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United States Department of Agriculture

Agricultural Research Service

Title: Polyacrylamide Effects on Infiltration in San Joaquin Valley Sandy Loam Soils.

Authors
item Trout, Thomas
item Ajwa, Husein

Submitted to: ASAE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: August 1, 2001
Publication Date: N/A

Interpretive Summary: 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.

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.

Last Modified: 7/28/2014