Variation in soil properties on two partially revegetated saline scalds in south-eastern Australia
W. S. Semple A F , T. B. Koen B , D. J. Eldridge C , K. M. Düttmer D and B. Parker EA Department of Natural Resources, PO Box 53, Orange, NSW 2800, Australia.
B Department of Natural Resources, PO Box 445, Cowra, NSW 2794, Australia.
C Department of Natural Resources, c/- School of Biological, Earth and Environmental Sciences, University of NSW, Sydney, NSW 2052, Australia.
D School of Geography, University of NSW, Sydney, NSW 2052, Australia. Present address: PO Box A24, Sydney South, NSW 1235, Australia.
E Murrumbidgee Catchment Management Authority, PO Box 23, Yass, NSW 2582, Australia.
F Corresponding author. Email: bill.semple@dnr.nsw.gov.au
Australian Journal of Experimental Agriculture 46(10) 1279-1289 https://doi.org/10.1071/EA04129
Submitted: 5 July 2004 Accepted: 26 June 2005 Published: 13 September 2006
Abstract
During 1999 and 2000, topsoil properties were sampled on a 3 by 3 m grid at 2 saline scalds on the inland slopes of New South Wales (NSW): Bocobra (0.11 ha) and Rugby (0.12 ha). Variability was examined in terms of range, standard deviation and coefficient of variation, maps with interpolated ‘contours’, and variograms. High variability was evident in all soil properties. pH1:5 water ranged from 4.8 to 8.0 at Bocobra and 5.9 to 9.0 at Rugby. Spatial ‘highs’ were evident at both sites but Rugby, which was mostly neutral, had both highs (alkalinity) and lows (acidity). Electrical conductivity (EC1:5 water) ranged from 0.5 to 6.6 dS/m at Bocobra and 0.1 to 2.6 dS/m at Rugby and was expressed spatially as highs across the sites. Concentrations of soluble ions were highly variable with both highs and lows evident. Concentrations of sodium and magnesium at Bocobra were highly correlated with EC1:5 water. Variability in EC and pH were high in comparison with published data from much larger areas of non-saline soils. An indication of temporal variability was obtained by carrying out an electromagnetic induction survey on 2 occasions. Despite changes in spatial patterns over time, EMh and EMv values were highly correlated at 1 site but not at the other. Variogram analysis suggested that changes in some variables, e.g. soluble potassium, changed markedly over distances less than 3 m. For most variables, the full range of variability occurred over distances of 8–10 m, though for some, e.g. soluble calcium, a distance of around 19 m was indicated. Variability cannot be ignored when planning revegetation projects or experiments. Partly because of their temporal variability, electromagnetic induction survey results (which were not calibrated with soil profile ECs in this study) may not provide useful guidelines for strategic soil sampling nor for locating experimental plots on scalded saline sites. Consideration should also be given to testing variables other than EC, e.g. pH and calcium, which may also limit plant growth on saline scalds.
Acknowledgments
Mr and Mrs G. Yelland (Bocobra) and Mr P. Cooke (Rugby) provided on-going access to trial sites. Messrs A. Nicholson, A. Wooldridge and N. Henry carried out the EMI surveys. Ms D. Yu undertook the soil analyses of the Rugby samples. Dr W. King and colleagues in the Sustainable Grazing Systems project (Orange, NSW) provided unpublished pH and EC paddock data for analysis. Drs B. Murphy and B. Williams and Messrs A. Brown and A. Wooldridge assisted with result interpretation. Dr J. Corish and an anonymous referee provided constructive comments on the manuscript.
Álvarez-Rogel J,
Hernández J,
Ortiz Silla R, Alcaraz F
(1997) Patterns of spatial and temporal variations in soil salinity: example of a salt marsh in a semiarid climate. Arid Soil Research and Rehabilitation 11, 315–329.
(verified 9 June 2006)
Slavich PG, Petterson GH
(1993) Estimating the electrical conductivity of saturated paste extracts from 1:5 soil:water suspensions and texture. Australian Journal of Soil Research 31, 73–81.
| Crossref | GoogleScholarGoogle Scholar |
Verbyla AP,
Cullis BR,
Kenward MG, Welham SJ
(1999) Analysis of designed experiments and longitudinal data by using smoothing splines (with discussion). Applied Statistics 48, 269–312.
Viscarra Rossel RA, McBratney AB
(1998) Soil chemical analytical accuracy and costs: implications for precision agriculture. Australian Journal of Experimental Agriculture 38, 765–775.
| Crossref | GoogleScholarGoogle Scholar |
