Introduction: Definition, Evolutionary Trends, Classification, Historical Background, and Prospects of Halophytes in Agriculture

Halophytes have a phenomenal ability to complete their life cycle with optimal growth under saline conditions and represent about 1% of the total flora of flowering plants. During their evolution, various structural and functional adaptive mechanisms have appeared which enabled these plants to tolerate the saline environment. About 1 billion ha of land in the world is salt-affected and about 32,000 km stretches of coastal sands lie unutilised for agriculture. Most of the deserts and arid regions possess saline aquifers. Though there is a long history of using seawater for irrigation in coastal areas, the main attention was paid only after the 1960s when experimentations were initiated on the use of seawater for the irrigation of crops. Now, when the world’s population has crossed the eight-billion mark and is expected to reach nine billion in 2037, the arable land is shrinking fast, and the availability of good-quality water for irrigation is reduced; hence the use of poor-quality water in irrigation is inevitable; the potential of bio-saline agriculture is being recognised globally. During the last two decades or so, the attraction of global researchers and policymakers across the globe has been focused on identifying, evaluating, domesticating, and developing new crops of potential halophytes. Therefore, the present publication has been planned, and introductory information about the halophytes and the publication has been included in this chapter. A brief account of the concept, evolutionary trends, classification, historical background, and potentials of halophytes in agriculture has been given.