Response of Daylily (Hemerocallis hybridus cv. ‘Stella de oro’) to saline water irrigation in two coastal saline soils

Abstract

In order to evaluate the effects of irrigation water salinity, applied by drip irrigation, on Daylily (Hemerocallis hybridus cv. ‘Stella de oro’) growth and soil salinity, a three-year experiment was conducted in coastal saline region in Caofeidian District East China during 2013–2015 in two soils (sandy loam and silt). Five water salinity treatments were used with saline water at electrical conductivity (ECiw) of 0.8, 3.1, 4.7, 6.3, and 7.8 dS/m. The original soil salinity expressed as electrical conductivity of the saturation paste extract (ECe) was 27–30dS/m in the 0–95cm depth. Results showed that drip-irrigation was effective in salt leaching. The average values of soil ECe for five treatments were 1–4 and 2–6 dS/m in 0–35cm soil profiles of sandy loam and silt soils, respectively, after 18 months with drip irrigation. In 2014–2015, the survival rates were all >93% when irrigated with saline water at <7.8dS/m for both saline soils. The survival rate and dry mass decreased by 0.63% and 17.14% for each unit of EC increase in the irrigation water in sandy loam saline soil, and the corresponding values were 0.70% and 25.63% in silt saline soil. This study implied that Daylily is a suitable plant in landscape construction of coastal saline soils using drip-irrigation at ECiw<7.8dS/m.