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
(https://papers.acg.uwa.edu.au/p/852_66_Kotze/)
Abstract: 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.