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Graminae
Common names
Soft spinifex (Australia).
Description
A somewhat glutinous tussock grass. Leaves rigid, spreading,
sharp- pointed, the sheaths sometimes woolly. Panicle narrow, 8-15 cm long.
Spikelets on slender pedicels, 8-12 mm long; outer glumes 6-8 mm long,
glabrous, five- to seven-nerved; flowering glume purplish, cut halfway
down into three broad, three- nerved lobes, silky-villous toward the base.
Grazing management
Rotational spelling of paddocks during the wet season every
three to four years will allow the softer, edible, associated plants to
build up a seed reserve to ensure their continuing presence. Burn every
three to four years at the end of the dry season or after the first storms
to remove old, dry, spiny material and promote soft growth for grazing.
Burning after the wet season destroys the softer edible plants. Uncontrolled
grazing leads to complete removal of vegetation, increasing erosion and
permanently reducing productivity (Bishop, 1973).
Response to fire
Annual burning followed by continuous heavy stocking increases
the proportion of spinifex at the cost of associated softer edible plants.
Palatability
Not very palatable, but eaten in the absence of other forage.
Chemical analysis and
digestibility
In the dry matter, Siebert, Newman and Nelson (1968) recorded
a range of 2.8-4.3 percent crude protein, 27.6-35.8 percent crude fibre,
6.3-9.8 percent ash, 1-13.7 percent ether extract and 48.1-50.6 percent
nitrogen-free extract, for two samples of dry material. One analysis of
young regrowth (about 18 cm high after burning) yielded 7 percent crude
protein in the dry matter.
Natural habitat
Sand dunes and sand plains.
Economics
Soft spinifex is the main constituent of the tussocky spinifex
grasslands in arid Australia. It thrives on sand dunes, rocky slopes of
laterized desert sandstone ranges and on solodic soils on the dry tropical
plains. It is usually burnt by aboriginal tribes; the resin obtained from
the burning material has been used to glue handles on stone axes and other
implements. After burning, the young regrowth is grazed by cattle and sheep.
Further reading
Bishop, 1973.
Response to fertilizers
T. pungens does not respond to fertilizers. At Yalleroi in
central Queensland the dry-matter content of spinifex in the natural pasture
fell from 78 percent unfertilized to 63 percent when fertilized with NPK,
whereas that of other perennials and annual grasses increased (Edye et
al., 1964).
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