The Ability Of Distichlis Spicata To Grow Sustainably Within A Saline Discharge Zone While Improving The Soil Chemical And Physical Properties
Landholder observations indicate that the growth of Distichlis spicata in saline discharge sites improves the soil condition. An extensive soil sampling survey was conducted at the Wickepin field site in Western Australia, where D. spicata had been growing for 8 years, to test the hypothesis that this halophytic grass will make improvements in chemical and physical properties of the soil. Soil measurements included saturated hydraulic conductivity, water-stable aggregates, root length and dry weight, electrical conductivity, pH, and soil nitrogen and carbon. Results confirm that marked differences in soil properties occurred under D. spicata. For example, a 12-fold increase in saturated hydraulic conductivity occurred where D. spicata had been growing for 8 years, compared to adjacent control soil where no grass had been growing. There were also improvements in aggregate stability, with the most notable improvements in the top 0.10 m of soil, again with the greatest improvements occurring where 8 years of growth had occurred. Soil nitrogen and carbon increased under the sward, with the biggest increases occurring in the top 0.10 m of soil. Electrical conductivity measurements were more variable, mostly due to the large spatial and temporal variation encountered. However, the findings generally support the proposition that the growth of D. spicata does not lead to an accumulation of salt within the rooting zone.