PAM was mixed with the soils (sodic and nonsodic soils), respectiviely, or spread over surface of the soils at a rate of 0, 1/5 000, 1/2 000, and 1/1 000 (PAM/dry soil in weight).

• PAM施用量为0、1/5000、1/2000和1/1000（PAM与干土重之比），施用方式为混合施用和表面覆盖施用，土壤为碱土和非碱土两种。