PAM与PG对土壤水平入渗的影响

土壤水平入渗是土壤水分空间入渗的一个重要方向，它受土壤质地和结构等多方面因素的影响，其中高分子化合物与磷石膏（PG）等的加入也对其产生重要影响。通过室内土柱试验，研究聚丙烯酰胺（PAM）和PG与土壤混合干施情况下的土壤水平入渗特征，并从机理上对试验结果进行分析研究。结果表明，由于PAM具有良好的吸水和保水性能，其用量的增加使累积入渗量增大，平均土壤含水量增加；而水平入渗速率却由于溶液粘性增大而有所降低，相应使得湿润锋推进相同距离所用时间比对照有所延长；累积入渗量与时间和湿润锋的关系，均符合Philip和Green-Ampt入渗公式，因而，在施加PAM与PG的情况下，土壤的水平入渗性能仍可用经典入渗公式来进行研究与描述；PAM和PG的加入也使土壤吸渗率发生变化，具体表现为：当PG用量相同，PAM用量的增加使得土壤的吸渗率降低。

Influence of PAM and PG on Horizontal Infiltration

Horizontal infiltration is an important direction of soil water infiltration.It is influenced by soil texture and structure and so on,amongst which,adding of high molecular compound and phosphor-gypsum also influences it significantly.The objective of this study was to investigate horizontal infiltration characteristics through indoor column experiments with PAM and PG applied in dry powder and mixed with air-dried soil.Then results were analyzed from mechanism.The results showed that owing to the good ability to absorb water and keep it of PAM,the cumulative infiltration and average water content increased with the increasing of PAM dosage.But the horizontal infiltration rate(IR) decreased which resulted from the increase of viscosity of soil solution so as to prolong the time of wetting front advancing.Relationships between accumulative infiltration and time,distance accorded with Philip and Green-Ampt infiltration formula.So horizontal infiltration still could be depicted and simulated with classic infiltration formula under the condition of adding PAM and PG.Soil infiltration rate was also changed by adding PAM and PG.When PG dosage kept constant,infiltration rate decreased with PAM dosage increase.