干旱区生态环境知识资源中心

Conversion of agricultural lands and continuous desertification processes due to urban development and global warming causes increasing evapotranspiration rates resulting in more water deficit and drought stress conditions. This phenomenon mandates use of low quality waters for irrigation, especially in regions experiencing water shortage. Using low quality water for irrigation imposes more stress on plants which are already under stress in these regions. Thus, a reasonable remedy could be finding drought tolerant plant species to survive/sustain under such stressful water deficit conditions. Since the native plants are already growing under such conditions and are adapted to these stresses, they are the most suitable candidates fir use under these harsh arid conditions. If drought tolerant species/genotypes of these native plants are identified, there would be a substantial success in re-vegetation of the arid regions by using these plant species under these stressful conditions. Our studies on various native grasses indicated that saltgrass, a drought tolerant species with very low water requirements, has a great potential to be used under harsh environmental desert conditions and combat desertification. The objectives of this study were to find the most drought tolerant types of various saltgrass clones and to recommend them as the potential species for use under arid regions and areas with limited water supplies or drought conditions for sustainable agriculture and combating desertification. Various saltgrass clones were studied in a greenhouse to evaluate their growth responses under prolonged drought stress at different mowing heights. Grasses were grown vegetatively in galvanized cans contained fritted clay. The growth responses of the grasses were evaluated under progressive drought condition for 4 months in a split plot design experiment with 3 replications at two mowing heights. Shoots were harvested bi-weekly for DM determination and grass quality was weekly evaluated. Although growth responses reduced as drought period progressed, all the grasses showed a high degree of drought tolerance. However, there was a wide range of variations observed in drought tolerance among the clones at each mowing height. At the termination of the drought period, some clones did not survive, while some showed about 20% green canopy. Compared with the 5 cm mowing height, the 2.5 cm mowing height grasses maintained their canopy green color for longer time. The superior drought tolerant clones were identified which could be recommended as the potential turfgrass species for use under regions with limited water supplies or drought conditions as well as for sustainable production under arid regions and combating desertification processes.