ABSTRACT:
Polyacrylamide (PAM) has been used successfully to reduce erosion and increase infiltration on nearly a half million hectares of United States irrigated farmland. PAM is a potent and environmentally safe flocculent that greatly accelerates separation of suspended solids from water. It also improves particle cohesion, stabilizing soil structure. We hypothesized that in irrigation furrows, PAM prevents loss of weed seed and might affect weed establishment and management practices. We grew corn (Zea mays L) in plots without herbicides, or that were treated with either Eradicane (EPTC + dichlormid) or Dual II (S-Metolachlor) and irrigated in furrows that had either no PAM, or that were treated either with 10 g m−3 (10 kg ML−1 or 10 ppm) dissolved PAM during water advance, or with PAM applied as a powder patch at the furrow head. As in previous studies, erosion was greatly reduced with PAM and infiltration was increased. PAM use also reduced runoff loss of weed seeds (barnyardgrass, kochia, redroot pigweed, common lambsquarters, and hairy nightshade) 62% to 90%. Interactions of herbicide treatments and PAM on erosion, infiltration, and weed seed loss were related to the mulching effect of weed vegetation. PAM is an effective and environmentally safe means of reducing weed seed distribution in furrow irrigation water while simultaneously reducing erosion and increasing infiltration in weed-free crop production.
Footnotes
Robert E. Sojka and James A. Foerster are with U.S. Department of Agriculture - Agricultural Research Serice, Northwest Irrigation and Soils Research Lab in Kimberly, Idaho. Donald W. Morishita and Michael J. Wille are from the University of Idaho, Twin Falls Research and Extension Center in Twin Falls, Idaho.
- Copyright 2003 by the Soil and Water Conservation Society
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.