Fourie, AB, Tibbett, M, Worthington, T & King, AE 2008, 'Quantifying the Effect of Substrate Compaction on Root Development in Cover Systems', in AB Fourie, M Tibbett, I Weiersbye & P Dye (eds), Mine Closure 2008: Proceedings of the Third International Seminar on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 27-34, https://doi.org/10.36487/ACG_repo/852_4
Vegetation is understandably an integral component of the cover systems used on most tailings and waste
rock disposal facilities. The soil in these covers is usually placed and spread using earthmoving equipment
such as trucks, scrapers, dozers and front-end loaders. Trafficking of this equipment can easily result in a
high degree of compaction of the cover soil, which may compromise the ability of roots to develop laterals or
penetrate to adequate depth. Poor root development may curtail the vegetation survival and growth, and
thus reduce the effectiveness of the cover system.
Soil was collected from the stockpile of a candidate cover soil at a tailings storage site in Western Australia.
The soil was compacted according to the relevant Australian Standard in 50 cm long, 10 cm diameter PVC
growth columns. Three compaction configurations were used, namely high, low and stratified, in a
replicated root penetration experiment. Pre-germinated seeds of Acacia celastrifolia were planted into each
column and grown in a temperature regulated glasshouse facility. At 40 days and 60 days after detection of
first growth, soil was extruded from the cylinders and the root architecture defined using a WinRHIZO
scanner and software.
The paper illustrates that the (limited) available literature on the effect of compaction density on root
development is simplistic and can be unnecessarily restrictive if adhered to blindly. The importance of
working within a framework that contextualizes the degree of compaction, such as is used in engineering
earthworks, is shown to be a key factor in interpreting the results of this type of study.
Australian Standard AS1289. Methods of Testing Soil for Engineering Purposes.
Blake, G.R., Nelson, W.W. and Allmaras, R.R. (1976) Persistence of subsoil compaction in a mollisol. Soil Sci. Soc.
Am. J., 40: pp. 943-947.
Corcoran, P.T. and Gove, D.S. (1985) Understanding the mechanics of track traction. Proc. Int. Conf. on Soil
Dynamics, 17-19 June, Auburn University, Auburn, Alabama, U.S.A., pp. 664-678.
Dumbeck, G. (1984) Influence of extremely high vehicular loads on soil structure and root development. Mitt. Dtsch.
Bodenkundl. Ges., 40, pp. 61-62 (in German).
Hakansson, I., Voorhees, W.B. and Riley, H. (1988) Vehicle and wheel factors influencing soil compaction and crop
response in different traffic regimes. Soil and Tillage Research, 11: pp. 239-282.
Hamza, M.A. and Anderson, W.K. (2005) Soil compaction in cropping systems - a review of the nature, causes and
possible solutions, Soil and tillage research, 82, pp. 121-145.
Harrison, D.F., Cameron, K.C. and McLaren, R.G. (1994) Effects of subsoil loosening on soil physical-properties,
plant-root growth, and pasture yield, New Zealand Journal of Agricultural Research, 37, pp. 559-567.
Henderson, C.W.L. (1989) Using a penetrometer to predict the effects of soil compaction on the growth and yield of
wheat on uniform, sandy soils, Australian Journal of Agricultural Research, 40, pp. 497-508.
Renault, P. and Stengel, P. (1994) Modeling oxygen diffusion in aggregated soils, 1. Anaerobiosis inside the aggregates,
Soil Science Society of America Journal, 58, pp. 1017-1023.
Rokich, D.P., Meney, K.A., Dixon, K.W. and Sivasithamparam, K. (2001) The impact of soil disturbance on root
development in woodland communities in Western Australia, Australian Journal Of Botany, 49, pp. 169-183.
Scott, C.R. (1975) An introduction to soil mechanics and foundations. Applied Science Publishers.
Siegel-Issam, C.M., Burger, J.A., Powers, R.F., Ponder, F. and Patterson, S.C. (2005) Seedling Root Growth as a
Function of Soil Density and Water Content. Soil Science Society of America Journal; Jan/Feb 2005, 69, 1,
Soane, B.D. and Van Ouwerkerk C. (1980) The role of field traffic studies in soil management research, Soil and
Tillage Research, 1, pp. 205-206.