碱化盐渍土多在我国干旱和半干旱地区,与其它类型盐溃土插花分布。这类土在北京地区约占盐碱地总面积的三分之一,近年来还有扩大的趋势。一、性状(一)盐碱特性。此类土壤的共同特点是盐分组成的阴离子中碳酸根离子(CO_3~-)和碳酸氢根离子(HCO_3~-)所占的比例高,一般可达35%。阳离子组成的特点是 Alkaline saline soil mostly in arid and semi-arid areas of China, and other types of salt-prone soil scattered flower arrangement. Such soil in Beijing accounts for about one-third of the total area of ​​saline-alkali land, and in recent years there is an expanding trend. First, traits (a) saline-alkali characteristics. The common feature of these soils is that the proportion of carbonate ions (CO 3 -) and bicarbonate ions (HCO 3 -) in the anions formed by the salts is high, generally up to 35%. Cationic composition is characterized by