Phytoremediation of brine-affected soil with salt-tolerant plants: a screening study

Abstract

Phytoremediation is an attractive alternative to traditional soil remediation for brine-affected areas. Potential phytoremediation plants must possess several key characteristics including adaptation to semi-arid climate, moderate to high salt tolerance, accumulation of Na in above ground tissues and an extensive root system to obtain Na and improve soil structure. Eighteen salt-tolerant species were identified from literature and screened for sodium uptake ability in a sand culture experiment. Plants were treated with 0, 200, 400 and 600 mM NaCl and grown for 50 d. Plants were harvested and biomass analyzed for Na content. Sea blite (Suaeda calceoliformis) and salt grass (Distichlis stricta) showed promise for phytoremediation by surviving high levels of Na while developing extensive root systems. These species did not accumulate as much Na in their aboveground tissue as less tolerant plants. However, during this short screening study, cell wall integrity was maintained and a longer study would allow plants to accumulate more biomass and Na. These two species will be tested on contaminated saline sodic field soil to provide an understanding of sodium removal over the length of a Saskatchewan growing season.