The effect of selenium on salinity stress and selenate – sulfate comparision in kale

Abstract

Increased salinity is a threat to arid and semiarid zone agriculture worldwide. Kale consumption has increased as its nutritional and antioxidant benefits become more widely known. Compared with other vegetables, it is relatively salt tolerant. However, there is limited information on its salt tolerance, nutrient uptake under saline conditions, and physiological response. We examined the yield response, physiological parameters, and mineral nutrient content of kale grown under variable conditions of salt and Se addition in a greenhouse study. The experiment consisted of four salinity levels, four Se levels, and combined salinity treatments for a total of 16 treatments each with four replications. Salinity decreased yield when irrigated at 6 and 9 dS m−1 but not at 3 dS m−1. Selenium addition increased yield at all salinity levels but did not increase salt tolerance. Addition of 0.25 mg Se per kg of soil, corresponding to leaf Se concentrations of 1 mg kg−1, was sufficient to increase yield by an average of 11% relative to control. Kale yield loss began between 3 and 6 dS m−1 irrigation water salinity and 50% yield loss occurred at EC 6.