Urban soil salinity presents a major economic threat to residents, city councils and tourism in affected areas. Current research aims to improve the effective selection and management of salt-tolerant grasses, which function in a range of roles and conditions to alleviate the negative implications of urban salinity.
|Full title||Establishment and management of salt-tolerant amenity grasses to reduce urban salinity effect|
|Dates||Start date: February 2009
End date: May 2010
|Project leader||Dr Rachel Poulter, 07 3824 9514
|Benefits||This work will provide tools for those responsible for the management of turf grass on salt-affected land. As the issue of soil salinity increases in importance and the use of saline irrigation water escalates, the findings of this study will serve to protect the economic, social and cultural value of saline amenity areas.|
This project built on the successful outcomes of project TU02005 by adding to the database of salt tolerance among warm season turf grass cultivars, through further hydroponic screening trials. Hydroponic screening trials focussed on new cultivars or cultivars that were not possible to cover in the time available under the previous project, including: 11 new cultivars of Paspalum vaginatum; 13 cultivars of Cynodon dactylon; 6 cultivars of Stenotaphrum secundatum; 1 accession of Cynodon transvaalensis; 12 Cynodon dactylon x transvaalensis hybrids; 2 cultivars of Sporobolus virginicus; 5 cultivars of Zoysia japonica; 1 cultivar of Z. macrantha, 1 common form of Z. tenuifolia and 1 Z. japonica x tenuifolia hybrid.
The relative salinity tolerance of different turf grasses is quantified in terms of their growth response to increasing levels of salinity, often defined by the salt level that equates to a 50% reduction in shoot yield, or alternatively the threshold salinity.
The most salt tolerant species in these trials were Sporobolus virginicus and Paspalum vaginatum, consistent with earlier findings (TU02005: Loch, Poulter et al. 2006). Cynodon dactylon showed the largest range in threshold values with some cultivars highly sensitive to salt, while others were tolerant to levels approaching that of the more halophytic grasses. Coupled with the observational and anecdotal evidence of high drought tolerance, this species and other intermediately tolerant species provide options for site specific situations in which soil salinity is coupled with additional challenges such as shade and high traffic conditions.
Results of earlier turfgrass salinity trials (Project TU02005)