Growth Responses of Alkali Sacaton (Sporobolus airoides Torr.) and Seashore Paspalum (Paspalum Vaginatum Swartz), Two Halophytic Grass Species, to Salinity Stress.

Desertification of the arable lands due to global warming and shortage of water mandates use of saline soils and saline waters for irrigation and cultivation of plant species with high degrees of salt and drought tolerance. Thus, there is an urgent need for finding salt/drought tolerant plant species to survive under such stressful conditions. Our preliminary investigations indicated that alkali sacaton (Sporobolus airoides Torr.) and paspalum (Paspalum Vaginatum Swartz), halophytic grass species, have a great potential to be used under harsh and stressful arid regions’ conditions. Therefore, these grasses were studied in a greenhouse to evaluate their growth responses under control (no-salt) and various levels of NaCl salinity (EC 8, 16, 24, and 32 dSm^-1), using Hoagland solution in a hydroponics system. Four replications of each treatment were used in a complete randomized block design trial. Plant shoots were harvested weekly, oven dried at 70 ^oC, and dry weights recorded. At each harvest, shoot and root lengths were measured and recorded and percentage of visual green cover was estimated. At the last harvest, plant roots were also harvested, oven dried at 70 ^oC, and dry weights were determined. The results showed the low level of salinity (EC 8 dSm^-1) slightly stimulated the paspalum growth. Compared with the control and the low level of salinity (EC 8 dSm^-1), the moderate (EC 16 dSm^-1) salinity level did not have any significant adverse effect on paspalum plants, but the medium (EC 24 dSm^-1) and the high level of salinity (EC 32 dSm^-1) had significant adverse effects on the studied parameters. For the sacaton plants, the low level of salinity (EC 8 dSm^-1) did not have a significant effect on the plant growth, but all other levels of salinity significantly reduced all the studied parameters. Compared to sacaton plants, paspalum was significantly more tolerant to salinity at all the stress levels. These halophytic plant species had a satisfactory growth (paspalum was more tolerant than sacaton) under the low and moderate salinity levels of the experiment higher than the soil salinity levels of the harsh desert conditions. This indicates that these halophytic grasses, can successfully and effectively be used as cover plant species under desert saline soils and prevent dust emission and soil erosion in these regions.