Two formulations of water-soluble anionic polyacrylamide (WSPAM) are used in agriculture to reduce erosion and manage infi ltration in furrow irrigations, although few if any reports have compared their eff ectiveness. A control and two WSPAMs, a granular form and the inverse emulsion, or oil-based liquid form, were applied to irrigation water supplied to furrows formed in a silt loam soil with 1.5% slope during each irrigation from 1993 to 1999. Stock solutions prepared from the two WSPAMs in tap water were injected into furrow infl ows to attain a concentration of 10 mg L −1 only during furrow advance. During irrigations, furrow infl ow and runoff rates, and runoff sediment concentrations were measured. Crop yields were measured in fi ve of the 7 yr. Relative to controls, both WSPAM treatments reduced runoff sediment loss equally well, decreasing soil losses by 84% per irrigation, and prevented the loss of 47.8 Mg soil ha −1 over the 7-yr period. Th e yearly soil loss reductions produced by WSPAMs ranged from 66 to 99%, and may refl ect changes in the electrical conductivity (EC) of the irrigation water. Both WSPAM treatments increased the proportion of applied irrigation water that infi ltrated into newly formed furrows, but the emulsion produced the greatest overall increase in water infi ltration fraction. As a class, WSPAM treatments increased yields by 14.3% for bean ('Viva Pink' Phaseolus vulgaris L.) and 4.5% for silage corn (Zea mays L.), suggesting that the cost of WSPAM applications may be recoverable. While the two WSPAM formulations provide equivalent erosion protection, diff erences in infi ltration eff ects, product costs, and potential environmental impacts should be considered when selecting the formulation.