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Soil and water management of waterlogged and saline soils
D. Bakker1, G. Hamilton2, A. van-Burgel1, R. Hetherington1 and C. Spann3
Department of Agriculture Western Australia, 1Albany, 2Perth, 3Mt Barker, WA, Australia. Email: dbakker@agric.wa.gov.au
Abstract
The application of raised beds to reduce waterlogging in non-saline soils has been widely adopted in some areas of Victoria and Western Australia (WA). The application has now been extended to saline waterlogged land with the aim of eliminating waterlogging and reduce the salt levels and to improve the productivity in these areas. Three large experimental sites (40 – 60 ha) were installed in 2002 in areas in WA with a varying degree of salinity and waterlogging. Two forms of raised beds were constructed: raised beds a) with and b) without deep cultivation prior to bed forming. A control was used to assess the impact of the treatments. The spatial distribution of soil conductivity, biomass and yield data was collected at different times using an EM38, NDVI images and a yield monitor, respectively as well as more detailed soil moisture and salinity profiles. Soil conductivity, biomass and yield relationships were developed for each treatment using a relative yield and local neighbourhood approach to accommodate the large spatial variations in the yield. The results to date indicate a significant effect of the bed treatments on the yield due to the elimination of waterlogging but as yet little effect on the salt balance. Large fluctuations in salt levels over time and at different soil depths are related more to seasonal conditions and salt levels stored deeper in the profile rather than to the treatments.  
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