Producing biomass: Biomass types: Crops: Native grasses
Australia has about 1000 species of native grasses which can be converted to liquid fuel, or combusted to create electricity.

Benefits of growing native grasses for bioenergy

Native grasses can be converted to liquid fuel, or combusted to create electricity.

They offer major opportunities as energy crops, because of their highly developed production technologies:
  • Cultivation is highly developed because grasses include cereals, pasture and turf species.
  • Machinery for planting and harvesting of grain, forage and lawns is very advanced.
Other countries have developed biofuel production systems based entirely upon selections made from their native grass species.

Australia has around 10% of the grass species in the world, despite occupying only 5% of the world’s land surface area. Many of these species are very long-lived and hardy, and produce significant biomass quantities.
Kangaroo grass (Themeda triandra) Credit: Native Seeds Pty Ltd
Grasses have many advantages as a source of biomass:
  • They can produce biomass cheaply.
  • They produce biomass every year.
  • They are easy to manage.
  • Harvesting equipment is commonly available.
  • They can supply biomass in their first year.
  • They can serve more than one purpose such as grain or grazing.
  • They are much easier to convert to fuel than biomasses such as timber.
  • Native species are far less likely to become weedy than introduced species.
  • Australian native grasses are generally adapted to poor, leached soils and are able to survive harsh climatic conditions.


Perennial grasses offer advantages over annual grasses:
  • They are more ecologically sound (less potential for soil erosion).
  • They store more soil carbon.
  • They are cheaper and less risky to grow.


The report, Evaluation of biomass potential of some Australian native grasses, published in 2011 by RIRDC, evaluates the potential of 5 Australian native grass species to be grown as energy crops:
  • Kangaroo grass (Themeda triandra)
  • Tall Oat grass (Themeda avenacea)
  • Wild sorghum (Sorghum leiocladum)
  • Large Tussock grass (Poa labillardieri)
  • Black Spear grass (Heteropogon contortus).
The research sought to determine whether these species are capable of producing enough biomass at a price that would be competitive with renewable sources such as timber and algae.

The results showed wide variation in biomass potential of the 5 species. Some species offer potential as biofuel crops and deserve to be evaluated thoroughly.

Evaluating the economics

Native and introduced grasses could be grown and harvested using existing equipment, labour and capital on most farms in southern Australia (see Chapter 11, Section 11.3 of Bioenergy in Australia: Status and opportunities, published by Bioenergy Australia in 2012).

The report presents the production economics of a hypothetical grass crop grown in the south-west agricultural region in Western Australia. This region has an annual rainfall range of 450–600 millimetres.

Growing native grasses

Grassed up – guidelines for revegetating with Australian native grasses is published by NSW DPI. The guidelines are intended for revegetation/rehabilitation or for seed production, but they offer practical information about sowing, establishing, managing, harvesting, and storing seeds.

The Department of Agriculture in Western Australia offers fact sheets on native pastures in WA, for a number of species.

The NSW DPI offer information on native grasses, managing and sowing native grasses, and on the species suited to tablelands, slopes and plains.

Native Seeds Pty Ltd sells seeds and has information on soil, tolerances and sowing.

Native Grass Resources Group Inc. in South Australia has a database of grass seed suppliers and growers.

Stipa Native Grasses Association, based in Victoria, has information about identifying native grasses.
Tall oat grass (Themeda avenacea)Credit: Native Seeds Pty Ltd

Harvesting native grasses

Harvesting native grasses, a paper by Andrew Briggs, NSW, offers practical information about harvesting native grass seed, but some of the information may also be relevant to harvesting the grass as a feedstock for bioenergy.

Supplying native grasses

Production and transport costs are provided in Chapter 11 (Sections 11.3 and 11.4) of Bioenergy in Australia: Status and opportunities, published by Bioenergy Australia in 2012.

Contacts

Prof. Robert Henry

Queensland Alliance for Agriculture & Food Innovation (QAAFI)

The University of Queensland, St Lucia, QLD 4072
Phone: 07 3346 0551

robert.henry@uq.edu.au
Dr Ian Chivers

Native Seeds Pty Ltd

34/148 Chesterville Road, Cheltenham Vic 3192
Phone: 03 9555 1722

ian@nativeseeds.com.au