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Abstract
The chromosol soils of the Duri district range from highly to moderately degraded. The poorer
condition results in high overland flow, reduced plant available water, and can lead to greater
recharging of lower lying vertosol soils, which have a greater salt store and as a consequence of
recharge may result in salt mobilization. Application of fertilizer and sub-clovers on chromosols has
been analyzed to determine economic benefits on two properties in the Duri area. Using a low ($80)
and high ($130) pasture establishment cost for improving the grass- Danthonia spp dominated
chromosol soils. Total Farm Gross Margins (TFGM) were modeled (Hassall & Associates Pty Ltd.)
on a dominate (68%) degraded chromosol site (Site 1) and a vertosol dominated (25% chromosol) site
(Site 2). Results for Site 1 indicated that there was an increase in TFGM in subsequent years with a
low establishment cost. Increasing the establishment cost resulted in an initial decrease in TFGM, with
subsequent years leading to TFGM improvement. However, the degraded nature of this soil makes the
short term improvements highly unlikely. Site 2 has less potential for pasture improvement due to the
limited chromosol area within this property. However, result of the modeling indicate that under both
low and high establishment costs, depending upon seasonal conditions, it may take years before greater
returns are observed. In fact to warrant the investment a minimum carrying capacity of 3.5 DSE/ha at
Site 1 and 3.5 to 4.5 DSE/ha at Site 2 is required. Overall further investigation into remediation
options are needed, with farmer negotiation an important aspect of any recommendation.