Economic halophytes of Bahrain

Abstract

Early agriculture began more than 10,000 years ago when people planted wild wheat to overcome the shortage in summer food. Since then, agriculture has developed from primitive practice by early man to very advanced and sophisticated industry. Throughout, man was successful in manipulating environmental conditions, including climate and soil, to grow agricultural crops in large scale. However, mismanagement and lack of proper agricultural and ecological practices could cause salt problems and/ or salt accumulation under any climatic system. This is particularly seen in arid lands and poorly draining soils, which are susceptible to salinization. Salinization refers to the surface or near-surface accumulation of salts such as chlorides, sulphates and carbonates of sodium, calcium and magnesium. It also includes alkalization and sodification, which arises from the dissolved salt load of irrigation water (Chhabra, 1996). In many parts of the world the efficiency of many irrigation schemes is low and land degradation problems are widespread. Poorly designed and implemented irrigation schemes can cause water logging, salinization and alkalization of soils (UNEP, 2002). Each year millions of acres of irrigated lands lose their productivity because of salt accumulation. According to FAO (1995a) estimates, 25-30 million ha of the world’s 255 million ha of irrigated land were severely degraded due to accumulation of salts. An additional 80 million ha were reported to be affected by salinization and water logging (FAO, 1995b).

The problem of land salinization and reduction of productivity is not only limited by bad agricultural practice, but the shortage of fresh water is another major obstacle in many parts of the world. In the Arabian Peninsula, the fresh water shortage is a major problem. Water stress in this region is predicted to continue in the next decades as water demands exceed available water resources, owing to population growth and expansion of different development sectors (UNEP, 2002). The future expansion of food production will be increasingly dependent upon sound irrigation and water management and upon the concurrent maintenance of the present agricultural resource base and the environment - two of the most challenging tasks facing mankind today (UNEP, 2002).