盐渍土的改良一般采用物理、化学、生物及工程措施，其中化学改良剂应用广泛。聚丙烯酰胺(PAM)作为高分子聚合物，能溶于水，并且有良好的凝聚作用，能够改良土壤物理结构，但是其用量的选择至关重要。本研究设计了不同的PAM浓度梯度(0.01、0.03、0.09、0.27、0.81 g/kg)进行盆栽试验，以得到改良中度盐渍障碍土壤的较适宜PAM用量。试验结果表明：PAM在盐渍土改良中较适宜的施用量为0.09 g/kg，在此施用量下，土壤电导率为最低值，为1.63 dS/m，较对照(不施PAM)下降13.42%；土壤毛管孔隙度为45.38%，较对照增加5.35%；总孔隙度为48.44%，较对照增加5%；土壤容重为1.35 g/cm³，较对照降低5.71%；饱和导水率为0.052 mm/min，较对照提升76.7%。而施用量为0.81 g/kg时，改良效果下降。该结果对使用PAM改良中度盐渍土具有一定的指导意义。

Physical, chemical, biological and engineering methods are used to improve saline soil, within which chemical amendments are widely used. Polyacrylamide (PAM) can improve soil physical structure due to its good water solubility, but it is essential to determine the appropriate applied amount to improve saline soil. A pot experiment was conducted with different PAM concentration rates (0.01, 0.03, 0.09, 0.27, 0.81 g/kg) in order to obtain appropriate applied amount of PAM to improve moderately saline soils. The results showed that 0.09 g/kg is the appropriate applied rate of PAM for saline soil improvement. Compared to the control (no PAM applied) under this rate, soil conductivity was the lowest (1.63 dS/m), decreased by 13.42%; soil capillary porosity was 45.38%, increased by 5.35%; the total porosity was 48.44%, increased by 5%; soil bulk density was 1.35 g/cm³, decreased by 5.71%; saturated hydraulic conductivity was 0.052 mm/min, increased by 76.7%. But the improvement effect fell when the applied rate of PAM was 0.81g/kg.

S156.4+2

新疆维吾尔自治区科技计划项目(201531116)，河南省科技计划项目(152102110097)和江苏省科技支撑计划项目(BE2017389)资助。