Assessing alternative agricultural lime sources
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The Department of Agriculture and Food, Western Australia (DAFWA) is currently advocating the use of various sources of liming agents in the agricultural regions of WA as a means of overcoming the agronomic limitations caused by the acidification of soils. Acidic soils occur in approximately 66% of WA’s broadscale farming regions and cause significant reductions in the potential yields of pastures and crops. Currently, approximately 500,000 tpa lime is used throughout WA with targets of up to 750,000 tpa being set by DAFWA. However, easily available and high quality lime sources are becoming rarer in WA and the demand for agricultural lime to treat soil acidity (especially when combined with the demand to ameliorate areas of Acid Sulfate Soils) is expected to outstrip supply in the very near future. Consequently, new sources of lime need to be found quickly. Recent research into the re-use of alumina refining by-products has concentrated on the nutrient retention abilities of these materials and their use in close proximity to the bauxite mines and refineries in WA’s south west (see details on the Alkaloam project). The use of these materials as liming agents has much broader implications throughout the entire WA agricultural region and has the potential to significantly improve the economic and environmental performance of agriculture across a number of regions and farming systems. Consequently, a series of field trials has now been set up in Merredin, Newdegate and Busselton where these potential new lime sources are being compared with traditional limes. The trials have only recently been established and final results are not expected until 2009. Contact Mark Rivers |
Up to 2000 soil samples are collected each year from the trial sites and analysed for a variety of parameters including pH. A Geoprobe percussive soil sampling rig is used to speed up the work. Trials at DAFWA’s Merredin and Newdegate Research Stations are installed in a strip fashion to allow seeding and harvesting using conventional agricultural cropping equipment. |