Soil Science: Fundamentals to Recent Advances | 2021
Saline and Sodic Ecosystems in the Changing World
Abstract
Soluble and precipitated electrolytes are the primary cause for developing salinity and sodicity of soil and consequently impede ecosystem functions and limit crop performance. Reclamation of salt-affected soil is a central agenda in current policies of India and salt-affected countries to meet the food-feed-fibre and bioenergy demand of a rising population. Worldwide expansion of irrigated farming in canal commands, sea level rise, shortage of freshwater, coastal land subsidence, erratic behaviour of rainfall, rising in temperature, occurrence of drought demand more evapotranspiration requirement of the plants and consequently import salt-load in the root zone under saline water irrigation or canal commands with improper drainage promote risk of salinization, sodication, high SAR (sodium adsorption ratio), deterioration of soil physical condition, presence of large quality of Mg than Ca, and development of alkalinity in soil. Severely salt affected soil remains near to barren and support very limited plant growth. The low biomass yield and reduced rhizodeposition and crop residue return to soils results in low build-up and storage of soil organic C (SOC) and imbalance in essential nutrients for survival of plant and organism in these ecosystem. Here, we have tried to recount the concept and classification of saline ecosystem, its global extent, and impact of changing climate on salinity and associated stress, effect of poor quality water on salinity development, changes in SOC and nutrients in saline ecosystem. Further, several agro-technological options to mitigating the adverse effect of salinity and need of amendment for rehabilitation of sodic soils are described to combat salinity and sustain crop production.