Salt Tolerance of Grasses and Legumes for Roadside Use1

Abstract

AbstractSalt injury to grasses and legumes in roadside seedings is becoming an increasingly serious problem in areas where deicing salt is used during winter months. This paper reports on results of three greenhouse trials conducted to evaluate salt tolerance among 40 grass and legume species, cultivars, and genotypes. A 2.65 M sodium chloride (NaCl) solution was added weekly for up to 5 weeks to pots of seedling plants in a Derinda silty clay loam (fine, mixed, mesic Typic Hapludalfs). Salt tolerance was measured by comparing dry matter (DM) yields of salt and no‐salt treatments and by visually scoring foliage injury. In the final trial, which involved a rescreening of the most salt tolerant species from all previous trials, 14 of the 15 entries had salt treatment DM yields which were not significantly different from no‐salt treatment yields, and five also had salt treatment foliage injury scores which were not significantly different from those of the no‐salt treatment. These five were: lemmon alkaligrass [Puccinellia lemmoni (Vasey) Scribn.]; alkali sacaton [Sporobolus airoides (Torr.) Torr.]; nuttall alkaligrass [Puccinellia airoides (Nutt.) Wats. and Coult.]; a Puccinellia roadside selection, and weeping alkaligrass [Puccinellia distans (L.) Parl.]. Entries which had no significant DM yield reduction but showed serious foliage injury were: creeping bentgrass [Agrostis stolonifera L., var. palustris (Huds.) Farw.] cv. Seaside; quackgrass [Agropyron repens (L.) Beauv.]; tall fescue (Festuca arundinacea Schreb.) cv. Alta; perennial ryegrass (Lolium perenne L.) common and cv. NK 200, creeping meadow foxtail (Alopecurus arundinaceus Poir.) cv. Garrison; redtop (Agrostis alba L.); creeping red fescue (Festuca rubra) cv. Ruby; and rough stalk bluegrass (Poa trivialis L.). Among legumes tested, alfalfa (Medicago sativa L.) cv. Vernal and sainfoin (Onobrychis viciaefolia Scop.) cv. Eski were the most salt tolerant, but both ranked lower than the better grasses. Six Kentucky bluegrass (Poa pratensis L.) cultivars were among those entries which had the greatest dry matter yield reductions and the most severe foliage injury when treated with salt.