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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 - UC DAVIS, SALINAS, CA

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 1, 2002
Publication Date: N/A

Interpretive Summary: Low infiltration rates make it difficult to irrigate effectively on some sandy loam soils on the east side of California's San Joaquin Valley. Polyacrylamide (PAM) has increased soil infiltration in other areas of the U.S., especially where soil erosion is a problem. We applied low concentrations of a high molecular weight polyacrylamide, the type that is being successfully used for furrow erosion control, in furrow irrigation water on a sandy loam soil. Two years of field scale studies and infiltrometer tests did not show any increased infiltration with PAM. There was a slight trend for the PAM to reduce infiltration rates, likely due to an increase in "apparent" viscosity when PAM is added to water. 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. Polyacrylamide will probably not be a solution for low infiltration problems in the east side of the San Joaquin valley, or other places where soils and conditions are similar.

Technical Abstract: Low infiltration rates constrain effective and economical irrigation on some sandy loam soils on the east side of California's San Joaquin Valley. Polyacrylamide (PAM) has increased soil infiltration in other areas 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 erosion control, in furrow irrigation water on Hanford sandy loam soil. 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, likely due to an increase in "apparent" viscosity when PAM is added to water. 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: 10/30/2014