Effect of combined water and salinity stress factors on evapotranspiration of Sedum kamtschaticum Fischer in relation to green roof irrigation

• Published in: Urban forestry & urban greening 2013, Vol.12 (3), p.338-343
• Main Authors: Moritani, Shigeoki, Yamamoto, Tahei, Andry, Henintsoa, Inoue, Mitsuhiro, Kato, Koh, Saito, Hirotaka
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; arid lands; Biological and medical sciences; biomass; Computer aided manufacturing; Crassulacean acid metabolism; electrical conductivity; equations; evapotranspiration; Forestry; Fundamental and applied biological sciences. Psychology; General aspects; green roofs; Intermittent saline irrigation; Irrigation; irrigation scheduling; irrigation water; Irrigation. Drainage; Moisture content; municipal wastewater; Plants (organisms); Power plants; saline water; Salinity; salt stress; Sedum; Sedum kamtschaticum; Soil (material); Soil tillage. Irrigation. Drainage; soil water; soil water content; Soil water potential; solutes; Stress factor; Stresses; water salinity; Water-use efficiency
• ISSN: 1618-8667; 1610-8167
• DOI: 10.1016/j.ufug.2013.04.005

In dryland areas, secondarily treated municipal wastewater could be used in extensive green roof systems. In this study, the effects of water and salt stress on a crassulacean acid metabolism (CAM) plant, Sedum kamtschaticum Fischer, was evaluated under intermittent saline irrigation. The salinity of irrigation water varied from 6.0 to 18.0dSm−1. A reduction in soil water content and an increase in soil water electrical conductivity (EC) were observed during the irrigation interval (5–17d) as a result of evapotranspiration (ET). The effect of soil water potential (SWP) on reduction of the ET ratio (ETr) was successfully described with an equation that could be applicable to a wide range of soil salinities and water contents, to estimate ET. In this study, the stress factor was defined as the integration of solute potential, and matric potential less soil water content for optimum growth (less than −0.1MPa) with elapsed time. The stress factor rapidly reduced total ET in CAM plants but effectively increased water-use efficiency (WUE). Thus, by using CAM plants for green roofs under intermittent saline irrigation, the need for irrigation water is reduced without a considerable loss of plant biomass.