Salinity stress is one of the main constraints that adversely affect crop yield and quality. About one-fifth of irrigated agricultural land is adversely affected by salinity (Chinnusamy et al., 2005). The problem of soil salinity is increasing because of the use of poor quality water for irrigation and poor drainage (Chinnusamy et al.,
2005). Given the amount by which food production will have to be increased due to the growth of human population, it is desirable to increase the tolerance of crops to salinity stress. Plant nutritionists are trying to increase the tolerance to stress (including salinity) through the use of chemical additions to the soil.