灌漑・排水システム工学

Irrigation Water Salinity Effects On Germination and Emergence of Six Halophytes

Abstract

Omer Faruk Ozturk, Manoj K Shukla , Blair Stringam and Charlotte Gard

Low availability of surface water has exacerbated the use of groundwater for irrigation in New Mexico. About 75% of the groundwater in NM is brackish and prolonged application without treatment could increase soil salinity. Reverse Osmosis (RO) treats brackish groundwater but disposal or reuse of RO concentrate is a problem. The objective of this study was to test germination and emergence of six halophyte species under a water salinity gradient. Four irrigation water treatments were tap water (EC 0.8 dS/m), brackish groundwater (EC 5.0 dS/m), RO1 concentrate water (EC 8.0 dS/m), and RO1 concentrate mixed with NaCl (RO2; EC 10 dS/m). Experiments with six halophytes species (Atriplex canescens, Hordeum vulgare, Lepidium alyssoides, Distichlis stricta, Panicum virgatum, xTriticosecale) were carried out for 30 days in a greenhouse. H. vulgare and xTriticosecale had no significant difference in percent germination with higher germinations under salinity treatments, and other species showed similar germinations under higher salinity treatments. On the other hand, D. stricta seeds displayed lower germinations under higher salinity treatments. Results of the emergence percentage showed that H. vulgare and xTriticosecale had no significant difference with higher emergence under higher salinity treatments, while other species showed similar emergence percentage under higher salinity treatments. In contrast, L. alyssoides and A. canescens seeds showed lower emergence percentage under higher salinity treatments. Increasing irrigation water salinity increased mean germination time for all species except L. alyssoides, but did not affect the percentage germination significantly except for A. canescens. Increasing irrigation water salinity increased mean emergence time for all species except L. alyssoides, but did not affect the percent emergence for H. Vulgare, xTriticosecale, and P. virtagum species significantly. Results showed that H. vulgare (barley), xTriticosecale (triticale), and P. virtagum (switchgrass) are candidate species for irrigation with brackish groundwater and RO1 concentrate in water scarce areas. However, their survival and growth should be further tested in different soils.