Physical and Chemical Characteristics of Salt-Affected Soils in India

Understanding on physical and chemical properties of salt-affected soils (SAS) is imperative for planning and executing reclamation programs and greening degraded salty lands for agricultural use. This issue received priority in Indian agriculture since pre-independent period and still occupies the central agenda in current policies of agriculture and the welfare of the farming community. Largely, SAS is categorized into saline due to soluble electrolyte load; sodic as it contains disproportionately large amount of sodium upon calcium and magnesium in the soil exchange sites and the soil solution with alkaline reaction; and saline–sodic with the dual problem of alkaline pH and salinity and typical categories of SAS having spatial existence. SAS often coexists with poor quality (saline, sodic, or both and associated problem) groundwater, prolonged water trajectories, erratic rainfall, and high evapotranspiration demand for crops under arid to semiarid agroecology. The physical and chemical properties of SAS demand specific reclamation strategies or management of soils to grow the crop. Further, application of mineral or organic amendment, soil types, and irrigation with varied quality water concomitantly change the chemical equilibria and may degrade soil physical health. Inherently, SAS is disturbed with the ionic environment that had impact on the different processes of nutrient cycles operating in these soils. Therefore, guidance on soil physical and chemical environment, distribution of SAS in India with their physiochemical characteristics in different agroecoregions, and the impact of saline–sodic water on SAS are highlighted.