Growing in dry, saline and nutrient deficient conditions
Atriplex nummularia, or Oldman Saltbush (OMSB) is a drought and salt tolerant shrub that is native to arid areas of Australia. Alongside other native shrubs it is adapted to dry, saline and nutrient deficient conditions and can often be planted in agricultural systems where traditional cereal crops cannot.
OMSB was identified for its ability to not only provide supplementary forage to fill annual feed gaps in livestock production but for its potential to use and regenerate land that is too saline, infertile or depleted for conventional crops and forages. It is also associated with environmental benefits such as preventing water recharge and mitigating dryland salinity and increasing biodiversity.
Unfortunately, OMSB’s ability to grow in dry, saline and nutrient deficient conditions is associated with high levels of salt and oxalates accumulation in its leaves, leaving it less palatable and decreasing nutritional value. Voluntary feed intake and digestibility (energy value) are primary drivers of on-farm profitability. Unfortunately, the majority of OMSB plants across Australia have digestibility that is sub-maintenance for mature sheep or cattle. Achieving on-farm economic benefits requires livestock to choose to voluntarily consume a suitable diet. Hence, a need to improve its digestibility and relative palpability was identified as the key selection traits if OMSB was to be adopted as a widespread productive feed-gap delivering economic and environmental benefits across the Australian landscape.
CSIRO, alongside research partners in a multi-organisational R&D collaboration sought to improve OMSB suitability as a fodder supplement and began a saltbush research improvement program in mid 2000’s. The program included clonal selection from a collection of wild germplasm leading to the selection and release of the elite variety, Anameka™ in 2015. Anameka™ was chosen on the basis of higher energy value and eight times more biomass than other saltbushes in the collection. It’s nutritional profile and improved relative palatability increases voluntary livestock intake, provides higher energy values and increases livestock productivity.
CSIRO’s contribution to this process was the application of deep multi-disciplinary understanding of farming systems, animal nutrition and plant science. Since 2015, CSIRO has led the program of work by carrying over the tender of Anameka™ and leading ongoing OMSB improvement research.
Improved farm profitability and productivity
Since 2014, over 287 producers have purchased and planted more than 2.4 million Anameka™ shrubs, equivalent to 3728 hectares at a recommended rate of 650 plants/ha.
We estimate that the net present value of the R&D investment into Anameka™ is approximately $12.3 million (or 3.4:1) in 2020/21 dollars at 7 per cent discount rate given model assumptions.
The impacts of Anameka include:
- Improved farm profitability due to a perennial forage shrub with higher feeding value and relatively palatability (e.g. greater livestock carrying capacity, increase in wool production and strength and/or improved animal health).
- Reduced farm seasonal risk exposure and risk in decision making particularly in poorer years due to filling the feed gap and improved drought resilience and/or ecosystem services
- Potential improvement in retailer profitability due to increased shelf life (meat stays redder for 2-3 days longer) due to greater Vitamin E and other anti-oxidants
- Ecosystem services including
- Improved landscape functioning through reduced risk of dryland salinity. Risk of salinity reduced due to reduction in water table preventing future recharge.
- Habitat for beneficial insects, native birds and lizards
- Greater plant diversity and re-colonisation of native species in revegetated paddocks
- Potentially more resilient rural communities due to improved financial resilience of mixed farm and grazing operations
- Improvement to visual amenity due to reduced bare salt land and degraded land