The response of wheat on acidic soil using lime-amended biosolids

Abstract

Agricultural soils throughout much of Australia, and particularly Western Australia commonly suffer from nutrient deficiencies and/or soil acidity. Plant growth can be reduced in acidic soils due to problems with aluminium toxicity, deficiencies of some nutrients and nodulation failure in legumes. The nutrient levels of soil can be improved by the addition of fertilisers, whereas the pH of acidic soils can be increased by the addition of products containing lime or dolomite.Lime-amended biosolids (LAB) is currently produced at the Subiaco Wastewater Treatment Plant, Perth Western Australia. The two-fold value of LAB as a source of nutrients for the growth and yield of wheat (Triticum aestivum) on an acidic soil in the central wheatbelt in agricultural Western Australia and for the neutralising value of the added lime was investigated over the 2005 season to assess the effect of LAB. Specifically, the investigation aimed to establish current LAB application rates to meet the required pH adjustment to sustain crop growth; establish maximum application rates to meet soil pH adjustment and nutrient requirement to sustain crop growth; and to establish the value of LAB from an agricultural perspective with the view of establishing a suitable monetary return.The benefit of the LAB in the first season of application appeared to be from the nutrient value of the recycled nutrients rather than that of the initial reduction in soil acidity. However, further data needs to be collected over subsequent years to ensure that LAB does not impact adversely on crop production or cause environment harm all of which may jeopardise the current market.