ABSTRACT
It is forecasted that by 2050 the world population will increase from the current level of approximately 6 million people to more than 8 billion. Feeding this population will require an increase in food production, especially in developing countries. For the foreseeable future, conventional agriculture will be our primary response, with cereal grains playing a pivotal role (Hoisington et al., 1999). In contrast to the enormous gains in plant productivity, the extension of irrigated agriculture, poor local irrigation practices, and the intensive use of water resources, combined with high evaporative rates in arid and semiarid regions, have inevitably given rise to the problem of salinity in the soil and in underground water (Koyro and Huchzermeyer, 2002b). Every year, 6 million ha of arable land are lost in developing countries and the economic existence of more than 1 billion people in 100 countries is threatened by the expansion of the deserts.
