Relationship between root cationexchange capacity and sodium tolerance of different crops

Summary Paragrass, wheat, barley, gram, lady's finger, and dhaincha were grown in a soil whose ESP had been adjusted to 1.7, 30.2, 41.4, 58.4, and 77.9. The growth in terms of dry weight of tops and roots decreased with increasing levels of exchangeable sodium percentage (ESP). The sodium-tolerance index was the highest in paragrass (lower-root CEC) followed by barley and wheat (medium root CEC). Dhaincha, gram, and lady's finger (high root CEC) were relatively sensitive crops having low sodium-tolerance index. Fifty per cent reduction in the yield of wheat, barley, paragrass, lady's finger, dhaincha and gram occurred when ESP was 41, 43, 55, 35, 37, and 36, respectively. Increasing ESP of the soil was associated with increasing Na and decreasing Ca, Mg, and K contents of the tops and roots.