Department of Land and Water Conservation
1Gunnedah Research Centre and 2Queanbeyan
Very little is known about the salt tolerance of native grasses. By contrast, a considerable body of information has accumulated over the years about the salt tolerance of crop, exotic grass and legume species. Much of this information came from sampling a wide range of field trials and paddocks, a procedure that depends on time and to some extent on chance.
Two native grasses, plains grass (Stipa aristiglumis) and Queensland bluegrass (Dichanthium sericeum) are very widely distributed and common in northern New South Wales, ** particularly on heavy clay soils that are suspected to contain significant levels of salt. The salt tolerance of both these species, along with a faster, more effective means of assessing the salt tolerance of any plant species were tested in a trial at Gunnedah Research Centre.
The two native grass species, together with two other native grasses for which some information on salt tolerance has been obtained, curly windmill grass (Enteropogon acicularis) and sand couch (Sporobolus virginicus), were grown in pots in a glasshouse at low, moderate and high levels of salinity. The lower levels of salinity were obtained through leaching the known highly saline soil.
All grasses grew well in soil of low salinity, but all died in the highly saline soil. All four grasses grew reasonably well in the moderately salty soil but root growth was severely restricted.
The results suggest that both plains grass and Queensland bluegrass may be quite tolerant of saline soils.