SOIL-EROSION AND PESTICIDE TRANSPORT FROM AN IRRIGATED FIELD

A field experiment was conducted to study the effect of an anionic pol yacrylamide injection in irrigation water on kelthane runoff and sedim ent transport from a lima bean soil. Periodic runoff water samples fro m the polymer treated and untreated control furrows were collected fro m three irrigations and were analyzed for suspended sediments, total s ediments and kelthane residues by standard techniques. In addition, wa ter in- and outflow rates were measured periodically to calculate the effect of polymer treatment on water infiltration. The total and suspe nded sediments in the polymer treated furrows were significantly lower than the untreated ones. Kelthane concentrations in the runoff water in individual furrows were dependent on suspended solid load. During t he two post-treatment irrigations (8 h each), only 0.16 and 0.30% of t he applied kelthane was observed in the runoff from the treated and un treated plots, respectively. The present findings show promising impli cations of polymer application in reducing pesticide contamination thr ough runoff from agricultural fields.