This book provides a practical guidance and a set of principles for improving management of saline and alkali waters and thus would be useful for different stakeholders, including agricultural students, researchers, environmentalists, and policy makers. The worldwide aggregated area with occurrence of saline and brackish groundwater is about 24 million square kilometers causing annual food losses to the extent of food requirements of 170 million people. For fostering the safe and reliable use of these waters, researchers have innovated management techniques helping sustainable irrigation with waters otherwise rated earlier as unfit. Vast pool of information has been put together in this book covering groundwater irrigation scenario and need for non-conventional waters; extent, genesis, and global distribution of saline groundwater; impacts of saline and alkali irrigation waters on soils and crops; management approaches for sustaining irrigation with typical saline and alkali ground waters for agricultural and horticulture crops; steady and non-steady state models for salt and water dynamics vis-a-vis crop responses; alternate uses of highly saline waters; water quality guidelines for irrigation under different soil and agro-climatic conditions and ultimately some researchable and policy issues for promoting irrigation with these waters.