(=) The types of soil acidity 1. Active acidi Active Acidity -The activity of hydrogen ion in the aqueous phase of a soil expressed as a ph value. 土壤减的级 等级 pH值 超强砖 极强度 35~44 强性 4.5~4 张性 55-64 甲性 6s-7 7b~85 强碱性 86-95 极强碱注（二）The types of soil acidity 1．Active acidity Active Acidity –The activity of hydrogen ion in the aqueous phase of a soil expressed as a pH value