Response of vegetable crops to salinity and sodicity in relation to ionic balance and ability to absorb microelentents

Abstract

The effect of salinity and sodicity on the growth of and the absorption of metal elements by asparagus, tomato, and bean was investigated. The plants were grown in Tottori sand dune soil with four soil treatments consisting of original soil (exchangeable sodium percentage (ESP) = − 5.8 : Control), saline soil (ESP = 8.8 : Saline), saline-sodic soil (ESP = 16.2 : Sodic 1), and sodic soil (ESP = 40.8 : Sodic 2). Shoot dry weight (DW) of the three species was smaller with increasing ESP. Growth of asparagus and tomato was suppressed in the Saline soil and strongly suppressed in both Sodic soils. Bean could not survive under Saline and Sodic conditions. The Na concentration in the shoots of the three species was higher with higher ESP. The suppressed growth of asparagus in the Sodic soils was partly due to high concentration ratios of Na to essential cations in the shoots. The imbalance between Na and essential cations in the shoots in the Sodic soils which was more pronounced in tomato at the first harvest, improved afterwards. Asparagus and tomato showed a lower ability to absorb low-available microelements in both Sodic soils than in the Saline soil, except for Fe in asparagus. Higher ability of bean to absorb microelements compared with asparagus and tomato, except for Mn, could not improve growth, due to the inadequate ionic balance in the shoots. We conclude that ionic balance in the shoots and the ability to absorb low-available microelements control the tolerance to salinity and sodicity of vegetable crops as in the case of grain crops.