duggan P
(1998) Soil phosphorus determination using three extraction procedures, the effect of sampling depth and comparison of phosphorus fertiliser recommendations for grassland. Irish Journal of Agricultural and Food Research 37, 29–38.
|
CAS |
Lewis DC,
Clarke AL, Hall WB
(1981) Factors affecting the retention of P applied as superphosphate to the sandy soils in south-eastern South Australia. Australian Journal of Soil Research 19, 167–174.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Lewis DC,
Clark AL, Hall WB
(1987) Accumulation of plant nutrients and changes in soil properties of sandy soils under fertilized pastures in south-eastern South Australia. I. Phosphorus. Australian Journal of Soil Research 25, 193–202.
| Crossref | GoogleScholarGoogle Scholar |
Moody PW
(2007) Interpretation of a single-point P buffering index for adjusting critical levels of the Colwell soil P test. Australian Journal of Soil Research 45, 55–62.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Russell JS
(1960) Soil fertility changes in the long-term experimental plots at Kybybolite, South Australia. Australian Journal of Agricultural Research 11, 927–947.
|
CAS |
Schwertmann U
(1964) Differenzierung der eisenoxide des bodens durch photochemische extraktion mit sauer ammoniumoxalate-losung. Zeitschrift fur Pflanzenernahrung und Bodenkunde 105, 194–202.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Sharpley AN,
Smith SJ, Naney JW
(1987) Environmental impact of agricultural nitrogen and phosphorus use. Journal of Agricultural and Food Chemistry 35, 812–817.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Thompson ML
(1978) Selection of variables in multiple regression: Part 1. A review and evaluation. International Statistical Review 46, 1–19.
| Crossref | GoogleScholarGoogle Scholar |
Walkley A, Black A
(1934) An examination of the Degtjareff method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Science 37, 29–38.
| Crossref | GoogleScholarGoogle Scholar |
CAS |
Wheeler DM, Edmeades DC
(1995) Effect of depth and lime or phosphorus fertilizer applications on the soil solution chemistry of some New Zealand pastoral soils. Australian Journal of Soil Research 33, 461–476.
| Crossref | GoogleScholarGoogle Scholar |
CAS |