Kotzé, H, Hattingh, R & Ballot, C 2008, 'Economical Viability of Rehabilitated Sugarcane Agriculture', in AB Fourie, M Tibbett, I Weiersbye & P Dye (eds), Mine Closure 2008: Proceedings of the Third International Seminar on Mine Closure
, Australian Centre for Geomechanics, Perth, pp. 705-714, https://doi.org/10.36487/ACG_repo/852_66
Surface mining of heavy minerals is conducted on the east coast of South Africa. The resultant disturbed
land is rehabilitated to sugarcane agriculture (its pre-mining land use) by capping the backfilled sand dunes
with a layer of a sand-slimes mixture. The required composition and thickness of this layer was modeled with
the predicted sugarcane yields as a primary output variable. Both the composition and thickness of the layer
are significant in determining the water-holding capacity of the reconstituted soil, which in turn is a
determining factor of the sugarcane yield. Sugarcane yield results obtained from the first harvest off
rehabilitated land compare favorably with the predicted model results - and typical yield numbers from
similar neighboring farming operations.
A business case model for rehabilitated farmland is used to determine the breakeven sugarcane yield for
positive revenue to cash cost. Since cane yield is, to an extent, a function of the sand-slimes layer thickness,
the resultant breakeven yield numbers are used to confirm the optimum layer thickness previously calculated
and reported from a soil perspective.
It is furthermore shown that like most other sugarcane producers, the rehabilitated land is sensitive to the
currently prevailing adverse economic conditions in the sugarcane industry.
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Hattingh, R., Linstrom, C., Krantz, R., Viljoen, C., Jovanovic, N. And Kotzé, H. (2007) Reconstituted soils: a
probabilistic approach to resolve aspects relating to the sustainability and economic viability of the rehabilitation
of mined lands, Mine Closure 2007, Santiago, Chile, October, pp. 261-271.
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