Abstract: Based on the analysis of the salt content and its composition in farmland soils of Tianjing, this paper studied the characteristics of the salt composition and its accumulation in the salinized farmland soils of the City. Compared with that in non-salinized soils of Jixian County, the salt composition in salinized soils of Dongli, Jinnan, and Hangu districts had obvious difference. In non-salinized soils, salt accumulated in top soil, and decreased with soil depth; while in salinized soils, desalination was obvious in topsoil whereas salt accumulation was observed in subsoil.HCO₃^- was the major anion in both non-salinized and salinized soils, while cations showed a significant difference between non-salinized and salinized soils. Ca²⁺ was the major cation in non-salinized soils, but Na⁺ gradually became the primary cation in salinized soils. The ion composition in salinized soil profiles had a notable spatial variation, e.g., Na⁺, Cl^-, and SO₄^2- had low concentrations in topsoil but high concentrations in subsoil. Moreover, the soil pH value, residual sodium carbonate content, sodium adsorption ratio, and exchangeable sodium percentage in salinized soils were higher, representing the synchro occurrence of salinization and alkalization.

Key words: Cold water irrigation, Multiplication, Rice T(P)GMS line with double low critical temperature values, Critical temperature, Underground water