Salinity and alkalinity are major abiotic constraints limiting crop productivity, particularly in arid, semi-arid, irrigated and poorly drained environments. Excess soluble salts cause osmotic stress, ionic toxicity and oxidative damage, while sodicity and high soil pH impair soil structure and nutrient availability. Plants mitigate salt stress through osmotic adjustment, ion exclusion, vacuolar compartmentation, antioxidant defence and maintenance of ion homeostasis. However, intrinsic tolerance alone may be insufficient to sustain productivity under field conditions. Agronomic management therefore provides an essential complementary approach through improved drainage, leaching, efficient irrigation, soil amendments, salt-tolerant crops, appropriate planting methods, balanced nutrient management, seed priming and biological interventions. This review summarizes the major impacts of salinity and alkalinity on plants and evaluates key agronomic strategies for improving crop establishment, growth and productivity in salt-affected environments.