Salinity affects root growth of container grown saltgrass

Abstract The need for salinity tolerant turfgrasses is increasing because of the growing use of effluent or other low‐quality waters for turfgrass irrigation. Salinity can affect soils and plants in all climates but is particularly common in arid environments and has numerous causes. Salinity impacts the growth of most plants, albeit with variations among species. The objective of this experiment was to quantify the effects of salinity on root growth of an experimental line of saltgrass ( Distichlis spicata L. Greene) (SG) and NuGlade Kentucky bluegrass ( Poa pratensis L.) (KBG), two grasses with contrasting salinity tolerance. In this experiment, SG and KBG were grown in containers within separate growth chambers, each maintained at their optimal growing temperatures. Salinity was imposed on the plants by irrigating with saline waters of ∼0, 8, and 16 dS/m for SG and ∼0, 4, and 8 dS/m for KBG. Root growth was monitored using minirhizotron and in‐growth root cores. The data from in‐growth root cores revealed contrasting effects of salinity on root and rhizome growth trends between SG and KBG. Root growth of SG increased by 22% under 8 and 16 dS/m salinity treatments. Conversely, salinity treatment of 8 dS/m decreased KBG root growth by 33% compared to the control. Saltgrass rhizome growth increased by 130% with the rise in salinity from the control to 16 dS/m treatment, whereas KBG rhizome growth decreased by 57% as salinity increased from the control to 8 dS/m. Minirhizotron observation indicated that SG showed increased flushes of fine roots in the moderate levels of salinity (8 dS/m) compared to the control about 3 weeks after salt treatments began. Increased fine root production greatly increased the root surface area for absorption, an adaptive response of SG to salinity. Turf quality did not deteriorate by even the highest level of salinity tested in saltgrass, suggesting it is a good candidate for turf growing under saline conditions.