Interactive Effects of Hypoxia and Salinity on Perennial Ryegrass and Alkaligrass

A lot of salt-affected soil in the world is also affected by compaction and waterlogging due to shallow water tables or decreased infiltration of water in soil because of sodicity. Waterlogging and compaction cause a reduced oxygen exchange (hypoxia).  Research on the combined impacts of salinity and hypoxia on turfgrass growth is limited.  The interactive effects of salinity and oxygen availability on nine perennial ryegrass lines (Lolium perenne L.) and one alkaligrass (Puccinellia tenuiflora) was studied. In a controlled greenhouse, grasses were exposed to four salinity levels (3, 6, 9, 12 dS·m^–1) with and without hypoxia condition for four weeks each.  All entries exhibited decreased clipping yield with increasing salinity in both salinity and hypoxia + salinity treatments except Fults Alkligrass. Turf quality declined over time to unacceptable quality ratings with high salinity (12 dS·m^–1) treatment.  In general, all entries had better turf quality in control and hypoxia treatments than in salinity and salinity with hypoxia treatments. All grasses were more severely affected (quality and yields) under combined hypoxia and salinity treatment compared to salinity or hypoxia only. The experimental lines that maintained acceptable turf quality under hypoxia plus moderate salinity (6-10 dS·m^–1) conditions were selected.