Saline irrigation of five diverse landscape species for the southeastern United States.

摘要

Greywater is a recycled water source that can help reduce the demand for potable water. Use of greywater for irrigation is limited by a primary contaminant, sodium chloride (NaCl). Research was conducted to evaluate five landscape species for tolerance of saline irrigation. Species used were Illicium parviflorum, Itea virginica 'Henry's Garnet,' Muhlenbergia capillaris, Portulaca oleracea. 'Big Bloom Red' and Begonia Semperflorens Cultorum Group CocktailReg., WhiskyReg. wax leaf begonia. Plants were irrigated with tap water containing one of the following concentrations of NaCl: 0, 2000, 4000, 6000, 8000, or 10000 mg.L-1. Portulaca oleracea and Begonia Semperflorens Cultorum Group were harvested after 6 weeks. Three replications from the remaining species were harvested after 5 and 10 weeks, and the final four replications were harvested after 15 weeks. Root dry weight (RDW) and shoot dry weight (SDW) were determined at each harvest; survival was determined at experiment termination. Root dry weight and SDW of I. parviflorum, I. virginica, P. oleracea, and Begonia decreased linearly with increasing NaCl conc, at each harvest. RDW of M. capillaris decreased with increasing NaCl conc 10 and 15 weeks after treatment initiation however; there was no effect of NaCl concentration on SDW of M. capillaris 10 and 15 weeks after treatment initiation. I. virginica exhibited foliar damage at the lowest NaCl conc. Plant mortality occurred for I. virginica which had 0% survival in 8000 and 10000 ppm (mg.L-1) NaCl treatments at 15 weeks, while Begonia Semperflorens Cultorum Group had foliar damage at 6000 ppm (mg.L-1) and mortality at 6000 ppm (mg.L-1) (90% mortality) and 10000 ppm (mg.L-1) (50% mortality). All species evaluated, except I. virginica, were tolerant of saline irrigation that could be expected from greywater.