Survival and growth of perennial halophytes on saltland in a Mediterranean environment is affected by depth to watertable in summer as well as subsoil salinity
Document Type
Article
Publication Date
5-29-2013
Journal Title
Crop and Pasture Science
ISSN
Print: 1836-0947 Electronic: 1836-5795
Keywords
drought, land evaluation, salinity, salt tolerance, waterlogging, watertable
Disciplines
Natural Resources and Conservation | Natural Resources Management and Policy
Abstract
Farmers need methods for assessing the capability of saltland for productive use based on characteristics that are readily measurable at the paddock scale. We conducted experiments on saltland transects with gradients of salinity and depth to watertable at three sites in south-western Australia. Each was planted with five perennial species with at least some salt tolerance: samphire (Tecticornia mellaria K.A.Sheph.), river saltbush (Atriplex amnicola Paul G.Wilson), small leaf bluebush (Maireana brevifolia (R.Br.) Paul G.Wilson), saltwater couch (Paspalum vaginatum Sw.), and Rhodes grass (Chloris gayana Kunth). Survival and growth of species was related to depth to watertable in summer and average subsoil (0.25–0.50 m depth) electrical conductivity of the saturation extract (ECe). It has been hypothesised that plant zonation on land affected by dryland salinity is affected by the level of salinity and waterlogging on sites. While plant survival ≥60% could be associated with particular ranges of depth to watertable and soil salinity, our data suggest that the most important factor affecting survival and growth was the presence of shallow groundwater in summer. The range of depths to watertable in summer associated with ‘good survival’ (≥60%) was 0.7–1.0 m with samphire, 0.7–1.6 m with saltwater couch, 0.8–1.5 m with Rhodes grass, 0.7–2.4 m with river saltbush, and 0.9–2.4 m with small leaf bluebush. The subsoil ECe (95% confidence interval) associated with ‘good survival’ was 5–14 dS/m for Rhodes grass, 6–11 dS/m for small leaf bluebush, 7–11 dS/m for river saltbush, 6–16 dS/m for saltwater couch, and 27–65 dS/m for samphire. Growth of the perennial grasses was strongly affected by the presence of a shallow watertable in summer; the size of saltwater couch and Rhodes grass increased many-fold as watertable depths decreased from ~1.3 to 0.9 m from the soil surface.
Recommended Citation
Barrett-Lennard E. G., Bennett Sarita Jane, Altman M. (2013) Survival and growth of perennial halophytes on saltland in a Mediterranean environment is affected by depth to watertable in summer as well as subsoil salinity. Crop and Pasture Science 64, 123-136. https://doi.org/10.1071/CP12416
