ABSTRACT
Salinity is the major limiting factor in crop production in irrigated agriculture and constitutes the most serious water-quality threat in many rivers and groundwater systems located in arid and semiarid regions. The problem of salinity in agriculture is not new. Historically, societies that judiciously managed their soil and water resources survived. Other less prudent societies succeeded temporarily, but failed eventually. The rise of the Mesopotamian civilizations of the Fertile Crescent has been attributed to the development of irrigated agriculture and their subsequent decline to rising water tables and soil salinization. The ancient Sumerian farmers attempted to cope with salinization by fallowing their land and replacing relatively salt-sensitive wheat with barley, a more salt-tolerant crop. Their efforts failed and the great cities of the Tigris-Euphrates valleys disappeared only to
47.1 Introduction .........................................................................................................................1173 47.2Plant Response to Salinity ...................................................................................................1174
