The spread of European settlement in coastal Queensland - The Great Barrier Reef: An Environmental History - page 50

(1997) demonstrated that application rates of nitrogenous fertiliser by Australian
sugar cane farmers increased since around 1910, with a very substantial increase
since 1950; that large increase in nitrogen application is shown in Figure 4.1(b) ,
which was accompanied by an increase in sugar cane yields (see also Garside
et al., 1997). However, the rates of nitrogen application increased more rapidly
than sugar cane yields, with the over-application of nitrogen in some cane-
producing districts, with the result that the levels of nutrient runoff to the
Great Barrier Reef increased. Figure 4.1(b) also shows the concurrent, although
smaller, increase in phosphorus application in Queensland since around 1920.
Phosphorus is another essential nutrient for sugar cane growth; and, without the
use of artificial fertilisers, soil phosphorus levels are generally low in uncultivated
or new sugar cane areas (Wood et al., 1997).
The soil analyses carried out by the QBSES showed that, in addition to
nitrogenous fertiliser, the acidic soils of the northern coastal districts - including
the Mossman, Cairns, Innisfail and Tully districts - required agricultural lime.
However, prior to 1945, the Mossman, Cairns, Innisfail, Ingham and Mackay
districts had only limited terrestrial sources of lime besides the inland sources
at Chillagoe and Ambrose, near Mount Larcom . 1 I n 1915, the QBSES reported
that efforts were being made to produce agricultural lime by pulverising coral
from the Great Barrier Reef; agricultural lime manufactured from coral had the
advantages of being comparatively cheap and chemically pure. The following
year, the QBSES found that interest in coral sand and coral lime was high among
sugar cane farmers, and that pulverising machines were already available on the
market; hence the QBSES advised farmers to use coral lime, chemical fertilisers
and green manures. By 1920, coral lime was being applied in the Mossman,
Goondi, Mourilyan and South Johnstone areas at a cost of £3 per ton for coral
sand and £4 per ton for burnt coral lime (Scriven, 1915, 1916, 1922). The removal
of coral from the Great Barrier Reef to produce agricultural and industrial lime is
one of the activities described in the narrative that follows (Chapter 11).
By 1914, the modern pattern of European occupation in coastal Queensland
and the dominant industries of grazing, sugar cane farming and mining had been
established. Closer settlement and further land clearance took place after the First
World War as additional lands were allocated to returning soldiers; for example,
lands at El Arish, near Tully, were occupied by discharged soldiers. Other newly-
opened lands included the rainforests of the Atherton-Evelyn Tableland, which
were cleared to open new grazing pastures, for maize cultivation and for dairying
(Birtles, 1988). The continued expansion of sugar cane cultivation in the two
subsequent decades, shown in Figure 4.1(a) , was accompanied by increasing
transformations of the Queensland environment: additional land clearance;
increases in fertiliser, insecticide and pesticide application rates; and ecological
changes. For example, in 1935, the cane toad ( Bufo marinus ) was introduced in
Queensland at the recommendation of the QBSES in an effort to combat cane
grub outbreaks, with severe ecological consequences (Griggs, 2005, 2007).