Effects of irrigation water salinity and leaching fraction on the growth of six halophyte species

Abstract

A pot experiment was carried out at Nahshala Farm, about 50 km from Al-Ain, UAE, during the 1998/99 growing seasons, using six halophytes: Spartina sp., Distichlis palmeri, Paspalum vaginatum, Juncus roemerianus, Salicornia bigelovii and Batis maritima, under two levels of leaching fraction, 0·25 and 0·50 and three levels of irrigation salinity, 10, 20 and 40 g/l. The objectives of the experiment were twofold: (1) to find out the optimum and threshold of saline water irrigation to keep salinity level down as much as possible in the soil using the leaching fraction technique; and (2) to study the response (growth and biomass production) of some halophytes to different levels of salinity. The experiment was conducted in triplicate with a split-plot design arranged in a randomized complete block. Results indicate that these halophyte species can be grown productively at a leaching fraction between 0·25 and 0·50 when salinity of the irrigation water is less than 20 g/l. At higher salinities, Salicornia bigelovii can grow and yield satisfactorily under these conditions, while the other species may require more frequent irrigation at higher leaching fractions. Some of these tested halophytes may be able to revegetate the salt-affected lands and be a potential source of forage in these harsh habitats. This study supports the idea of seawater agriculture by demonstrating the possibility of using some high salt-tolerant halophytes at relatively higher leaching fraction in order to maintain satisfactory yield production of such halophytes.