1887
Volume 31, Issue 1-2
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

The ability to rapidly and accurately determine the vertical and spatial distribution of soil salinity at a farm or paddock scale is extremely important for land managers and researchers involved in managing land salination. Knowledge of current (shallow) soil salinity levels is required to make informed short-term management decisions as to what pasture, crop or tree species will be the most productive, or should be grown to minimise surface soil salination. Prognosis of future (deeper) salinity development is required for longer-term management. Hence, characteristics of regolith salt store and groundwater depth are essential information. The vertical distribution of salt throughout the regolith is also very important at the regional scale and for calibrating larger-scale airborne EM mapping systems.

Accurate site assessment using soil sampling and laboratory analysis is time consuming, expensive and can be highly variable because of large spatial variability compared with sample size and practical sampling density. Clearly, an accurate and efficient system of salinity mapping using portable ground-based geophysical instruments is required.

The Geonics EM38 and EM31 instruments have been routinely used to map soil salinity. Recently, automated ground-based data acquisition and real-time mapping systems have been developed. In the past, most use has been made of the instruments’ relative readings. However, continued calibration in variable terrain will allow for more practical and absolute use to be made of readings.

The Geonics EM34 and EM39 instruments have also been used to determine salinity profiles to depth; however, usually in experimental situations. They have the potential to replace deep drilling (EM34) and drill-sample assay (EM39), and have been used to evaluate airborne EM systems.

We have reviewed the use of the four Geonics instruments for salinity investigations and present over thirty calibrations with soil salinity from various terrains in southwestern Australia and compare them with calibrations from eastern Australia. We found that the instruments are reliable and the information they generate is reproducible. In all situations studied, salinity was the dominant contributor to EM response. However, soil type, moisture and temperature can have secondary contributions, which may be more important when EM is used to assess and predict plant response to salinity. We show that for practical purposes ground-based EM can be confidently used in salinity mapping.

© 2000 ASEG
Loading

Article metrics loading...

/content/journals/10.1071/EG00249
2000-03-01
2026-01-20

  • From This Site

    /content/journals/10.1071/EG00249
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Bennett, D.L. and George, R.J., 1995, Using the EM38 to measure the effect of soil salinity on Eucalyptus globulus in south-western Australia: Agric. Water Management, 27, 69-86.
  2. Bennett, D.L. and George, R.J., 1996, River Red Gums for farm forestry on saline and waterlogged land in south western catchments of Western Australia: Fourth National Conference on the Productive Use of Saline Lands, Albany, Western Australia.
  3. Bennett, D.L, George, R.J. and Ryder, A.T., 1995, Soil salinity assessment using the EM38: Field operating instructions and data interpretation: Miscellaneous Publication 4/95, Western Australian Department of Agriculture.
  4. Cannon, M.E., McKenzie, R.C. and Lachapelle, G., 1994, Soil salinity mapping with electromagnetic induction and satellite-based navigation methods: Can. J. Soil Sci., 74, 335-344.
  5. Cook, P.G., Hughes, M.W, Walker, G.R., and Allison, G.B., 1992, The calibration of frequency domain electromagnetic induction meters and their possible use in recharge studies: J. Hydrol., 13, 201-209
  6. Corwin D.L. and Rhoades, 1982, An improved technique for determining soil electrical conductivity-depth relations from above ground measurements: Soil Sci. Soc. Am. J., 46, 517-520.
  7. de Broekert, P., 1996, An assessment of airborne electromagnetics for hydrogeological interpretation in the wheatbelt, Western Australia: Resource Management Technical Report No. 151, Agriculture Western Australia.
  8. Engel, R., McFarlane, D.J. and Street, G.J., 1989, Using geophysics to define recharge and discharge areas associated with saline seeps in south-western Australia, in Sharma, M.L., Ed., Groundwater Recharge: A.A. Balkema.
  9. Ferdowsian, R., George, R. Lewis, F., Mcfarlane, D., Short, R. and Speed, R., 1996, The extent of dryland salinity in Western Australia: Fourth National Conference on the Productive Use of Saline Lands. Albany, Western Australia.
  10. Ferdowsian, R. and Greenham, K., 1992, Integrated catchment management, Upper Denmark catchment: Division of Resource Management Technical Report 130, Department of Agriculture, Western Australia.
  11. George, R.J., 1998, Evaluation of airborne geophysics for catchment management, Toolibin,Western Australia: Agriculture, Fisheries and Forestry - Australia and the National Dryland Salinity Program.
  12. George, R.J. and Bennett, D.L., 1999, Root zone electromagnetic systems explain variations in soil salinity: Irrigation ‘99 Conference, Perth, Irrigation Association of Australia CD.
  13. George, R.J., Nulsen, R.A., Ferdowsian, R. and Raper, P., 1999, Interactions between trees and groundwaters in recharge and discharge areas - a survey of Western Australian sites: Agric. Water Management, 39, 91-113
  14. George, P.R. and Wren, B.A., 1985, Crop tolerance to soil salinity: Technote No. 6/85, Western Australia Department of Agriculture.
  15. Halvorson, A.D., Rhoades, J.D. and Ruele, C.A., 1977, Soil salinity four-electrode conductivity relationships for the soils of the northern Great Plains: Soil. Sci. Soc. Am. J., 41, 966-971.
  16. McFarlane D.J. and George, R.J., 1992, Factors affecting dryland salinity in two wheatbelt catchments in Western Australia: Aust. J. Soil Res., 30, 85-100.
  17. McFarlane D.J. and Ryder, A.T., 1990, Salinity and waterlogging on Esperence Downs Research Station: DRM Technical Report No. 108,West Australian Department of Agriculture.
  18. McNeill, J.D., 1980a, Electrical conductivity of soils and rocks: Tech. Note TN-5, Geonics Pty. Ltd., Ontario, Canada.
  19. McNeill, J.D., 1980b, Electromagnetic terrain conductivity measurement at low induction numbers: Tech. Note TN-6, Geonics Pty. Ltd., Ontario, Canada.
  20. McNeill, J.D., 1990, EM39 - borehole conductivity logger operating manual: Geonics Pty. Ltd., Ontario, Canada.
  21. Norman, C.P., 1990, Training manual for the use of the EM38 for soil salinity appraisal: Technical Report No. 181, Department of Agriculture and Rural Affairs.
  22. Norman, C.P. and Heslop, K., 1991, Soil salinity survey of the Boort/West of Loddon salinity management plan area: Research Report No. 125, Department of Agriculture, Victoria.
  23. Norman, C.P., Lyle, C.W., Hueperman, A.F. and Poulton, D., 1988, Pyramid Hill Irrigation Area soil salinity report: Research Report Series no. 80, Victoria Department of Agriculture and Rural Affairs.
  24. Nulsen, R., 1981, Critical depth to saline groundwater in non-irrigated situations: Austral. J. Soil Res., 19, 83-86.
  25. Rhoades, J.D., Lesch, S.M., LeMert, R.D. and Alves, W.J., 1997, Assessing irrigation/drainage/salinity management using spatially referenced salinity measurements: Agric. Water Management 35, 147-165.
  26. Richards, L.A., 1954, Diagnostics and improvement of saline and alkali soils: Handbook No. 60, United States Department of Agriculture.
  27. Slavich, P.G. and Read, B.J., 1984, Assessment of electromagnetic induction measurements of soil salinity for indication of crop response, in: Humphries, E., Ed., Rootzone limitations in Clay Soils. Soil Science Society, Riverina Branch.
  28. Smith, A.D., George, R.J., Scott, P.R, Bennett, D.L., Rippon, R.J., Orr, G.J. and Tille, P.J., 1998, Results of investigations into the groundwater response and productivity of high water use agricultural systems, summary of all sites: Agriculture Western Australia Resource Management Technical Report 179.
  29. Speed, R.J., 1998, Evaluation of airborne geophysics for catchment management, Chapman Valley,Western Australia: Agriculture, Fisheries and Forestry - Australia and the National Dryland Salinity Program.
  30. Speed, R.J. and Simons, J.A., 1992, Deep drains - a case study: Resource Management Technical Report No. 151, Western Australia Department of Agriculture.
  31. Williams, B.G. and Baker, G.C., 1982, An improved induction technique for reconnaissance surveys of salinity hazards: Austral. J. Soil. Res., 20, 107-118.
  32. Williams, B.G. and Hoey, D., 1987, The use of electromagnetic induction to detect the spatial variability of the salt and clay contents of soils: Austral. J. Soil Res., 25, 21-27.
/content/journals/10.1071/EG00249
Loading
  • Article Type: Research Article
Keyword(s): Electromagnetics; EM31; EM34; EM38; EM39; land management; salinity

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error