TITLE:
Availability of Residual and/or Applied Inorganic Phosphorus for Sugarcane Uptake and Growth in a Post-Mined Reconstituted Soil
AUTHORS:
Corlina Margaretha Van Jaarsveld, Godfrey Elijah Zharare, Michiel Adriaan Smit, Christiaan Cornelius Du Preez
KEYWORDS:
Nutrient Uptake, Soil Rehabilitation, Surface Mining, Water Table, Mineral Sand Mining
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.10 No.11,
November
22,
2022
ABSTRACT: Mineral sands mining is worldwide an environmental
issue and also at the Hillendale mine in KwaZulu-Natal, South Africa. The
post-mined soil is to be rehabilitated to sugarcane cropping. One of the
concerns with the post-mined soil which is reconstituted with a 70:30 mixture
of sand: slimes (silt-plus-clay fraction), is its low phosphorus (P) status,
which could be limiting for optimum sugarcane production. A field experiment
was conducted on a reconstituted soil at Hillendale to establish the
availability of either residual or applied inorganic P to the plant and first
ratoon sugarcane crop. Four treatments were evaluated including those where P
fertilizer was omitted, applied at half the recommended rate or introduced
equal to the recommended rate according to chemical analysis of the soil. In
the fourth treatment, no fertilizer was applied at all, whereas nitrogen
(N) and potassium (K) were added at recommended rates in the first three
treatments. Phosphorus application had a
significant effect on sugarcane fractional light interception and aboveground biomass
yield of the plant and first ratoon crops, and stalk length and diameter of the
first ratoon crop. Pol, brix, purity and fibre content and tiller number were
not affected by P application. The application of P increased the foliar N, P,
K, calcium (Ca), magnesium (Mg) and sulphur (S) contents of both crops.
However, foliar N, P and K were deficient in the first ratoon crop even in the
case where fertilizer was applied at the recommended rates, which could have
been because of waterlogging. The possible effect of waterlogging on P uptake
needs to be addressed in future studies in this reconstituted soil.