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Atriplex nummularia
(Old man saltbush)
Life
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Archaeoplastida >
Chloroplastida
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Charophyta > Streptophytina > Plantae (land plants)
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> Core Eudicots
> Order: Caryophyllales > Family:
Amaranthaceae > Subfamily:
Chenopodioideae > Genus: Atriplex
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| Atriplex nummularia
(Old man saltbush), karoo near Laingsburg. [photo H. Robertson, Iziko
©] |
Close-up of leaves of Atriplex nummularia.
[photo H. Robertson, Iziko ©] |
Atriplex nummularia is native to Australia
and has been introduced to arid and semi-arid areas of the world, including
southern Africa, where it has become naturalised and is also grown as a fodder
plant. It is a declared
Category 2 invasive plant in South Africa, which means that it can only
be cultivated in certain demarcated areas with permission. It grows as a bush,
reaching 2 m in height and 2.4 m wide.
Uses
Old man saltbush has a number of properties which make it
useful for fodder in dry, inhospitable areas:
- It can grow in regions experiencing only 150-200 mm annually and can
survive a drought year of 50 mm of rainfall.
- It is frost-resistant, being able to survive temperature as low as
-10șC.
- It is a halophyte, being able to grow in soils with high salinity
levels.
- The leaves have high nitrogen levels and sheep fed this plant in
combination with hay increase in weight. However, sheep do not prosper on
Old man saltbush as a sole fodder plant and under these conditions their
weight, at best, remains the same. There are high levels of sodium in the
leaves, requiring that sheep increase their water intake from 3.2 kg/day on
grasslands to 7-7.5 kg/day on Old man saltbush. The recommendation is to
limit consumption of Old man saltbush to about 25-30% of the diet.
Cultivation
One slight limitation is that Old man saltbush requires
fairly deep soils for propagation so it is usually grown along floodplains. It
can be easily propagated from stem cuttings with greatest success achieved in
spring using new growth cuttings.
References
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Aganga, A.A., Mthetho, J.K. and Tshwenyane, S.
2003. Atriplex nummularia (Old man saltbush): a potential forage crop
for arid regions of Botswana. Pakistan Journal of Nutrition 2(2): 72-75.
Text by Hamish Robertson |
