Research Progress on Saline Soil Improvement: Mechanisms, Influencing Factors, and Technologies

Abstract As a widely distributed type of degraded land, saline soils form and evolve through interactions among natural factors and human activities. Saline soil improvement technology has emerged as a core tool for land degradation management due to its multidimensional benefits, including increased agricultural yield, engineering stabilization, and ecological restoration. This paper systematically summarizes four types of improvement technologies (physical solidification, chemical improvement, bioremediation, and synergistic improvement) and the progress of their application in saline soil management. It comprehensively analyzes the mechanisms of improvement (salt washing, ion exchange, and microbial action) and the key influencing factors (soil type, climatic conditions, and amendment compounding). Additionally, the environmental risks (chemical residues from improvements, risk of biological invasion) associated with the implementation of the technology are highlighted. It has been found that physical solidification is suitable for rapid salt reduction in coastal saline soil, whereas chemical improvement is effective for inland sulfate saline soil. Bioremediation can achieve long-term stabilization of saline soil in arid regions, and synergistic improvement technologies (physical–chemical–biological combinations) demonstrate comprehensive advantages for composite saline soil. However, the large-scale application of existing technologies is still constrained by challenges such as long-term effectiveness verification, analysis of multifactor coupling mechanisms, and management of high-salt, heavy-metal composite pollution. This paper aims to provide theoretical support for the precise application and sustainable development of saline soil improvement technologies.