Chengchou Han

1 Introduction In recent years, secondary soil salinization has emerged as a particularly serious global environmental problem that can be attributed to both natural factors and human activities, and is considered one of the main environmental risks (Pitman and Läuchli, 2002). At present, it is estimated that globally, approximately 1 billion hectares of land is salinized to various degrees, accounting for approximately 10% of the world’s total arable land.