Technical Abstract: Soil erosion, although insidious, may be the greatest single threat to agricultural sustainability and to meeting future food, feed, and fiber production needs. Because agricultural yield and value are greatest from arid zone irrigated lands, and because arid zone irrigated soils are often fragile and easily eroded, concern for erosion on irrigated land is very great. Many practices have been developed to reduce erosion from all cropping systems, these concentrate on reducing the volume and energy of runoff by increasing infiltration with tillage or other practices, reducing slope and/or slope length, and anchoring soil with residues. In irrigated agriculture a new option has proven very successful, this involves use of minute amounts of long chain anionic polymers called polyacrylamides (PAMs) applied in the irrigation water. PAMs stabilize soil, preventing detachment, flocculating entrained sediment, and maintaining favorable infiltration. Anionic PAMs, with Acrylamide monomer (AMD) contents below 0.05% applied at 1 to 2 pounds per acre in irrigation streams are environmentally safe and have been shown to prevent 94% of erosion as well as reducing pollutants, microorganisms, and weed seeds from contaminating runoff. The practice is gaining wide acceptance in the U.S. and around the world because of its effectiveness, low cost (about $3 per pound) and ease of application. A million acres of U.S. land were protected from erosion by 1999.