The native old-man saltbush (OMSB), Atriplex nummularia, is a deep-rooted perennial shrub that is tolerant of drought, saline soils and shallow water tables. This plant can be used to lower water tables and stabilise soil. It is excellent in helping to reduce salinity impact in vulnerable areas as its deep rooting ability will ensure that recharge is reduced. It can also assist in reclaiming saline land.
OMSB can reduce soil erosion by binding the topsoil and reducing wind which will also protect other plants and animals. Saltbush will also act as a fire retardant.
OMSB plantations can be used to relieve pressure on other paddocks at critical times allowing establishment and regeneration of desirable perennial species.
As a fodder plant OMSB provides insurance against droughts as well as increasing farm productivity. OMSB is palatable to livestock and can provide succulent high protein green feed year round. It is an ideal supplement to good quality pasture, stubble or grain. Also, as leaves are off the ground, there is no loss through trampling and there is a reduced incidence of internal parasites in stock.
Once established, OSMB will remain productive for at least 20 years providing the basis for a sustainable, highly productive and consistent grazing system. Its capacity to retain leaf under dry conditions allows the period of green feed availability to be extended. When OMSB is used in conjunction with other pastures it allows landholders to change to more profitable land use practices (e.g. from wool to prime lamb production).
There is a one-off cost for establishing OMSB with minimal ongoing costs. The economic benefit of this system will vary with annual price fluctuations. However, significantly improved returns can be obtained from grazing sheep & cattle on OMSB over a 10 year period compared to dryland cropping or grazing animals on annual pastures. This does not include the added benefits from land management flexibility, reduced business risk, shelter and strengthened sustainability.
Climate and soil suitability
Saltbush is suited to most of the main 'wheat-belt' areas of the lower slopes and plains of NSW (see Map). It is well adapted to areas with an annual rainfall of between 250 and 600 mm. Saltbush prefers alkaline soils but is suited to most soil types except very acid (pHCaCl <5.0) or deep sandy soils and areas subject to frequent summer flooding.
One additional key consideration to be taken into account is the Aluminium level in your soil - levels above 2% cec (cation exchange) are unsuited for Oldman Saltbush planting
The map shows suitable regions accross Australia, but the shaded areas do not guarentee Oldman Saltbush can be grown there. The factors above also need to be taken into account.
An OMSB plantation is a permanent planting and requires careful planning, capital input and time. The shrubs can be grown in a range of configurations including hedge-rows, high or low density blocks or alley plantings across the landscape - to provide shelter for both animals, pasture and soil.
For best grazing performance, OMSB needs inter-row or adjacent pasture areas to supply an energy source for animals. Perennial pastures are suited as a companion sward and can be established either prior, during or after saltbush planting.
Saltbush is best used to fill seasonal feed gaps and to provide a high protein supplement to other dry pasture and stubble. Strategic de-stocking of perennial grass country after rains is also a most important use. With these management uses in mind, the planning of plantation block sizes should relate to total stock numbers and the duration that OMSB is intended to be grazed for.
Transplanted seedlings should be used to successfully establish plantations. Direct seeding is optional but not recommended for most areas of NSW as results have been very variable.
Prepare the land well in advance, work to a depth of 15 to 20 cm and keep it clean of any weeds. OMSB should only be planted when adequate sub-soil moisture is available. Avoid planting seedlings during mid-summer. Seedlings should be 'watered-in' at planting.
Plant densities should be between 1000 and 2500 plants per ha. Seedlings planted at the higher density are usually planted in skip rows of 2 & 4 m rows with 1.2 m intra-row spacings. Plantings should be on the contour on sloping land.
OMSB is a very poor competitor with other pasture species and good early weed control is critical for successful establishment.
Once established, OMSB is best managed by short periods of heavy stocking followed by a long spell to allow plants to re-grow and strengthen root reserves. Saltbush is not a living haystack; it needs to be well managed to remain a productive feed source.
Do not graze new saltbush stands for 10 to 12 months. Grazing should be no longer than 2 to 3 weeks for any one sub-division, then followed by an 8-10 month recovery period. Sub-divisional fencing of a plantation should ensure that grazing of all plants can be achieved in this time. Stock should be removed after total defoliation of leaf. Plants may need a periodic mechanical pruning to lower branch height to keep leaf within 'bite-height' of animals.
Young stock need to be educated to eat saltbush, similar to that for grain and other new feed sources. This may take three or four weeks. The inclusion of some older experienced stock helps to hasten this process.
Even mature stock can at times take several weeks to acclimatise each time they are introduced to OMSB. Therefore, extended periods of grazing give better results than one-off short-term grazings. This is best achieved by rotating stock through several small paddocks planted to OMSB.
The best use of the feed and shelter, for young animals, can be achieved by initially grazing lambs or lambing ewes in a fresh block, followed by a flock of wethers to clean up the remainder.