Technical Abstract: Low infiltration rates sometimes constrain effective and economical irrigation on sandy loam soils on the east side of California's San Joaquin Valley. Polyacrylamide (PAM) has increased soil infiltration in other area of the U.S., especially where soil erosion is a problem. We applied low concentrations of a high molecular weight, moderately anionic polyacrylamide, the type that is being successfully used for furrow erosio control, on Hanford sandy loam soil, in furrow irrigation water. Two years of field scale studies and two years of recirculating infiltrometer tests did not show any increased infiltration with PAM. There was a slight trend for the PAM to reduce infiltration rates. Laboratory permeameter tests showed decreasing hydraulic conductivity with increasing concentrations of PAM, likely due to an "apparent" viscosity of the solution. We conclude that PAM does not reduce aggregate breakdown and surface seal formation sufficiently for this soil under these conditions to result in increased infiltration.