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The role of seed placement and gypsum in improving the establishment of spiny bluebush on scalded duplex soils in north-western Australia

B.H. Ward

Department of Agriculture, Carnarvon, Western Australia, 6701

Research and field observations of natural regeneration indicate that some positions for seed placement result in more germination and establishment than others(1). In addition, soil amendments such as gypsum may also improve the water relations of degraded duplex soils and ameliorate factors inhibiting germination and establishment(2). To determine the best position for seed placement on cultivation and to test the effectiveness of gypsum, a trial was conducted on Woorame1 Station, 120 km south of Carnarvon, in March 1988.


The trial was located on an area of scalded duplex soils which comprised part of an alluvial plain of the Woorame1 River. Seed of spiny bluebush (Maireana aphylla) was placed at various positions on disc pitted cultivation. Five rates of gypsum (0, 1, 2, 4 and 8 t/ha) were added and vermiculite mulch and bitumenous emulsion applied to each placement. Following germinating rains during winter (total of 94 mm), the number of established seedlings were recorded in October.

Results and discussion

Most seedlings established on uncultivated soil adjacent to the margin of the outermost pit (Table 1). No seedlings established on the crest of the central mound. More seedlings established at the waterline postion and halfway up the central mound than in the floor of the pit. The addition of gypsum significantly increased the establishment of spiny bluebush (Table 1). At least eleven times as many seedlings were established in the gypsum treatments. Most seedlings established at the highest gypsum rate.

Table 1. Establishment of spiny bluebush on cultivation, with gypsum amendments, Woorame1 1988 (total number of seedlings at each position)

1. Malcolm, C.V. and Allen, R.J. (1981). Aust. Range, J. 3, 106-109.

2. Malcolm, C.V., Hillman, B.J., Swann, T.C., Denby, C., Carlson, D. and D'Antuono, M. (1982). J. Arid. Envir. 5, 179-180.

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